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Hitachi Virtual Storage PlatformHitachi Copy-on-Write Snapshot User Guide

MK-90RD7013-11

Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

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iiiHitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Contents

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ixIntended audience. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xProduct version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xDocument revision level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xReferenced documents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xChanges in this revision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiDocument organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiDocument conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiiConvention for storage capacity values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xiiiAccessing product documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xiiiGetting help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xivComments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xiv

1 Overview of Copy-on-Write Snapshot . . . . . . . . . . . . . . . . . . . . . . 1-1Copy-on-Write Snapshot software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2How Copy-on-Write Snapshot works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Volume pairs: P-VOLs and V-VOLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Data pools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Licenses and capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Consistency groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5Interfaces for performing Copy-on-Write Snapshot operations . . . . . . . . . . . . . 1-5

The Storage Navigator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5Command Control Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Pair status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

2 Copy-on-Write Snapshot planning and design . . . . . . . . . . . . . . . . 2-1Consistency group system requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Data pool requirements and restrictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4Planning pair volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Planning V-VOLs and data pools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5


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Sizing the data pool workflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6Calculating the number of Copy-on-Write Snapshot pairs . . . . . . . . . . . . . . . . 2-7

Calculating SS pairs when creating external volumes or V-VOLs . . . . . . . . . 2-7Calculating maximum SS pairs based on differential tables workflow . . . . . 2-7Calculating maximum SS pairs based on shared memory workflow. . . . . . . 2-9

Calculate the capacity of the pool management block . . . . . . . . . . . . . 2-11Capacity of pool association information . . . . . . . . . . . . . . . . . . . . . . 2-12

Calculating maximum pairs based on pair tables. . . . . . . . . . . . . . . . . . . 2-12Determining maximum pairs allowed on your system . . . . . . . . . . . . . . . 2-12

Planning for splitting pairs in consistency groups . . . . . . . . . . . . . . . . . . . . . 2-12Requirements and restrictions for the At-Time Split operation . . . . . . . . . 2-13Pair inclusion in At-Time Split operations workflow . . . . . . . . . . . . . . . . . 2-13Consistency maintenance workflow when sharing SS P-VOLs with UR or TC volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14Snapshot secondary volume consistency maintenance . . . . . . . . . . . . 2-16

External volumes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16External-volume failures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

3 Copy-on-Write Snapshot installation and configuration . . . . . . . . . . 3-1Installing and removing Copy-on-Write Snapshot . . . . . . . . . . . . . . . . . . . . . . 3-2Configuration workflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Creating data pools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Creating V-VOLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Setting up the Command Control Interface command device . . . . . . . . . . . . . . 3-5

4 Sharing Copy-on-Write Snapshot volumes. . . . . . . . . . . . . . . . . . . 4-1Interoperability with other software applications and functions . . . . . . . . . . . . 4-2The Data Retention Utility and access attributes. . . . . . . . . . . . . . . . . . . . . . . 4-3Dynamic Provisioning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4Resource Partition Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5ShadowImage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Restrictions when sharing P-VOLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7TrueCopy and Universal Replicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

TC and UR volume backup in 3DC multi-target configuration . . . . . . . . . . . 4-8Volume Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Thin Image. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

5 Pair operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1Pair operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2Checking the pair status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2Pair creation workflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Pair creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Configuring pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

Removing and moving volumes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

vHitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Creating pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5Pair split . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

Splitting pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10Splitting pairs in consistency groups at a pre-determined time . . . . . . . . . 5-10

Pair resynchronization and restoration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11Resynchronizing and restoring pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

Pair deletion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12Deleting pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

6 Copy-on-Write Snapshot monitoring and maintenance . . . . . . . . . . 6-1Monitoring the storage system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

Monitoring pair information, license capacity, status . . . . . . . . . . . . . . . . . 6-2Pair status definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

Monitoring pair properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3Monitoring synchronous rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4Monitoring consistency groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4Monitoring pair operations history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4Monitoring pool information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5

Maintaining the storage system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6Managing data pools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Increasing data pool volume capacity . . . . . . . . . . . . . . . . . . . . . . . . . 6-6Changing pool volume threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7Changing pool volume names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7Recovering pool volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8Deleting pool volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

Managing virtual volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8Changing virtual volume names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9Deleting virtual volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9

Switching off the storage system power and replacing the microcode . . . 6-10Switching off the power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10Replacing the microcode offline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10

7 Copy-on-Write Snapshot troubleshooting . . . . . . . . . . . . . . . . . . . 7-1General troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

Recovering from failure during pairresync -restore operation . . . . . . . . . . . 7-6Recovering a terminated HP-UX host server . . . . . . . . . . . . . . . . . . . . . . . 7-6Recovering a blocked pool workflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6Pool-related SIM entry removal workflow . . . . . . . . . . . . . . . . . . . . . . . . . 7-7

Completing Service Information Messages . . . . . . . . . . . . . . . . . . . . . . 7-7Troubleshooting with Command Control Interface. . . . . . . . . . . . . . . . . . . . . . 7-8

Identifying errors using the log on the CCI window. . . . . . . . . . . . . . . . . 7-15Identifying errors using the Command Control Interface operation log file. 7-16


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A Command Control Interface command reference. . . . . . . . . . . . . . A-1Command Control Interface commands for Storage Navigator operations . . . . . A-2Storage Navigator and Command Control Interface pair status names . . . . . . . A-2Statuses required for Command Control Interface pair operations . . . . . . . . . . A-2

B Copy-on-Write Snapshot GUI reference . . . . . . . . . . . . . . . . . . . . B-1Pools window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2Selected pool volume window. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6Create Pools wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-15

Create Pools window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-16Confirm window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-21

Expand Pool wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-22Expand Pool window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-22Confirm window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-24

Edit Pools wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-25Edit Pools window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-25Confirm window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-27

Delete Pools wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-29Delete Pools window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-29Confirm window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-31

Restore Pools window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-32Complete SIMs window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-33Select Pool window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-34Select Pool Volumes window. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-35Pool Property window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-39Create Pairs wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-40

Select Pair Configuration window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-40Select Primary Volumes window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-41Select Pool window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-45Select Secondary Volumes window . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-46Edit Mirror Units window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-48Confirm window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-49

C Pair operations (secondary window) . . . . . . . . . . . . . . . . . . . . . . C-1Pair operations workflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2Checking pair status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2Creating a pair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2

Creating pairs in a consistency group . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3Splitting pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4Resynchronizing pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4Restoring pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5Deleting pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5

Deleting a single pair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5Deleting multiple pairs related to a port or host group . . . . . . . . . . . . . . . C-5Deleting multiple pairs related to a pool. . . . . . . . . . . . . . . . . . . . . . . . . . C-6

viiHitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

D Copy-on-Write Snapshot monitoring and maintenance (secondary window) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

Monitoring the system in the secondary window. . . . . . . . . . . . . . . . . . . . . . . D-2Monitoring pair status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2

Pair status definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3Statuses required for pair operations . . . . . . . . . . . . . . . . . . . . . . . . . . D-3

Monitoring pair volume details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3Monitoring S-VOL path information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-5Monitoring number of pairs and license information . . . . . . . . . . . . . . . . . D-6Monitoring pair operation history. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-8

Maintaining the system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-9

E Copy-on-Write Snapshot GUI reference (secondary window) . . . . . E-1Pair Operation window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-2

Volume list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-3Preview list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-5Command menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-6

History window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-6Reference codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-8

C.O.W. Snapshot window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-8

Glossary

Index


viii

Preface ixHitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Preface

This guide provides instructions for performing Copy-on-Write Snapshot (SS) tasks on Hitachi Virtual Storage Platform (VSP) storage systems.

Notice: The use of the features and/or software applications described in this guide and all other Hitachi Data Systems software applications is governed by the terms of your agreements with Hitachi Data Systems.

□ Intended audience

□ Product version

□ Document revision level

□ Referenced documents

□ Changes in this revision

□ Document organization

□ Document conventions

□ Convention for storage capacity values

□ Accessing product documentation

□ Getting help

□ Comments


x Preface

Intended audienceThis document is intended for system administrators, Hitachi Data Systems representatives, and authorized service providers who are involved in installing, configuring, and operating the Hitachi Virtual Storage Platform storage system.

Readers of this document should meet the following requirements:• Have a background in data processing and understand RAID storage

systems and their basic functions.• Be familiar with the Hitachi Virtual Storage Platform storage system, and

have read the Hitachi Virtual Storage Platform User and Reference Guide.

• Be familiar with the Storage Navigator (SN) software for the Hitachi Virtual Storage Platform storage system and have read the Hitachi Storage Navigator User Guide.

Product versionThis document revision applies to Hitachi Virtual Storage Platform microcode 70-06-2x or later.

You must have Storage Administrator (Local Copy) role to perform Compatible FlashCopy® V2 operations in the SN.

Document revision level

Referenced documentsHitachi Virtual Storage Platform documentation:• Hitachi Command Control Interface Installation and Configuration

Guide, MK-90RD7008

Revision Date Description

MK-90RD7013-00 October 2010 Initial release.

MK-90RD7013-01 December 2010 Supersedes and replaces MK-90RD7013-00.

MK-90RD7013-02 April 2011 Supersedes and replaces MK-90RD7013-01.

MK-90RD7013-03 August 2011 Supersedes and replaces MK-90RD7013-02.

MK-90RD7013-04 November 2011 Supersedes and replaces MK-90RD7013-03.

MK-90RD7013-05 March 2012 Supersedes and replaces MK-90RD7013-04.

MK-90RD7013-06 June 2012 Supersedes and replaces MK-90RD7013-05.

MK-90RD7013-07 November 2012 Supersedes and replaces MK-90RD7013-06.

MK-90RD7013-08 January 2013 Supersedes and replaces MK-90RD7013-07.

MK-90RD7013-09 July 2013 Supersedes and replaces MK-90RD7013-08.

MK-90RD7013-10 December 2013 Supersedes and replaces MK-90RD7013-09.

MK-90RD7013-11 September 2014 Supercedes and replaces MK-90RD7013-10

Preface xiHitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

• Hitachi Command Control Interface User and Reference Guide, MK-90RD7010

• Hitachi Virtual Storage Platform Provisioning Guide for Open Systems, MK-90RD7022

• Hitachi ShadowImage® User Guide, MK-90RD7024• Hitachi Storage Navigator User Guide, MK-90RD7027• Hitachi Storage Navigator Messages, MK-90RD7028• Hitachi Universal Volume Manager User Guide, MK-90RD7032• Hitachi Virtual Storage Platform User and Reference Guide, MK-

90RD7042

Changes in this revision• Added error codes 97D6 and 97D7 to Troubleshooting with Command

Control Interface on page 7-8.

Document organizationThe following table provides an overview of the contents and organization of this document. Click the chapter title in the Chapter column to go to that chapter. The first page of each chapter provides links to the sections in that chapter.

Chapter Description

Overview of Copy-on-Write Snapshot on page 1-1

Provides an overview of SS.

Copy-on-Write Snapshot planning and design on page 2-1

Describes the storage system and operational requirements.

Copy-on-Write Snapshot installation and configuration on page 3-1

Provides instructions for installing and configuring SS.

Sharing Copy-on-Write Snapshot volumes on page 4-1

Provides information about sharing SS volumes with other Hitachi Data Systems features and software applications.

Pair operations on page 5-1

Provides instructions for pair operations.

Copy-on-Write Snapshot monitoring and maintenance on page 6-1

Provides instructions for monitoring and maintaining pairs.

Copy-on-Write Snapshot troubleshooting on page 7-1

Provides troubleshooting information.

Command Control Interface command reference on page A-1

Provides command line interface (CLI) commands for SS operations.


xii Preface

Document conventionsThis document uses the following typographic conventions:

This document uses the icons in the following table to draw attention to information:

Copy-on-Write Snapshot GUI reference on page B-1

Describes SS windows and dialog boxes in SN.

Pair operations (secondary window) on page C-1

Provides instructions for pair operations using the previous SN graphical user interface (GUI), which opens in a secondary window.

Copy-on-Write Snapshot monitoring and maintenance (secondary window) on page D-1

Provides information for checking status and other information using the previous SN GUI, which opens in a secondary window.

Copy-on-Write Snapshot GUI reference (secondary window) on page E-1

Describes SS windows and dialog boxes in the previous SN GUI, which opens in a secondary window.

Chapter Description

Convention Description

Bold Indicates text on a window or dialog box, including window and dialog box names, menus, menu options, buttons, items, and labels. Example: Click OK.

Italic Indicates a variable, which is a placeholder for actual text provided by the user or system. Example: copy source-file target-fileNote: Angled brackets (< >) are also used to indicate variables.

screen/code Indicates text that is shown on screen or entered by the user. Example: # pairdisplay -g oradb

< > angled brackets Indicates a variable, which is a placeholder for actual text provided by the user or system. Example: # pairdisplay -g <group>

Note: Italic font is also used to indicate variables.

[ ] square brackets Indicates optional values. Example: [ a | b ] indicates that you can choose a, b, or nothing.

{ } braces Indicates required or expected values. Example: { a | b } indicates that you must choose either a or b.

| vertical bar Indicates that you have a choice between two or more options or arguments. Examples:[ a | b ] indicates that you can choose a, b, or nothing.{ a | b } indicates that you must choose either a or b.

Underline Indicates the default value.Example: [ a | b]

Preface xiiiHitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Convention for storage capacity valuesPhysical storage capacity values (such as disk drive capacity) are calculated based on the following values:

Logical storage capacity values (such as logical device capacity) are calculated based on the following values:

Accessing product documentationThe Hitachi Virtual Storage Platform user documentation is available on the Hitachi Data Systems Support Portal: https://portal.hds.com. Please check this site for the most current documentation, including important updates that may have been made after the release of the product.

Icon Meaning Description

Tip Provides helpful information, guidelines, or suggestions for performing tasks more effectively.

Note Calls attention to important and/or additional information.

Caution Warns users of adverse conditions and consequences, such as disruptive operations.

WARNING Warns users of severe conditions and consequences, such as destructive operations.

Physical capacity unit Value

1 KB 1,000 bytes

1 MB 1,00002 bytes

1 GB 1,0003 bytes

1 TB 1,0004 bytes

1 PB 1,0005 bytes

1 EB 1,0006 bytes

Logical capacity unit Value

1 KB 1,024 bytes

1 MB 1,024 KB or 1,0242 bytes

1 GB 1,024 MB or 1,0243 bytes

1 TB 1,024 GB or 1,0244 bytes

1 PB 1,024 TB or 1,0245 bytes

1 EB 1,024 PB or 1,0246 bytes

1 block 512 bytes

https://hdssupport.hds.com


xiv Preface

Getting helpThe Hitachi Data Systems customer support staff is available 24 hours a day, seven days a week. If you need technical support, log on to the Hitachi Data Systems Support Portal for contact information:https://portal.hds.com.

CommentsPlease send us your comments on this document: [email protected]. Include the document title, number, and revision, and refer to specific sections and paragraphs whenever possible. All comments become the property of Hitachi Data Systems.

Thank you!



1

Overview of Copy-on-Write Snapshot 1–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Overview of Copy-on-Write Snapshot

With Copy-on-Write Snapshot (SS), you can create virtual copies of a data volume in the Hitachi Virtual Storage Platform storage system.

This chapter provides instructions for planning and designing, configuring, operating, monitoring, and troubleshooting SS.

□ Copy-on-Write Snapshot software

□ How Copy-on-Write Snapshot works

□ Components

□ Licenses and capacity

□ Consistency groups

□ Interfaces for performing Copy-on-Write Snapshot operations

□ Pair status


1–2 Overview of Copy-on-Write Snapshot

Copy-on-Write Snapshot softwareSS creates a virtual, point-in-time copy, or snapshot, of a data volume. Since only changed data blocks are stored in the SS storage pool, storage capacity is substantially less than the source volume. This results in significant savings compared with full cloning methods.

The most probable types of target applications for SS are:• Database copies for decision support and database inquiries.• Non-disruptive backups from an SS secondary volume (S-VOL).• Periodic point-in-time disk copies for rapid restores in the event of a

corrupted data volume.

How Copy-on-Write Snapshot worksYou create a volume pair when you complete the following:1. Select the volume that you want to replicate.2. Identify another volume that will contain the copy.3. Associate the primary volume (P-VOL) and S-VOLs.4. Set up a data pool.5. Create the pair.

The P-VOL is updated. The virtual volume (V-VOL) points to the point-in-time data in the P-VOL and data pool and mirrors it. The V-VOL contains a virtual copy of the P-VOL; it does not contain actual data.For more information about creating pairs, see Pair creation on page 5-3.

6. Split the pair.The storage system continues to update the P-VOL. The V-VOL stops mirroring the current P-VOL. Instead, the V-VOL maintains a snapshot from the time of the split.For more information about splitting pairs, see Pair split on page 5-9.

7. Write data to the P-VOL.SS maintains the point-in-time image by copying the existing data to the data pool.

8. Resume the pair.The pool data is deleted.

Volume pairs: P-VOLs and V-VOLsA volume pair consists of a P-VOL, which contains the original and actual data, and at least one and up to 64 V-VOLs. The V-VOL is made up of pointers to the data in the P-VOL. The P-VOL and its V-VOLs are located in the same storage system. A V-VOL is also referred to as an S-VOL.

Although you must set up V-VOLs with the same capacity as the paired P-VOL, the capacity is not actually used and remains available as free storage capacity. This V-VOL sizing requirement is necessary for SS and the storage


system logic. The V-VOL pointers to data in the data pool and P-VOL reside in cache memory. Enabling your system’s cache reserves part of your system’s cache for SS.

Splitting the volume pair moves the original data to the data pool as the P-VOL is updated. The following figures show SS volumes and data pool interaction when you split the pair.

The following figure shows how the V-VOL maintains the point-in-time data when you split the pair.

The following figure shows how the V-VOL maintains the point-in-time data when you split the pair.

The following image shows how the V-VOL maintains point-in-time data when you split the pair.



Data poolsWhen you replace data in the P-VOL, the data pool holds the data. After you split a pair, the V-VOL maintains pointers to point-in-time data. If updates are written to the P-VOL before you update the block, the data that is being replaced is first copied to the data pool. The V-VOL pointer to this block is updated to the new address in the data pool. All pairs sharing the same P-VOL use a data pool.

ComponentsAn SS system typically consists of the following components:• The SN• SS and ShadowImage (SI) software• Command Control Interface (CCI)• A pair of volumes (P-VOL and S-VOL)• A data pool• A consistency group

Licenses and capacityTo use SS, SI must be installed on the same system. You must provide sufficient licensed capacity for both SS and SI.

SS uses a V-VOL management area for managing V-VOLs and data pools. The V-VOL management area is created when additional shared memory is installed.

The V-VOL management area consists of the following:• Pool management block• Pool association information


The following table shows the volumes and capacities for calculating the usable capacity for SS. The total applicable capacity must be less than the capacity you have licensed for SS. If you need more licensed capacity, call the Support Center.

Related topics• Calculating maximum SS pairs based on shared memory workflow on

page 2-9.

Consistency groupsDefine SS pair operations in consistency groups to perform the operations on multiple pairs at the same time. Set up consistency groups during pair creation.

For more information about creating pairs, see Pair creation on page 5-3.

Interfaces for performing Copy-on-Write Snapshot operations

You perform setup and pair operations using a combination of the following:• The SN. For more information about the SN, see The Storage Navigator

on page 1-5.• Command Control Interface (CCI). For more information about CCI, see

Command Control Interface on page 1-6.

The Storage NavigatorThe Storage Navigator (SN) is connected to the Hitachi Virtual Storage Platform storage system through the TCP/IP local-area network (LAN). The SN communicates and exchanges data directly with the service processor (SVP) of the connected storage system.

Use the SN to do the following:• Create the data pools and V-VOLs. For more information:

About creating data pools, see Creating data pools on page 3-2. About creating V-VOLS, see Creating V-VOLs on page 3-4.

• View pair and data pool status. For more information:

Volumes to be addedApplicable capacitySoftware Volume type Normal VOL or

DP-VOL

SS P-VOL Normal VOL Volume capacity

DP-VOL Pool capacity used by the volume

Pool volume (pool-VOL)

Normal VOL Volume capacity



About viewing pair status, see Monitoring pair information, license capacity, status on page 6-2.

About viewing data pool status, see Monitoring pool information on page 6-5.

Command Control Interface Use CCI to perform pair operations. CCI is set up on the host server. SS commands are sent from CCI to a command device on the storage system and is volume dedicated to CCI communications. Other Hitachi Data Systems software applications cannot use this volume.

Pair statusThe status of a pair is an indicator of its condition. You check the status to see when an operation is completed or when an operation can be done. For more information about monitoring pair information, license capacity, and status, see Monitoring pair information, license capacity, status on page 6-2.

2

Copy-on-Write Snapshot planning and design 2–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Copy-on-Write Snapshot planning anddesign

This chapter describes requirements for setting up and using SS and includes data pool sizing information.

□ Consistency group system requirements

□ Data pool requirements and restrictions

□ Planning pair volumes

□ Calculating the number of Copy-on-Write Snapshot pairs

□ Planning for splitting pairs in consistency groups

□ External volumes


2–2 Copy-on-Write Snapshot planning and design

Consistency group system requirementsThe following table includes a list of consistency group system requirements.

Note: Many of these requirements are augmented with restrictions.

Item Requirement

Software SI is required to operate SS. Install and enable the Virtual Storage Platform (VSP) storage system hardware, microcode, and software required for SI operations.

License capacity Consider the capacity of the volume when purchasing licensed capacity. Capacity for SS is part of the licensed capacity for SI. Ensure that the licensed capacity for SI is more than the combined capacity needed for both software applications.The number of software applications using a volume does not increase the amount of licensed capacity that you must purchase.

Shared memory Required:• SS/VFS1: 716.8 MB (RACK model is supported up to

VFS1.)• SS/VFS2: 1,021 MB (VFS1 + 307 MB)• SS/VFS3: 2,045 MB (VFS1,2 + 1024 MB)• SS/Extension 1: 4,096 MB (SS/VFS1 + 3379.2 MB)VSP storage systems can handle a 7.15 TB database with seven generations.Verify that your system is installed with the appropriate SS V-VOL management area.Restriction:• You cannot share the V-VOL management area

memory with Dynamic Provisioning (HDP).

CCI CCI is required for you to perform SS pair operations. CCI requires that you use one volume as a command device.For more information about setting up the CCI, see the Hitachi Command Control Interface Command Reference.


Volume type The P-VOL, V-VOL, and volumes must be logical volumes (LDEVs).For more information about volume type, see the following:• Data pool requirements and restrictions on page 2-4• External volumes on page 2-16To maintain performance levels, use the following configurations:• Do not mix normal volumes and data pool-VOLs in the

same parity group.• Ensure that the data pool-VOLs consist of LDEVs from

multiple parity groups.• Assign different processor blade identifiers to LDEVs

that make up data pool-VOLs.For more information about assigning the processor blade identifier, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

Emulation type (For P-VOL, V-VOL, and data pool-VOLs) OPEN-V

Pair configuration V-VOL limit per P-VOL: 64

RAID level Supported: RAID1, RAID1+0, RAID5, and RAID6Restriction: You cannot add a different RAID level to the data pool.

LUSE Supported: P-VOL and V-VOLNot supported: pool-VOL

CLPR The data pool must contain pool-VOLs belonging to the same cache logical partition.

Number of P-VOLs and V-VOLs

P-VOL: 16,384V-VOL: 16,384For more information about calculating the number of SS pairs, see Calculating the number of Copy-on-Write Snapshot pairs on page 2-7.

Maximum number of data pools

128(HDP, Dynamic Tiering (HDT), and Dynamic Provisioning for Mainframe (HDPz) pools) Creating pools for HDP, HDT, and HDPz reduces the number of usable pools for SS.

Pool-VOL capacity 8 GB to 4 TB

Maximum number of pool-VOLs in a data pool

1,024Restriction: You cannot register volumes that are already registered in a pool as pool-VOLs to another pool.

Expansion of data pool-VOL capacity

Allowed, even if snapshots are using the pool.

Deletion of data pool Allowed. You must first use the pool to delete the pairs.For more information about deleting pairs, see Deleting pairs on page 5-12.

Item Requirement



Data pool requirements and restrictionsTo use a volume as a data pool, the volume’s LDEV status must be “Normal” or “Normal (Quick Format)”.

You cannot use the following volumes as data pools:• LUSE or Cache Residency Manager (CRM) volumes, system disks,

command devices, quorum disks.• Volumes in “Block” status or volumes in copying process.• SS P-VOLs or V-VOLs.

Use of external volumes in pool

Allowed.For more information about external volumes, see External volumes on page 2-16.

Data drive type SAS, SATA, and SSD(Internal and external volumes) You can use pool-VOLs with different drive types in the same pool.For optimum performance, use volumes with the same drive types.

Operating system restrictions

(For HP-UX host servers only)Restriction: Create the SS pair before running the command for recognizing the device or V-VOL on the host server.Important! Do not use a volume already recognized by the host server as a V-VOL. If you do, an error can occur and the HP-UX host server can terminate.For more information about recovering terminated HP-UX host servers, see Recovering a terminated HP-UX host server on page 7-6.

Consistency groups (CG) The consistency group number. You define this number during the paircreate command.Note: If you do not specify a number, an unused number is assigned.Values: 128-255 (80 to FF).Maximum number of SS pairs per CG: 8,192 Maximum number of CGs per storage system: 256 including SI and ShadowImage for Mainframe (SIz) CGs.Restrictions:• Do not combine pairs with the same P-VOL in the

same CG.• Do not combine SI, SIz, and SS pairs in the same CG.For more information about consistency groups, see the Hitachi Command Control Interface User and Reference Guide.For more information about creating pairs using the paircreate command, see Creating pairs in a consistency group on page C-3.

Item Requirement


• Volumes which are already being used as data pools for SS or HDP (including HDT).

• Volumes used by another software application pair or migration plan.• Volumes with Protect or Read Only attribute, or the S-VOL Disable

setting.

The following are rules and restrictions regarding volumes:• You cannot use external and internal volume pool-VOLs in the same data

pool.• You must use the same pool for all pairs sharing the same P-VOL. For

example, if you pair one P-VOL with three V-VOLs, the three pairs must use the same data pool.

• You cannot use volumes that are in the different resource groups in the same data pool.

Planning pair volumesYou must set up the pair volumes and data pools before creating the pair.

For more information about planning pair volumes, see the following:• Planning V-VOLs and data pools on page 2-5

Sizing the data pool workflow on page 2-6

Planning V-VOLs and data poolsWhen you plan an SS implementation, keep the following considerations in mind:• The frequency in which you will create snapshots of the P-VOL.• The lifespan for each snapshot (V-VOL).• The number of snapshots (V-VOLs) you will create and the V-VOL limit

per P-VOL.For more information about the V-VOL limit per P-VOL, see Consistency group system requirements on page 2-2.Use copy frequency and V-VOL lifespan to determine the number of V-VOLs your system requires per P-VOL.For example: If your data must be copied every 12 hours, and business use of the V-VOL requires holding it 48 hours, set up four V-VOLs.

• The size of the data pool. Copy frequency, V-VOL lifespan, and the number of V-VOLs are factors in determining data pool size. The more time that elapses between snapshots, the longer a snapshot is held, and the more snapshots that exist all result in more data accumulating in the data pool.

Note: Set the access attributes using the Data Retention Utility (DRU).

For more information about setting the access attributes, see The Data Retention Utility and access attributes on page 4-3.



For more information about data pool sizing, see Sizing the data pool workflow on page 2-6.

Sizing the data pool workflow

Updating the P-VOL replaces and holds the P-VOL data in the data pool. The original data in the data pool is held to maintain the image of the P-VOL at the time of the snapshot.

To determine the size of the data pool, do the following:1. Measure write workload over time from the host software application to

the P-VOL. Write workload is the megabytes-per-second that are written to the P-VOL over a specific amount of time.

2. Calculate the amount of data that would accumulate during the lifespan of your V-VOLs.

3. Multiply the amount of data that accumulates by the number of V-VOLs.

The following figure shows the basic factors for data pool sizing.

When you finalize the capacity for a data pool, factor in the following:• A safety factor of 20 percent. Having a safety factor calculated in

minimizes the chances of over-filling the data pool. To factor in a safety factor of 20 percent, multiply the base data pool size by 1.2.

• Annual increase in data transactions. Your business data is likely to grow. Multiply the base pool size by the percentage of expected annual growth.


• The unit size of 256 KB. Data is copied to a pool in units of 256 KB. This is true even when the actual write data is smaller than 256 KB. In such a case, the write consumes 256 KB of the pool-VOL capacity.

Calculating the number of Copy-on-Write Snapshot pairsThe available system resources for copying pairs limits the number of SS pairs that you can create in the storage system. Confirm with your service provider that additional shared memory for differential tables and the V-VOL management area are installed on your system.

The maximum number of SS pairs supported on a system is the lowest value based on the following calculations:• The number of differential tables.

For more information about calculating based on differential tables, see Calculating maximum SS pairs based on differential tables workflow on page 2-7.

• The shared memory capacity for the V-VOL management area.For more information about calculating based on shared memory, see Calculating maximum SS pairs based on shared memory workflow on page 2-9.

• Number of pair tables.For more information about calculating based on pair tables, see Calculating maximum pairs based on pair tables on page 2-12.

If you are creating external volumes or Thin Image (HTI), HDP, or HDT V-VOLs in the storage system, see Calculating SS pairs when creating external volumes or V-VOLs on page 2-7.

Calculating SS pairs when creating external volumes or V-VOLsIf you are creating external volumes or HTI, HDP, or HDT V-VOLs in the storage system, the maximum number of SS pairs you can create is the lowest value based on the following calculations and no more than 63,232 pairs:• The value of the calculations for calculating the number of SS pairs.

For more information about calculating the number of SS pairs, see Calculating the number of Copy-on-Write Snapshot pairs on page 2-7.

• Max. num. SS pairs = Num. of external volumes + Num. of HTI, HDP, HDT, and SS V-VOLs

Calculating maximum SS pairs based on differential tables workflow

Differential tables keep track of the updates that take place in pairs. The number of these tables a pair requires depends on the size of the volumes.



A base that does not have shared memory has 26,176 differential tables. The remaining number of differential tables on a system is determined by the amount of shared memory that is installed on your system. For more information about determining this amount, see Determining maximum pairs allowed on your system on page 2-12.

When you use SS, the shared memory level is COW 1 with Extension 1 and Extension 2. The following table shows the shared memory level combinations and the number of differential tables that are associated with them.

The following software applications also use differential tables:• SI• SIz• Compatible FlashCopy® V2• Volume Migration

Using differential tables, use the following workflow to find the maximum number of pairs allowed on your system:1. The number of differential tables required for each pair.2. The maximum number of pairs your system supports based on the

number of differential tables in the storage system. To calculate the number of differential tables that are unused and available for SS pairs on the storage system, use the following calculation:(The number of differential tables used by all other software applications on the storage system) - (The total number of differential tables that are available on the storage system)

1. Calculate the number of differential tables required for one SS pair (O) using the following formula:

where:

X = Capacity of the volume in kilobytes.

Z = Number of slots that a differential table can manage (639 × 32).

Round up to the nearest whole number.

Example:

Combination Differential tables required

Base with no shared memory 26,176 tables

Extension 1 104,768 tables

Extension 2 209,600 tables

Note: “ceil” indicates that you must round up the result within the parenthesis () that follows.

ceil((X ÷ 256) ÷ Z)


In this example, you must create four differential tables to create one SS pair.

2. Calculate the maximum number of SS pairs using the following formula:

where:

T = Total number of differential tables.

D = Number of differential tables required for one SS pair.

M = Maximum number of SS pairs.

Example: This example assumes that no other software application is using differential tables, and that the number of differential tables is 57,600.

In this example, the maximum number of pairs allowed for SS is 14,400 pairs.

On the example system, you can create a maximum of 6,544 SS pairs based on differential tables.

Calculating maximum SS pairs based on shared memory workflowShared memory capacity for the V-VOL management area depends on additional shared memory. You can check the pool management block and pool association shared memory capacity in the C.O.W. Snapshot window.

For more information about this window, see C.O.W. Snapshot window on page E-8.

The following table shows a system’s shared memory capacity based on the amount of additional shared memory. This table also shows the V-VOL management area’s memory capacity.

You can calculate the maximum number of SS pairs that you can create based on the amount of additional shared memory in the V-VOL management area.

Use the following workflow to calculate the maximum number of pairs:

(16,777,216 kB ÷ 256) ÷ (639 x 32)= 3.19523, which rounds up to four.

T ÷ D = M

576,00 ÷ 4 = 14,400

Note: For an SS pair, one pair consists of a P-VOL and up to 64 V-VOLs. Generations of snapshots do not apply when you perform differential table calculations.

Shared memory Shared memory capacity

SS 751,619,276 bytes

SS Extension 1 4,294,967,296 bytes



1. Calculate the capacity of the pool management block, which is the total capacity of shared memory used by the pool-VOL (see Calculate the capacity of the pool management block on page 2-11).

2. Calculate the capacity of pool association information, which is the total capacity of shared memory used by the P-VOL (see Capacity of pool association information on page 2-12).

Example

This example assumes the following:• The V-VOL management area’s shared memory has a capacity of 716 MB

(751,619,276 bytes).• There are four pool-VOL pools, each having a capacity of 1 TB

(1,073,741,824 KB).• Each P-VOL has a capacity of 10 GB (10,485,760 KB).

Use the following formula to calculate the maximum number of SS pairs (P-VOLs) you can create in a storage system:

Using these examples, the maximum number supported based on additional shared memory in the V-VOL management area is 1,136 pairs.

The following table shows the pool capacity for shared memory and the P-VOL capacity that you can create.

Note: ceil in the formulas indicates that you must round up the result within the parenthesis () that follows.

floor in the formulas indicates that you must round down the result within the parenthesis () that follows.

The capacity (bytes) of shared memory used by the pool-VOL =ceil (floor (1,073,741,824 (KB)/256 (KB)) X 32/8,640) X 8,736 +ceil (ceil (floor (1,073,741,824 (KB)/256 (KB)) X 32/8,640) X 8,736 +ceil (ceil (ceil (floor (1,073,741,824 (KB)/256 (KB)) X 32/8,640) X 8,736= 135,713,760 + 69,888 + 8,736= 135,792,384 (bytes)The capacity of the pool management block = 135,792,384 X 4= 543,169,536 bytesThe capacity (bytes) of shared memory used by the P-VOL =ceil (ceil (10,485,760 (KB)/256 (KB))/2,048) X 8,736 +ceil (ceil (ceil (10,485,760 (KB)/256 (KB))/2,048) X 8,736= 17,472 +8,736= 26,208 (bytes)Maximum number of SS pairs (P-VOLs) = (751,619,276 - 543,169,536) / 183,456= 208,449,740 / 183,456= 1,136

Shared memory

Pool capacity (GB)

2,048 4,096 6,144 8,192 10,240

12,288

14,336

20,480 30,720

SS 26 (TB)

11 (TB)

- - - - - - -


The total capacity of pool-VOLs registered in a pool is the capacity of that pool. The capacity of the pool you want to create depends on the shared memory extension status.

The following graph roughly shows the relationship between the allowable pool capacity and the P-VOL capacity depending on the shared memory extension status.

Calculate the capacity of the pool management block

The capacity of the pool management block is the total capacity of shared memory used by the pool-VOL.

Use the following formula to calculate the capacity:

Copy capacity and creating pools

Estimate the copy capacity (the capacity of SS data to be copied to the pool) and then set the pool capacity large enough to accommodate the copy capacity. If the copy capacity varies according to time, use the maximum copy capacity in your calculation. Creating a pool when the pool capacity is insufficient can suspend the SS pairs (“PSUE” status).

SS Extension 1

224 (TB)

209 (TB)

194 (TB)

179 (TB)

163 (TB)

148 (TB)

133 (TB)

88 (TB)

12(TB)

Shared memory

Pool capacity (GB)

2,048 4,096 6,144 8,192 10,240

12,288

14,336

20,480 30,720

Capacity (bytes) of shared memory used by the pool-VOL = ceil (floor (pool-VOL capacity (KB)/256 (KB)) X 32/8,640) X 8,736 + ceil (ceil (floor (pool-VOL capacity (KB)/256 (KB)) X 32/8,640)/2,048) X 8,736 + ceil (ceil (ceil (P-VOL capacity (KB)/256 (KB)) X 32/8,640)/2,048)/1,024) X 8,736



Pool capacity and copying SS data

Copying SS data to the pool consumes the pool capacity in units of 256 KB. You must allow for this amount of pool capacity even in situations where less than that amount is consumed.

Capacity of pool association information

The capacity of the pool association information is the total capacity of shared memory used by the P-VOL.

Use the following formula to calculate the capacity:

Calculating maximum pairs based on pair tablesSS and Compatible FlashCopy® V2 (FCv2) pairs use pair tables. A pair table keeps track of the status for a pair. You use one pair table for each pair.

To calculate the maximum number of SS pairs you can create, use the following formula:

Max. num. SS pairs = The number of pair tables - The number of FCv2 pairs on the storage system

A storage system contains 1,048,575 pair tables. On the example system, you can create a maximum of 1,048,575 SS pairs based on pair tables.

Determining maximum pairs allowed on your systemTo determine the maximum number of SS pairs your system supports, use the example calculations described in the following sections:• Calculating maximum SS pairs based on differential tables workflow on

page 2-7.• Calculating maximum SS pairs based on shared memory workflow on

page 2-9.• Calculating maximum pairs based on pair tables on page 2-12.

Planning for splitting pairs in consistency groupsAt-Time Split to split pairs in a consistency group at a pre-determined time. You can At-Time Split multiple pairs and multiple pairs whose P-VOLs are shared with TrueCopy (TC) or Universal Replicator (UR) S-VOLs.

Use the following list to plan for splitting pairs in consistency groups:1. Note the requirements in Requirements and restrictions for the At-Time

Split operation on page 2-13.2. Before defining consistency groups for the pairsplit operation, read the

information in Pair inclusion in At-Time Split operations workflow on page 2-13.

Capacity (bytes) of shared memory used by the P-VOL = ceil (ceil (P-VOL capacity (KB)/256 (KB))/2,048) X 8,736 + ceil (ceil (ceil (P-VOL capacity (KB)/256 (KB))/2,048)/1,024) X 8,736


3. To share SS P-VOLs with UR or TC S-VOLs within a storage system, read the information in Consistency maintenance workflow when sharing SS P-VOLs with UR or TC volumes on page 2-14.

Requirements and restrictions for the At-Time Split operationNote the following requirements and restrictions when setting up to perform an At-Time Split operation:• You must include the pairs in the same consistency group.• The pairs must have a status of “PAIR”. For more information about pair

status, see Pair status definitions on page 6-2.• If you want to make changes to the pair, make the change in the same

consistency group according to the copy group.• Registering the At-Time Split operation:

You can split or delete pairs while registering the At-Time Split. If you create a pair, split a pair, or resynchronize a pair, the split time is rejected. To perform one of these operations, reset the registration of the At-Time Split.

Switching off the power resets the pre-determined split time. Performs the At-Time Split operation when a read/write

request—with a time stamp past the specified Split time—is received. Run a read/write request to prevent delays in the Split operation. When I/O does not occur, the storage system timer performs the Split operation.

If the split operation fails, the status all volumes in the consistency group remains the same as before the At-Time Split operation.

• If the consistency group contains a pair whose status cannot be changed, the pairsplit command can terminate abnormally (with error code EX-EWSTOT (Timeout)). The following are possible reasons: The SS P-VOL is also used as an UR S-VOL and the UR journal

capacity is insufficient. The SS license is invalid. An SS pair volume is blocked. The SS pair has a status that does not allow you to perform the

pairsplit operation.For more information about SS pair status, see Statuses required for Command Control Interface pair operations on page A-2.

The SS pair has a status that does not allow UR to run the pairsplit command.

Pair inclusion in At-Time Split operations workflowUse the following workflow to include pairs in an At-Time Split operation:1. Review the requirements for consistency groups in Consistency group

system requirements on page 2-2.



2. Place the pairs in a consistency group. Specify only one consistency group for a group defined in the CCI configuration file.

Consistency maintenance workflow when sharing SS P-VOLs with UR or TC volumes

Use the following workflow to share SS P-VOLs with UR or TC S-VOLs within a storage system and to maintain consistency:1. Place the SS pairs in a consistency group.2. Split the pair in a consistency group.

For more information about splitting pairs in consistency groups, see Splitting pairs in consistency groups at a pre-determined time on page 5-10.

The following figure shows the At-Time Split configuration with UR.

Note: Performing the pairsplit operation when the pairs are placed in a consistency group does not guarantee the acquired snapshot data to be the P-VOL data.

To guarantee that the acquired snapshot data is the P-VOL data, include pairs that do not share the same P-VOL in the consistency group.

To avoid a pairsplit operation failure, include only pairs that are in consistency groups in a group (not a consistency group) that you have defined in the CCI configuration file. When creating a pair using a group that you defined in the CCI configuration file, if another pair in the group is part of a consistency group, place the pair you are creating in the same consistency group. If you want to specify multiple consistency groups, define a group for each consistency group.

To avoid a command rejection and a generating a consistency group number that does not include the SS pair, create a pair for an At-Time Split operation when the host server is running. If the host server is down, create the pair using the consistency number. In the SN, use the Consistency Groups tab in the Local Replications window.

For more information about creating pairs using the paircreate command, see Creating pairs in a consistency group on page C-3.


The following figure shows the At-Time Split configuration with TC.



Snapshot secondary volume consistency maintenance

If you are sharing the SS P-VOL with one of the following S-VOLs, ensure the following to maintain SS S-VOL consistency:• (SI, TC, and/or UR) The pair status must be the same.

For more information: About sharing SI P-VOLs and S-VOLs with SS P-VOLs, see

ShadowImage on page 4-5. About sharing TC and/or UR pair volumes with SS P-VOL, see

TrueCopy and Universal Replicator on page 4-7.• (UR) The journal group must be the same.

For more information about sharing UR pair volumes with SS P-VOLs, see TrueCopy and Universal Replicator on page 4-7.

For more information about sharing Hitachi Data Systems software application volumes with SS P-VOL and S-VOLs, see Interoperability with other software applications and functions on page 4-2.

External volumesExternal volumes are volumes on external systems. You can connect multiple external storage systems to a VSP storage system. You can use external volumes as pool-VOLs, but this blocks the pool-VOLS and the pool.


External-volume failuresTo minimize the effects of the external-volume failure, specify one kind of volume as data pool-VOLs in a particular pool, either internal volumes or external volumes.

For more information about external systems and the solutions for the errors related to external volumes, see the Hitachi Universal Volume Manager User Guide.

3

Copy-on-Write Snapshot installation and configuration 3–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Copy-on-Write Snapshot installationand configuration

This chapter provides instructions and information for installing and configuring SS.

□ Installing and removing Copy-on-Write Snapshot

□ Configuration workflow

□ Creating data pools

□ Creating V-VOLs

□ Setting up the Command Control Interface command device


3–2 Copy-on-Write Snapshot installation and configuration

Installing and removing Copy-on-Write Snapshot1. In the SN, install SI.2. Install the SS license key.

To remove SS, complete the following:1. Delete the SS pairs, pools, and V-VOLs.

For more information about deleting SS pairs, pools, and V-VOLs, see: Deleting pairs on page 5-12. Deleting pool volumes on page 6-8. Deleting virtual volumes on page 6-9.

2. In the SN, remove SS.

Configuration workflowUse the following workflow to set up SS:1. Create the data pool.

For more information, see Creating data pools on page 3-2.2. Create the V-VOL.

For more information, see Creating V-VOLs on page 3-4.3. (Optional) Set up the CCI command device.

For more information, see Setting up the Command Control Interface command device on page 3-5.

Creating data poolsSplitting the pair replaces data in the P-VOL and stores data in the data pool. The V-VOL maintains a point-in-time image.

To create data pools, use the Create Pools window. Define the required items, as indicated with an asterisk (*). From this window, you can create the data pool and then continue to the next page where you can create LDEVs for the pools.

Size the pool according to the write workload and within the range for pool-VOL capacity.

For more information about sizing data pools, see Sizing the data pool workflow on page 2-6.

For more information about the pool-VOL capacity, see Consistency group system requirements on page 2-2.

Prerequisite information• Before creating the data pool, determine what is needed to assign pool-

VOLs.


• For more information about consistency group system and data pool requirements, see Consistency group system requirements on page 2-2 and Data pool requirements and restrictions on page 2-4.

1. In the Storage Systems tree, select Pools > Create Pools.2. In the Create Pools window, for Pool Type, select COW Snapshot.3. In the Pool Volume Selection area of the Create Pools window,

complete the following items: For Drive Type/RPM, select your system’s data drive type and RPM.

Values:- Mixable- External Storage

For RAID Level, select your system’s RAID level.

4. In the Pool Volume Selection area of the Create Pools window, click Select Pool VOLs, and complete the following:a. In the Select Pool Volumes window, in the Available Pool

Volumes table, select the pool-VOLs you want and click Add.b. Complete the following and then click OK:

- To select all pool-VOLs in the list, click Select All Pages.- To filter the rows, for Filter, click ON.- To specify the number of rows to show, click Options and make the selection.- To select pool-VOLs, select the pool-VOL from the Available Pool Volumes table and move it to the Selected Pool Volumes table.

5. In the Create Pools window, for Pool Name, type a name for the pool and then click Options.

6. In the Options area of the Create Pools window, complete the following items and then click Add: For Initial Pool ID, enter a number. For Warning Threshold, select a data pool capacity threshold.

The new pool is added to the Selected Pools table.7. Click Finish.

Caution: You cannot delete pool-VOLs that you have added. Before adding the pool-VOL, ensure that the pool-VOL settings are correct.

Note: For item descriptions, including character limits, see Create Pools window on page B-16.

Note: If you select External Storage as the drive type/RPM, a single dash (-) is shown as the RAID level, which indicates that you cannot select the RAID level.

Note: To create the data pool and then continue to the next page where you can create LDEVs for the pools, click Next.



8. In the Confirm window, click Apply.The data pool is created.

Creating V-VOLsFor more information about V-VOLs and P-VOLs, see Volume pairs: P-VOLs and V-VOLs on page 1-2.

Prerequisite Information• The data pool must exist.

For more information about creating data pools, see Creating data pools on page 3-2.

• The V-VOL must be the same size as the P-VOL.• The V-VOL recognized by the host server must have a status of “PSUS”. • You can create a maximum of 64 V-VOLs per P-VOL.• For HP-UX/Solaris and other operating systems: Do not use a volume

that is already recognized by the host server as a V-VOL. For more information about the HP-UX host servers operating system restrictions and the V-VOL requirements, see Consistency group system requirements on page 2-2.

For more information about determining how many V-VOLs you must create, how long to hold an SS, and other planning considerations, see Planning V-VOLs and data pools on page 2-5.

1. In the Storage Systems tree, select Logical Devices > LDEVs > Create LDEVs.

2. On the Create LDEVs window of the Create LDEVs wizard, for Provisioning Type, confirm that COW Snapshot is selected.

3. Complete the following items: For System Type, confirm OPEN is selected. For Emulation Type, confirm OPEN-V is selected. For LDEV Capacity, type the capacity for the new V-VOL.

Enter the capacity within the range of figures shown below the text box. Enter the number with two digits after the decimal point.

For Number of LDEVs, type the number of V-VOLs (LDEVs) you want to create.

For LDEV Name, type a name for the new V-VOL.For Prefix, type alphanumeric characters.Case-sensitive: YesFor Initial Number, type a number.Limit: 9 digitsCharacter limit: 32

Note: For item descriptions, including character limits, see Copy-on-Write Snapshot GUI reference on page B-1.


4. Click Option and complete the following items and then click Add: For Initial LDEV ID, ensure that the LDEV ID is set.

To confirm the used number and unavailable number, click View LDEV IDs, which opens the View LDEV IDs window.

For Initial SSID, enter the (storage) subsystem identifier (SSID).Characters/digits: 4-digit representation of a hexadecimal numberValues: 0004 to FFFETo confirm the created SSID, click View SSID to open the View SSID windows.

For Cache Partition, select the CLPR. For Processor Blade, assign a processor blade. To assign a specific

processor blade, click the ID for the processor blade. To assign the next available processor blade, click Auto.

The new V-VOLs are added to the Selected LDEVs table.5. Do one of the following:

To open the next page where you can create LDEVs, click Next to open the Create LDEVs window.

To confirm this operation, click Finish.6. In the Confirm window, do the following and then click Apply:

For Task Name type a name for the task.

For Go to tasks window for status, select to open the Tasks window.

More information• For more information about the tasks you can perform using the Create

LDEVs wizard and window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

• For more information about creating LDEVs and about the tasks you can perform from this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

Setting up the Command Control Interface command device

You must set up a volume on the storage system for the CCI and dedicate it as the CCI command device. This device acts as the interface between the CCI and the storage system.

For more information about how to set up the command device, see the Hitachi Command Control Interface Command Reference.

Caution: You cannot change the LDEV ID. It is automatically registered.

Note: For character and symbol limits and default values, see Complete SIMs window on page B-33.

4

Sharing Copy-on-Write Snapshot volumes 4–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Sharing Copy-on-Write Snapshotvolumes

This chapter discusses the Hitachi Data Systems software application volumes that you can share with SS P-VOLs.

□ Interoperability with other software applications and functions

□ The Data Retention Utility and access attributes

□ Dynamic Provisioning

□ Resource Partition Manager

□ ShadowImage

□ TrueCopy and Universal Replicator

□ Volume Migration

□ Thin Image


4–2 Sharing Copy-on-Write Snapshot volumes

Interoperability with other software applications and functions

You can share the following Hitachi Data Systems software application volumes with SS P-VOLs:• Dynamic Provisioning

For more information about sharing volumes with HDP, see Dynamic Provisioning on page 4-4.

• Resource Partition ManagerFor more information about sharing volumes with Res Par, see Resource Partition Manager on page 4-5.

• ShadowImageor more information about sharing volumes with SI, see ShadowImage on page 4-5.

• TrueCopy and Universal ReplicatorFor more information about sharing volumes with TC and UR, see TrueCopy and Universal Replicator on page 4-7

• Volume MigrationFor more information about sharing volumes with Volume Migration, see Volume Migration on page 4-9.

• Thin ImageFor more information about sharing volumes with HTI, see Thin Image on page 4-9.

Use the following table to determine the interoperability of other HDS software applications and function volumes with SS P-VOL and S-VOLs.

Software application and function volume types Used as SS P-VOL Used as SS S-VOL

HTI P-VOL No No

HTI S-VOL No No

SI P-VOL Yes No

SI S-VOL Yes No

TC P-VOL Yes No

TC S-VOL Yes No

UR P-VOL Yes No

UR S-VOL Yes No

Volume Migration source volume Yes No

Volume Migration target volume No No

Read Only volume Yes Yes

Protect volume Yes Yes

“S-VOL Disable” volume Yes Yes

Zero Read Capacity volume Yes Yes

Invisible volume Yes Yes


The Data Retention Utility and access attributesThe SS pair and pool operations that you can perform for volumes depend on the access attributes that you set. Set the access attributes using the SN DRU.

You can also set SS pair P-VOLs and S-VOLs access attributes and reserve volumes.

The following table shows the SS pair operations that you can perform for volumes based on the access attributes that you set.

The following table shows the SS pool operations that you can perform for volumes based on the access attributes that you set.

Note: Use the CCI to set the Zero Read Capacity and Invisible attributes.

Note: The SS volume access attributes do not change as a result of an SS operation. For example, even though the reverse resync operation reverses the P-VOL and S-VOL, the P-VOL access attribute is not overwritten to that S-VOL.

SS pair P-VOL access attribute

SS pair S-VOL access attribute

SS pair operation

Create, Split, Suspend,Delete, Resync (forward) Resync (reverse)

Read/Write Read/Write YES YES

Read Only, Protect, S-VOL Disable

NO NO

Read Only Read/Write YES NO


NO NO

Protect Read/Write YES NO


NO NO

S-VOL Disable Read/Write YES NO


NO NO

SS volume access attribute

SS pool operation

Pool-VOL setting

Read/Write YES

Read Only NO

Protect NO

S-VOL Disable NO



The SS pair status determines whether you can set access attributes for the SS P-VOL and S-VOL. The following table shows the access attributes that you can set for SS P-VOL and S-VOL.

Dynamic ProvisioningYou can share HDP volumes with SS P-VOLs. You can use a maximum HDP volume size of 4 TB (4398046511104 bytes) as an SS P-VOL.

You cannot use TB, GB, or MB specifications for SS volumes. For example, to create a 4 TB P-VOL, use the block specification. The block-size equivalent to 4 TB is 8589934592 blocks.

Note the following regarding pools:• You cannot use HDP pools (including Dynamic Tiering (HDT) pools) as

SS pools.• The number of available pools for SS decreases according to the number

of HDP pools (including HDT pools) and HDPz pools in the storage system. You can create a maximum of 128 pools in the storage system.

• If you specify an HDP V-VOL as the SS P-VOL and the capacity of the HDP V-VOL is increasing, you cannot create the SS pair.

• Performing an SS paircreate operation while zero pages are being reclaimed (including operations by Writesame, Unmap, and Rebalance) results in the zero-page operation being interrupted.

• An SS create pair operation may be rejected if the Unmap command operation is in progress with system option mode 905 ON. Retry the SS operation after a while. If the operation still fails, set system option mode 905 to OFF and retry.

SS pair status SS pair volume

Access attribute setting

Read Only, Protect,S-VOL Disable Read/Write

COPY P-VOL YES YES

S-VOL NO YES

PAIR, PFUL P-VOL YES YES

S-VOL YES YES

PSUS, PFUS P-VOL YES YES

S-VOL YES YES

SMPL P-VOL YES YES

S-VOL NO YES

RCPY P-VOL NO YES

S-VOL NO YES

PSUE P-VOL YES YES

S-VOL NO YES


Resource Partition ManagerYou can create an SS pair if the P-VOL and S-VOL are allocated to the same resource group or different resource groups. Allocate the pool you want to use to the same resource group as the P-VOL or the resource group that has an authority to create an SS pair.

For more information about resource groups, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

ShadowImageYou can share SI P-VOLs and S-VOLs with SS P-VOLs. The SI and SS pair’s status determines the pair operations you can perform.

For more information about SI pair status and operations, see the Hitachi ShadowImage® User Guide.

The following tables list the relationship between SS pair operations and SI status.

The following tables list the relationship between SS operations and SI status.

SS pair operation

SI status

COPY(PD) /COPY

PAIRCOPY(SP) /COPY

PSUS(SP) /PSUS

PSUSCOPY (RS) /COPY

COPY (RS-R) /

RCPYPSUE

Create pair Yes Yes Yes Yes Yes Yes No Yes

Split pair Yes Yes Yes Yes Yes Yes No Yes

Restore pair No No No No Yes No No Yes

Delete SS data Yes Yes Yes Yes Yes Yes Yes Yes

Delete pair Yes Yes Yes Yes Yes Yes Yes Yes

SS operation

SI status

COPY(PD)

/COPY

PAIRCOPY(SP) /COPY

PSUS (SP) /PSUS

PSUSCOPY (RS) /COPY

COPY (RS-R) /

RCPYPSUE

Create pair No No No No Yes No No No

Split pair N/A No No No Yes No No No

Split pair in a consistency group

N/A No No No Yes* No No No

Restore pair N/A No No No Yes No No No

Delete SS data N/A Yes Yes Yes Yes Yes Yes Yes

Delete pair N/A Yes Yes Yes Yes Yes Yes Yes



The following tables list the relationship between SI operations and SS status.

The following tables list the relationship between SI operations and SS status.

* The SI pair status must be “PSUS” from the time you split the pairs in a consistency group until the time the status of all SS pairs in the consistency group change to “PSUS”. If the SI pair status changes while splitting pairs in a consistency group, the SS data cannot maintain consistency.

SS operation

SI status

COPY(PD)

/COPY

PAIRCOPY(SP) /COPY

PSUS (SP) /PSUS

PSUSCOPY (RS) /COPY

COPY (RS-R) /

RCPYPSUE

SI operation

SS status

COPY1 PAIR, PFUL

PSUS, PFUS COPY2 RCPY PSUE

Create pair Yes Yes Yes Yes No Yes

Create and split pair Yes Yes Yes Yes No Yes

Split pair Yes Yes Yes Yes No Yes

Forward pair resynchronization

Yes Yes Yes Yes No Yes

Normal backward pair resynchronization


Quick backward pair resynchronization

No No No No No No

Suspend pair Yes Yes Yes Yes Yes Yes

Delete pair Yes Yes Yes Yes Yes Yes

1. “COPY” status during initial copy.2. “COPY” status during resynchronization.

SI operation

SS status

COPY2 PAIR, PFUL


Create pair No No No No No No

Create and split pair No No No No No No

Split pair Yes Yes Yes Yes No Yes

Forward pair resynchronization


Normal backward pair resynchronization


Quick backward pair resynchronization

No No No No No No

Suspend pair Yes Yes Yes Yes No Yes


Restrictions when sharing P-VOLsThe SS S-VOL uses the data in the P-VOL. The following are restrictions when sharing an SS pair P-VOL with an SI P-VOL or S-VOL:• The SS pair P-VOL cannot have the same mirror unit (MU) number as

the SI pair.• You cannot perform the SI Quick Restore operation.• You cannot share the SI volume that is in a consistency group with SS.• You cannot share the SS volume that is in a consistency group with SI.

TrueCopy and Universal ReplicatorYou can share TC and UR pair volumes with SS P-VOLs. If you share pair volumes with these software applications, the pair operation you can perform are restricted based on the shared pair status.

The following table shows the relationship between SS pair operations and TC/UR status.

The following table shows the relationship between SS pair operations and TC/UR status.


1. You can perform SI operations while splitting pairs in a consistency group. However, the SS data consistency is not maintained.

2. “COPY” status during initial copy.3. “COPY” status during resynchronization.

SI operation

SS status

COPY2 PAIR, PFUL


SS operationTC/UR status

COPY PAIR PSUS PSUE Suspending Deleting

Create pair Yes Yes Yes Yes Yes Yes

Split pair Yes Yes Yes Yes Yes Yes

Restore pair No No Yes Yes No No

Delete SS data Yes Yes Yes Yes Yes Yes



COPY PAIR PSUS PSUE SSWS Suspending Deleting

Create pair Yes Yes Yes Yes Yes Yes Yes

Split pair No Yes Yes Yes Yes Yes Yes

Restore pair* No No No No No No No

Delete SS data Yes Yes Yes Yes Yes Yes Yes



The following table shows the relationship between TC/UR pair operations and SS status.

The following table shows the relationship between TC/UR pair operations and SS status.

To view a list of the corresponding CCI pair status names, see Storage Navigator and Command Control Interface pair status names on page A-2.

TC and UR volume backup in 3DC multi-target configurationYou can use SS to back up TC and UR volumes on the remote sites in a 3DC multi-target configuration.

Delete pair Yes Yes Yes Yes Yes Yes Yes

* When restoring an SS pair whose P-VOL is used as a TC or UR S-VOL, switch operations to the remote site by running the horctakeover command.


COPY PAIR PSUS PSUE SSWS Suspending Deleting

TC/UR operation

SS status

COPY1 PAIR, PFUL


Create pair Yes Yes Yes Yes No Yes

Split pair Yes Yes Yes Yes N/A Yes

Resync pair Yes Yes Yes Yes No Yes


Switch operations to the remote site


1. “COPY” is the status during the initial copy.2. “COPY” is the status during a resynchronization.

TC / UR operations

SS status

COPY1 PAIR, PFUL


Create pair 3 No No No No No No

Split pair Yes Yes Yes Yes N/A Yes

Resync pair Yes Yes Yes Yes N/A Yes

Delete pair Yes Yes Yes Yes N/A Yes

Switch operations to the remote site

Yes Yes Yes Yes N/A Yes

1. “COPY” is the status during the initial copy.2. “COPY” is the status during a resynchronization.3. To use a TC or UR S-VOL as the SS P-VOL, you must first create the TC or UR pair

then create the SS pair.


The following figure shows how to back up the volumes.

Pair 1 is the TC pair. Pair 2 is the UR pair. Pair 3 is the UR pair for a delta resynchronization. Pair 4, pair 5, and pair 6 are the SS pairs.

To back up the volumes, complete the following:1. Create the 3DC multi-target and delta resynchronize pairs (pairs 1, 2,

and 3).2. Create pair 4.3. Create pairs 5 and 6.

Volume MigrationTo share the source Volume Migration pair with an SS P-VOL, complete the following:1. Create the SS pair.2. Perform the migration plan.

To share SS P-VOL, the SS pair status must be “PAIR”. You can delete and cancel the migration plan at any time.

For more information about using Volume Migration, call the Support Center.

Thin ImageYou can share HTI pair volumes with SS, HDP, and HDPz pairs.

Note the following regarding pools:• You cannot use HTI pools for SS.• You cannot use SS pools for HTI.

Note: You cannot share SS volumes in 3DC UR/UR configurations.



• The more pools that you create for HTI, the less pools that are available for SS.

5

Pair operations 5–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Pair operations

This chapter provides instructions for performing pair operations.

□ Pair operations

□ Checking the pair status

□ Pair creation workflow

□ Pair split

□ Pair resynchronization and restoration

□ Pair deletion


5–2 Pair operations

Pair operationsYou can perform the following operations on pairs:• Checking the pair status on page 5-2.• Pair creation on page 5-3. The V-VOL becomes a virtual duplicate of the

PVOL.• Pair split on page 5-9 A point-in-time snapshot of the P-VOL is

established in the V-VOL, allowing another software applications to use the V-VOL.

• Pair resynchronization and restoration on page 5-11. SS data is discarded and the V-VOL is again a virtual copy of the P-VOL.

• Pair deletion on page 5-12. The pair relationship between the pair volumes is ended.

Checking the pair statusEach pair operation requires a pair to have a specific status. Check the pair status before performing a pair operation and to ensure that an operation completes successfully.

For more information about checking pair status, see Monitoring the storage system on page 6-2.

For the more information about the statuses that are required for specific operations, see Pair status definitions on page 6-2.

Pair creation workflowUse the following workflow to create a pair:1. (If you are sharing SS P-VOLs with other Hitachi Data Systems software

application volumes and you want to use the volumes to create the SS pair) Set the access attributes using the SN DRU.For more information about setting access attributes, see The Data Retention Utility and access attributes on page 4-3.

2. Create the data pool.For more information about creating data pools, see Creating data pools on page 3-2.

3. Create the V-VOL for the pair.For more information about creating V-VOLs, see Creating V-VOLs on page 3-4.

4. Check the pair status.For more information about checking the pair status, see Checking the pair status on page 5-2.

5. Do the following: If you are creating pairs with different numbers of S-VOLs, configure

the pairs.


For more information about configuring pairs, see Configuring pairs on page 5-3.

If you are creating pairs with the same number of S-VOLs, create the pairs.For more information, see Creating pairs on page 5-5.

Pair creationWhen you create a pair, the V-VOL becomes a virtual copy of the P-VOL. Updates you make to the P-VOL are reflected in the V-VOL until you split the pair.

Related topics• Prerequisite information on page 5-3• Configuring pairs on page 5-3• Creating pairs on page 5-5

Prerequisite information• The data pool must exist.

For more information about creating data pools, see Creating data pools on page 3-2.

• The V-VOL for the pair must exist.For more information about creating V-VOLs, see Creating V-VOLs on page 3-4.

• The P-VOLs and S-VOLs must be equal in size.• Review the pair volume requirements.

For more information, see Planning pair volumes on page 2-5.• The pair volumes must be in “SMPL” status.• You must use the same pool for all pairs sharing a single P-VOL.

Example: Three pairs with the same P-VOL must use the same pool.• In the Create Pairs wizard, specify the pair configuration settings.

For more information about setting up pair configuration, see Configuring pairs on page 5-3.

Configuring pairsIf you are creating pairs with different numbers of S-VOLs, do the following to create the pair:

Note: After you create the pair, if the number of pairs and other information shown in the Summary tab differs from the number of pairs in the list on the window, configuration changes may be in progress. If configuration changes are in progress, wait until they have completed and then click File > Refresh All to read the configuration information.



1. Specify the maximum number of secondary pairs, even if a pair will not have that many S-VOLs.

2. Remove volumes or move volumes to the correct location. For more information about removing and moving volumes, see Removing and moving volumes on page 5-4.

Example 1

You want to create a pair using one P-VOL and one S-VOL. For Number of Secondary Volumes, type 1.

You want to create a pair using one P-VOL and 64 S-VOLs (the maximum). For Number of Secondary Volumes, type 64.

Example 2

You want to add a new S-VOL to an existing pair, as shown in the following diagram.

For Number of Secondary Volumes, type 2.

Example 3

You want to create one pair with two S-VOLs and another pair with one S-VOL. For Number of Secondary Volumes, type 2.

In this case, the storage system assumes that you are creating two pairs, each having two S-VOLs, as shown in the following figure.

Removing and moving volumes1. In the Storage Systems tree, click Replications > Local

Replications > Pairs.2. In the Pairs tab of the Local Replications window, click Create Pairs.


3. In the Select Pair Configuration window, for Number of Secondary Volumes, type the number of S-VOLs that you want to pair, and then click Next.

4. In the Select Primary Volumes window, select two LDEVs as P-VOLs, and then click Next.

5. In the Select Secondary Volumes window, complete the following and then click Next:a. Select three LDEVs from the Available LDEVs table as the S-VOLs.b. In the Selected Pairs table, delete the unwanted row by selecting it

and clicking Remove.The volumes are removed and moved.

Creating pairsUse this procedure if you are creating pairs with the same number of S-VOLs. Use the Create Pairs wizard to create pairs.

1. Open the Create Pairs wizard. Complete one of the following: Click General Tasks > Create Pairs. In the Storage Systems tree, click Replications > Local

Replications > Pairs > Create Pairs.2. In the Select Pair Configuration window of the Create Pairs wizard,

complete the following items and then click Next: For Copy Type, select COW Snapshot. For Emulation Type, OPEN-V is selected by default.

For Number of Secondary Volumes, type the number of S-VOLs according to the pair configuration with the largest amount of S-VOLs that you are creating.For more information about setting up the pair configuration, see Configuring pairs on page 5-3.

For Initial MU Number, type an MU number.

Note: If you are using SS, Split Type, Copy Pace, and Pair Topology Type are unavailable.

Note: If the pair is in “SMPL (PD)” status, you cannot create the pair. To shorten the period when the pair is in “SMPL (PD)” status, do the following:1. Resynchronize the pair. For more information about resynchronizing

pairs, see Resynchronizing and restoring pairs on page 5-11.2. Wait until the pair status changes to “PAIR”.3. Delete the pair. For more information about deleting pairs, see Deleting

pairs on page 5-12.

Note: If you are using SS, this item is unavailable.



3. In the Select Primary Volumes window, for Use Primary Volumes of Snapshot Pairs, select the kind of volumes you want to populate from the Available LDEVs table.Values: Yes. The LDEVs that are already used as P-VOLs are shown. No. The LDEVs that are not used as P-VOLs are shown.

4. To create pairs with LDEVs that are not paired and are not listed in the Available LDEVs table, add an available pool. Do the following:a. Click Select Pool.b. In the Select Pool window, select a pool and click OK.The LDEV is added and is listed in the Available LDEVs table.


5. In the Available LDEVs table, select the LDEV that you want to be the P-VOL and click Add. The LDEV moves to the Selected LDEVs table.

6. Click Next.7. In the Select Secondary Volumes window, pair the LDEV to the P-VOL

LDEV. Repeat this step until all LDEVs are paired with a P-VOL LDEV:a. Select the S-VOL LDEV ID from the Available LDEVs table.b. (If you specified multiple P-VOLs) From the Selected Pairs table,

select the LDEV ID for the P-VOL to which you want the S-VOL to be paired, and click Set.

Note: If you do not select a P-VOL, the selected S-VOL is paired to P-VOLs in the order they are listed in the table.



8. Sort the Available LDEVs and Selected Pairs tables according to the capacity you select in the Capacity list.

9. You can do the following from this window: Correct mirror unit numbers by selecting the line in the Selected

Pairs table and clicking Edit Mirror Unit. Remove a configuration. To do this, select the line you want to

remove from the Selected Pairs table and click Remove.For more information about creating unequal pair configurations and removing configurations, see Example 3 on page 5-4.The following figure shows the right-side of the Select Secondary Volumes window.


10.Click Next.11.In the Confirm window, for Task Name, type a name and then click

Apply.

Pair splitSplitting a pair creates a virtual point-in-time copy of the P-VOL and stores SS data in the pool. Splitting a pair does the following to the P-VOL:• It continues receiving updates from the host, but updates are not

reflected in the V-VOL.• The data blocks are copied to the data pool. Pointers in the V-VOL follow

this original data to the data pool, maintaining the point-in-time copy.

You can do the following to split pairs:• Split a pair.

For more information about splitting pairs, see Splitting pairs on page 5-10.

• Split multiple pairs in a consistency group.For more information about splitting pairs in a consistency group, see Splitting pairs in consistency groups at a pre-determined time on page 5-10.




• Split multiple pairs in a consistency group at a pre-determined time.For more information about splitting pairs in a consistency group, see Splitting pairs in consistency groups at a pre-determined time on page 5-10.

For more information about the consistency group requirements for splitting pairs, see Consistency group system requirements on page 2-2.

Related topics• Prerequisite information on page 5-10• Splitting pairs on page 5-10• Splitting pairs in consistency groups at a pre-determined time on page

5-10

Prerequisite information• The pair status must have a status of “PAIR”.• If you pair a P-VOL with two or more V-VOLs, the pairs must have a

status other than “RCPY”. If the status is “RCPY”, the pairsplit operation can end abnormally.

• SS does not support Quick Split mode.

Splitting pairsYou can also split pairs in consistency groups.

For more information about splitting pairs in a consistency group, see Splitting pairs in consistency groups at a pre-determined time on page 5-10.1. In the Storage Systems tree, click Replications > Local

Replications > Pairs.2. In the Pairs tab, select the pair you want to split, click Split Pairs, and

then click Finish. 3. In the Confirm window, for Task Name, type a name for the task and

then click Apply.

The pairs are split. The pair status changes to “PSUS”.

Splitting pairs in consistency groups at a pre-determined timeUse the At-Time Split operation to split pairs in a consistency group at a pre-determined time.

Note: If you are performing the pairsplit operation on a pair that shares the same P-VOL, do not run the pairresync -restore command on the pair. Running the command during this operation can result in the pairsplit operation ending abnormally.



Prerequisite information• The CCI must be installed.1. From a command prompt, run the following command, specifying a

consistency group number in the command option:paircreate

The At-Time SS function is enabled.2. (Optional) Create more pairs specifying the same consistency group

number.3. From a command prompt, run the following command on the

consistency group:pairsplit

The VSP storage system receives the command. Running a subsequent write requests from the host to the P-VOL of a pair in the consistency group acquires SS data.

Related topics

Planning for splitting pairs in consistency groups on page 2-12

Pair resynchronization and restoration Resynchronizing a pair does the following:• Increases capacity in the data pool.• Deletes data in the pool.• Mirrors the V-VOL with the current data in the P-VOL.

Reverse resynchronizing a pair restores the P-VOL using data from the V-VOL.

Related topics• Prerequisite information on page 5-10• Resynchronizing and restoring pairs on page 5-11

Prerequisite information• The pair must be in “PSUS” status.• SS does not support high speed mode, even if you specify it.• If a failure occurs when you reverse resynchronize a pair, the pair status

changes to “PSUE”. To restore the pair, you must delete the SS data. However, when you do this, the pair’s P-VOL data cannot be guaranteed. Therefore, take appropriate measures, such as overwriting the backup data to the P-VOL or formatting the P-VOL.

Resynchronizing and restoring pairs1. In the Storage Systems tree, click Replications > Local

Replications > Pairs.



2. In the Pairs tab, select the pairs you want to resynchronize, then click Resync Pairs.

3. In the Resync Pairs window, for Resync Type, select one of the following and then click Finish: If you have split or deleted the pool data, to resynchronize the pair,

select Normal Copy (Primary > Secondary). To reverse resynchronize the volumes from the S-VOL to the P-VOL,

select Reverse Copy (Secondary > Primary). All differential data is updated to the P-VOL.

4. On the Confirm window, for Task Name, type a name for the task and then click Apply.

The pair is resynchronized and restored.

Pair deletionDeleting a pair ends the SS relationship between the P-VOL and V-VOL. The following also occurs:• SS data for the pair is deleted from the data pool.• The status changes to “SMPL (PD)”. When the operation is complete, the

status changes to “SMPL”.

Related topics• Prerequisite information on page 5-10• Deleting pairs on page 5-12

Prerequisite information

The pair status must be “PAIR”, “PSUS”, or “PSUE”.

Deleting pairs1. In the Storage Systems tree, click Replications > Local

Replications > Pairs.2. In the Pairs tab, select the pair you want to delete, and click More

Actions > Delete Pairs.


Note: The time required to delete a pair or pairs can be from several seconds to more than ten minutes. The time increases when you delete multiple pairs at the same time or if you use a large area of the pool for SS data.

Note: After you delete the pair, if the number of pairs and other information shown in the Summary tab differs from the number of pairs in the list on the window, configuration changes may be in progress. If configuration changes are in progress, wait until they have completed and then click File > Refresh All to read the configuration information.


3. In the Delete Pairs window, for Task Name, type a name for the task and then click Apply.

The pair is deleted.

Note: For more information about character and symbol limits and default values, see Complete SIMs window on page B-33.

6

Copy-on-Write Snapshot monitoring and maintenance 6–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Copy-on-Write Snapshot monitoringand maintenance

This chapter provides information and instructions for monitoring and maintaining SS.

□ Monitoring the storage system

□ Maintaining the storage system


6–2 Copy-on-Write Snapshot monitoring and maintenance

Monitoring the storage systemMonitoring the storage system helps you to keep track of pairs and volumes in current and past conditions. Monitoring is an ongoing activity.

Monitoring the storage system includes the following activities:• Monitoring pair information, license capacity, status on page 6-2 (status

definitions included)• Monitoring pair properties on page 6-3• Monitoring synchronous rates on page 6-4• Monitoring consistency groups on page 6-4• Monitoring pair operations history on page 6-4• Monitoring pool information on page 6-5

Monitoring pair information, license capacity, statusYou can view basic pair information, license capacity, and pair statuses from the Local Replications window. Monitor pair status before and after performing pair operations.

Each operation requires a specific status or statuses. To do a pair command, first check the pair’s status. Check the pair status to ensure that the pairs are operating correctly and that status is changing to the appropriate state during and after an operation.

Monitor pair information, license capacity, and status frequently using the SN GUI. You can set up email notifications for problems that occur in pair operations using SN.1. In the Storage Systems tree, click Replications > Local

Replications.2. In the Pairs tab, locate the pair whose status you want to review.

Review pair status in the Status column.

Pair status definitions

Click Refresh View to ensure the pair status data is current.

Note: Both SS and SI pairs are shown in the Pairs tab.• Use the Copy Type column to find SS pairs.• SS V-VOLs are shown in the Secondary Volume column.

Caution: (Using monitoring software applications on a host server) If you have installed and are running a software application on a host server to monitor the volumes of SS pairs, the following problems can occur:• An S-VOL whose status is not “PSUS” (or “PFUS”) rejects access from

the host server, possibly causing problems for the monitoring software application whose access is rejected.

• If the host server connects to more than one port, other ports may also go offline when the S-VOL rejects host server access.

To solve these problems, stop the monitoring software application.


For more information about the corresponding CCI pair status names, see Storage Navigator and Command Control Interface pair status names on page A-2.

The following table shows the pair status and descriptions. The P-VOL and V-VOL access columns in the following table indicate whether the volumes accept read/write.

Monitoring pair propertiesYou can view data related to pairs and their volumes, including volume capacity, status, P-VOLs and S-VOLs, identifiers, and several other details.1. In the Storage Systems tree, click Replications > Local

Replications.2. In the Local Replications window, select the pair and then click More

Actions > View Pair Properties.The pair properties are shown in the View Tier Properties window.

Status Description P-VOL access V-VOL access

SMPL(PD) The pair is in the process of being deleted. You cannot perform pair operations while the pair is in this status. After the pair is deleted, the status changes to “SMPL”.

Yes R/W disabled

COPY The storage system has accepted the paircreate initial copy. The storage system accepts read/write operations to the P-VOL, but does not accept read/write operations to the S-VOL.

Yes R/W disabled

PAIR The volumes are paired. The storage system does not accept read/write operations to the S-VOL.

Yes R/W disabled

PSUS The snapshot is split. The storage system accepts read/write operations to the S-VOL. Differential data between the P-VOL and S-VOL is retained. You can immediately perform the resync operation.

Yes R/W enabled. Can be mounted.

PFUL The data pool threshold is exceeded in “PAIR” status. Yes R/W disabled

PFUS The data pool threshold is exceeded in “PSUS” status. Yes R/W enabled

RCPY* The pair is in the process of reverse pairresync. The storage system does not accept read/write operations to the S-VOL. Only the S-VOL differential data is copied to the P-VOL.

Yes R/W disabled

PSUE The storage system has suspended the pair. The storage system accepts read/write operations to the P-VOL, but does not accept read/write operations to the S-VOL.

Yes R/W disabled

* Starting time of the copy depends on numbers of pairs and your system environment.

Caution: When you run DEVSERVE to a read/write disabled volume, the message INTERVENTION REQUIRED appears. If you have created pairs with the volumes online, and then run DEVSERVE to a read/write disabled volume, a normal value is returned.



Monitoring synchronous ratesYou can check on the percentage of data that is synchronized between the P-VOLs and S-VOLs.

1. In the Storage Systems tree, click Replications > Local Replications.

2. In the Local Replications window, select the pair and click More Actions > View Pair Synchronous Rate.The synchronous rates are shown in the View Pair Synchronous Rate window.

Monitoring consistency groupsYou can check the number and individual properties for consistency groups.1. In the Storage Systems tree, click Replications > Local

Replications.2. In the Local Replications window, view the number of consistency

groups in the Summary table.3. To view a list of consistency groups with status and number of pairs, click

the Consistency Groups tab.4. On the Consistency Groups tab, click the CTG ID link to view a

consistency group’s properties.

Monitoring pair operations historyYou can review the operations that have been performed on a pair using the View History window.1. In the Storage Systems tree, click Replications > View Histories.2. In the View Histories window, for Copy Type, select COW Snapshot.

The Description column indicates which operations ran. The following table contains descriptions and explanations of the code.

Note: You can show the latest synchronous rate by clicking Refresh View. If you close the window, information in the Local Replications window may not be the latest. Click Refresh View again.

Code Description Explanation

2001 PAIR The pair has been created.

2011 PSUS The pair has been split.

2021 SMPL The pair has been deleted.

2030 COPY(RS-R) START The pair restoration operation has begun.

2031 COPY(RS-R) END The pair restoration operation is completed.

2032 COPY(RS-R) ENDED ABNORMAL

The pair restoration operation has failed.

2051 COPY(RS) The pair has been resynchronized and SS data has been deleted.


Monitoring pool information1. In the Storage Systems tree, click Pools.2. From the names that appear on the Pools tab, click the pool that you

want to review.3. In the Pools window on the right pane, review the desired pool

information.

You can do the following to monitor pool information:• Copy-on-Write Snapshot installation and configuration on page 3-1• Copy-on-Write Snapshot monitoring and maintenance on page 6-1• Changing pool volume names on page 6-7• Managing data pools on page 6-6

2070 PSUE(ABNORMAL END) A failure occurred. The pair has been suspended.

2040 INITIALIZE START Initialization processing began.

2041 INITIALIZE END Initialization processing terminated normally.

2042 INITIALIZE ENDED ABNORMAL

Initialization processing terminated abnormally.

Code Description Explanation



Maintaining the storage systemYou can maintain the storage system while monitoring it. Some of the maintenance tasks you will do are in response to a particular behavior in the storage system. Other maintenance tasks are in response to requirements changes, which you can do by changing the storage system settings.

Maintaining the storage system, data pools, and V-VOLs includes the following activities:• Managing data pools on page 6-6• Managing virtual volumes on page 6-8• Switching off the storage system power and replacing the microcode on

page 6-10

Managing data poolsYou can perform the following maintenance operations to manage data pools:• Increasing data pool volume capacity on page 6-6• Changing pool volume threshold on page 6-7• Changing pool volume names on page 6-7• Recovering pool volumes on page 6-8• Deleting pool volumes on page 6-8

Increasing data pool volume capacity

If the pool threshold is reached more than once or twice, increase the data pool-VOL capacity. The best practice is to prevent the pool from reaching full capacity by monitoring the pool usage rate.

You increase the data pool-VOL capacity by adding pool-VOLs to the data pool. You can check the capacity in the Pools window.

For more information about monitoring pool information, see Monitoring pool information on page 6-5).1. In the Storage Systems tree, click Pools.2. From the names that appear on the Pools tab, click the pool with the

capacity you want to increase.3. In the Pools window, click Expand Pool.4. In the Expand Pool window, click Select Pool VOLs.5. In the Available Pool Volumes table that is shown in the Select Pool

Volumes window, select the LDEV you want and then click Add.The LDEV is moved to the Selected LDEVs table.

6. Click OK.In the Expand Pool window, the number of selected pool-VOLs and total capacity is shown.

7. Click Finish.


8. In the Confirm window, complete the following and click Apply: For Task Name, type a name for the task.


Changing pool volume threshold1. In the Storage Systems tree, click Pools.2. From the names that appear on the Pools tab, click the pool with the

threshold that you want to change and click More Actions > Edit Pools.

3. In the Edit Pools window, complete the following items and then click Finish: Select Warning Threshold. For Warning Threshold, type a new threshold.

4. In the Confirm window, complete the following and then click Apply: For Task Name, type the task name.


The pool-VOL threshold is changed.

Changing pool volume names1. In the Storage Systems tree, click Pools.2. From the names that appear on the Pools tab, select the pool with the

name that you want to change and click More Actions > Edit Pools.3. In the Edit Pools window, select Pool Name.4. For Pool Name, type a name for the pool and click Finish.

5. In the Confirm window, complete the following and then click Apply: For Task Name, enter the task name.


Note: The possible range is shown below the item name.


Note: For item descriptions, including character limits, see Create Pools window on page B-16.





The pool-VOL name is changed.

Recovering pool volumes

1. In the Storage Systems tree, click Pools.2. From the names that appear on the Pools tab, select one or more pools

with volumes you want to recover and click More Actions > Restore Pools.

3. In the Restore Pools window, for Task Name, type a name and then click Apply.

The pool-VOL is recovered.

Deleting pool volumes1. In the Storage Systems tree, click Pools.2. From the names that appear on the Pools tab, select the pool-VOL that

you want to delete and click More Actions > Delete Pools.3. In the Delete Pools window, click Finish.4. In the Confirm window, complete the following and click Apply:

For Task Name, enter the task name.


The pool-VOL is deleted.

Managing virtual volumesYou can perform the following operations to manage V-VOLs:• Changing virtual volume names on page 6-9• Deleting virtual volumes on page 6-9

Within the resulting list on the Logical Devices window, you can do the following:• To select all pool-VOLs in the list, click Select All Pages.• To filter the rows, for Filter, click ON.• To specify the number of rows to show, click Options and make the

selection.

Note: The recovery time for pools depends on pool or V-VOL usage. Calculate roughly 20 minutes of recovery time for every 100 TB of pool or V-VOL usage. Recovery time also depends on system workload.

Note: For more information about character and symbol limits and default values, see Complete SIMs window on page B-33.



Changing virtual volume names1. In the Storage Systems tree, click Logical Devices.2. From the names that appear, select one or more V-VOL rows with names

that you want to change and then click More Actions > Edit LDEVs.3. In the Edit LDEVs window of the Edit LDEVs wizard, complete the

following: For LDEV Name, type a new name for the LDEV.

Character limit: 32 For Prefix, type alphanumeric characters.

Case-sensitive: Yes For Initial Number, type a number.

Limit: 9 digits4. Click Finish.5. In the Confirm window of the Edit LDEVs wizard, complete the

following and click Apply: For Task Name, type the task name.


The LDEV name is changed.

Deleting virtual volumes

1. In the Storage Systems tree, click Logical Devices.2. From the names that appear, select one or more V-VOL rows with V-

VOLS that you want to delete, click More Actions > Delete LDEVs.3. In the Delete LDEVs window, complete the following and then click

Apply: For Task Name, type the task name.

or Go to tasks window for status, select to open the Tasks window.

The V-VOL is deleted.


Note: You cannot make a V-VOL part of an SS pair. You must delete the pair before you can delete the V-VOL. For more information about deleting pairs, see Deleting pairs on page 5-12.




Switching off the storage system power and replacing the microcode

This topic explains how to maintain pairs when you switch off the storage system power and when you replace the microcode.

For more information, see:• Switching off the power supply on page 6-10• Replacing the microcode offline on page 6-10

Switching off the power supply

When you restore the power, SS’s behavior depends on the following:

If data in shared memory existed after switching off the power supply

If information in the shared memory exists after you have switched off the power supply, you can use the pools and pairs. However, since the storage system checks the status of the pools and the pool-VOLs, if the pool-VOLs are blocked at the time you switch off the power supply, the pool will be blocked and the status of the pairs changes to “PSUE”. When this occurs, you must restore the power and then recover the pools.

When you store snapshot data by consistency group, if you switch off the power supply before the status of all the pairs in a consistency group has changed completely, the snapshot data will not resume storing. When you restore the power, the status of some pairs may remain unchanged.

If information in shared memory is lost after switching off the power supply

If information in the shared memory is lost after switching off the power supply, the information about pools and pairs is also lost. If this occurs, complete the following:1. Restore the power.2. Recreate the pools and pairs.

For more information about creating pairs, see Creating pairs on page 5-5.For more information about creating pools, see Creating data pools on page 3-2.

Replacing the microcode offline

You usually replace the microcode online. If you replace it offline, the pool and pair information in shared memory is lost and you must recreate it. For example, when you need to change the configuration of shared memory.

Note: Stop the host I/O to the P-VOL before switching off the power supply for the storage system.

7

Copy-on-Write Snapshot troubleshooting 7–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Copy-on-Write Snapshottroubleshooting

This chapter provides Snapshot troubleshooting information.

□ General troubleshooting

□ Troubleshooting with Command Control Interface


7–2 Copy-on-Write Snapshot troubleshooting

General troubleshootingThe following table shows general SS troubleshooting information.

Problem Causes and solutions

You cannot install SS. Causes:• Shared memory for the V-VOL management area is not installed.• Shared memory is not set for the V-VOL management area.• Shared memory for the differential tables is not installed.Solutions:• Check if the shared memory for the V-VOL management area and the

differential tables is installed.• Check if the shared memory for the V-VOL management area is

correctly set.To check installation and settings, call the Support Center.

Pool information is not shown.

Cause: The pool is blocked.Solution: Recover the blocked pool. For more information, see Recovering a blocked pool workflow on page 7-6.

A pool is blocked. Cause: The pool-VOLs are blocked.Solution:1. Recover the blocked pool. For more information, see Recovering a

blocked pool workflow on page 7-6.2. Complete the SIMs. For more information, see Pool-related SIM entry

removal workflow on page 7-7.

Pool usage rate exceeds the threshold.

Causes:• An excess of SS data is being stored in the pool.• Capacity of the pool is insufficient.• Threshold of the pool is too low.Solutions:1. Complete one or more of the following:

Delete old or less important SS data to decrease the usage rate of the pool.

Add more pool-VOLs to increase the capacity of the pool.Note: You need unused volumes to add the pool-VOLs. If you do not have unused volume, you must create new volumes or call the Support Center to have them add the hard disks. The solution to this problem may take time.

Set a larger value for the pool threshold.2. Complete the SIMs.

For more information, see Pool-related SIM entry removal workflow on page 7-7.


Cannot add pool-VOLs. Causes:• The maximum number of pool-VOLs are set in the pool.

For more information about the maximum number of pool-VOLs, see Consistency group system requirements on page 2-2.

• Available pool management block in the V-VOL management area in the shared memory is insufficient.

• You did not following the Pool-VOL requirements.Solutions:• Add pool-VOLs to another pool.• Initialize the V-VOL management area.• Check pool-VOLs requirements. For more information, see Data pool

requirements and restrictions on page 2-4.

You cannot create the SS pairs.

Causes:• There are not enough differential tables to create the pairs.• The conditions to create the pair are not fulfilled.• The volumes that are specified to create the pair are in “SMPL (PD)”

status and are in the process of being deleted.Solutions:• Secure enough differential tables to create the pairs.• Fulfill the conditions to create the pair and try the pair creation again.• In the SI Pair Operation window, verify that the status of the

volume changes to SMPL, and then try the pair creation again.• Using the CCI, do the following:

a. Run the inqraid command.b. Verify that SS is not using the volume.c. Create the pair.

SS pairs are not shown in the volume list.

Causes:• The pairs are not created.• The filtering function is prohibiting you from showing the pairs.Solutions:• Create the pairs.• Open the Display Filter dialog box and change the settings.

An error occurred while restoring the pair.

Cause: A volume is blocked because a failure occurred in the hard disk drive.Solution: Delete the pair that is blocked, and call the Support Center.

A volume is blocked. Causes:• A failure occurred in two or more hard disk drives.• The breaker was turned off and then the power was restored.Solution: Contact the Hitachi Data Systems Support Center for assistance.




A problem occurred with the software application on the host server that is monitoring the volumes of SS pairs.

Cause: Access to the volume is rejected.Solution:1. On the host server, stop the monitoring software application.2. Change all pair statuses to “PSUS”.3. On the host server, start the monitoring software application.To check whether the host has access to pair volumes, view the P-VOL/S-VOL access columns. For more information about the pair status definitions, see Pair status definitions on page 6-2.

A V-VOL cannot be recognized correctly after you boot or reboot the host server or after you run the command for recognizing the device or V-VOL on the host server.

Cause: Access to the volume is rejected.Solution:1. On the host server, stop the monitoring software application.2. Change all pair statuses to “PSUS”.3. Do one of the following:

Reboot the host server. Run the command for recognizing the device or V-VOL on the

hose server.4. On the host server, start the monitoring software application.To check whether the host server has access to pair volumes, view the P-VOL/S-VOL access columns. For more information, see Pair status definitions on page 6-2.

When the host server tries to access the port, an error occurs and the host cannot access the port.

Cause: A port may go offline because access to a volume on another port is rejected.Solutions:• Retry the operation.• If you have installed and are running a software application on a host

server to monitor the volumes of SS pairs, stop the monitoring software application.

SN frequently times out. Causes:• The load on SN is too heavy and it cannot respond to the SVP.• The time-out period is not long enough.Solutions:• Retry the operation.• Verify the SN RMI time-out period.For more information about how to set RMI time-out period, see the Hitachi Storage Navigator User Guide.



Running the Pairsplit command on a consistency group terminates abnormally.

Causes:• All pairs in the consistency group are not in “PAIR” status. This may

result in rejection of the command, Timeout (Error code: EX_EWSTOT), or suspension of the pair (Error code: EX_EWSUSE).

• During the operation, you run the pairresync or pairsplit-S command on another pair or pairs in the consistency group. This can result in a timeout (Error code: EX_EWSTOT), or suspension of the pair (Error code: EX_EWSUSE)

Solutions:• Ensure all pairs in the consistency group are in “PAIR” status and run

the pairsplit command.• Perform only one operation on the pairs in a consistency group at one

time.

Running the Pairsplit command on a consistency group terminates abnormally when P-VOL shared with UR or TC.

Error code EX_EWSTOT is generated, and you cannot change the status of some SS pairs in a consistency group.Possible causes:• If you use an UR S-VOL as an SS P-VOL, the capacity of the journal

volumes for this UR pair is insufficient.• The SS license is invalid.• The SS pair volumes are blocked.• The SS pair is in a status for which you cannot run the pairsplit

command.For more information about the status that is required for CCI operations, see Statuses required for Command Control Interface pair operations on page A-2.

• The TC or UR pair status is not “PAIR”.Solution:1. Change all of the pairs to the “PAIR” status.2. From a command prompt, run the pairsplit command.

Restore pair operation terminates abnormally.

Causes:• The pair’s SS data is being stored per consistency group.• The P-VOL is also a P-VOL in another pair, and the SS data in the

second pair is stored per consistency group.

Creating consistency groups when host server is down or failed.

You can create a consistency group that does not contain pairs. However, if the host server is down or failed and you create pairs using the At-Time Split operation, the consistency group may be rejected.Solution:1. Find the consistency group number. Use the COW Snapshot or Pair

Operation window in SN.2. Create a pair specifying the consistency group number.

When you select the data pool, the pool capacity and other information shown in the Summary table is different than the information in the Primary Volumes tab.

Cause: The host is copying the pair and writing data.Solution: Wait until the pair is copied and the information shown in the Summary table and the Primary Volumes tab is the same.




Recovering from failure during pairresync -restore operationIf a failure occurs while you restore a pair and the pair status changes to “PSUE”, data in the P-VOL cannot be ensured. Establish consistency in the P-VOL.1. Delete the pair.2. Do one of the following:

Create a new pair. Resynchronize the pair.

3. Overwrite the P-VOL with backup data.

For more information about the cause and solution to errors when resynchronizing SS pairs that are in “PSUE” status, see General troubleshooting on page 7-2.

Recovering a terminated HP-UX host serverErrors can occur and the HP-UX host server can terminate if you use a volume in a paircreate command that has already been recognized by the host server as a V-VOL. You can recover the terminated HP-UX host server.1. Force the command process and its parent process to terminate.2. Create the SS pair. Ensure the emulation type is 0 (OPEN-0V) for both

the V-VOL and the VDEV for the V-VOL group.For more information about creating pairs, see Pair operations on page 5-2.

3. Split the pair.For more information about splitting pairs, see Splitting pairs on page 5-10.

4. Run the command for recognizing the device or V-VOL on the host server.

Recovering a blocked pool workflowWhen a pool is blocked, recover the pool.

Use the following workflow to recover the pool:1. Recover the pool-VOLs.

To recover a blocked pool-VOL, call the Support Center.

You cannot resynchronize an SS pair that is in “PSUE” status.

Cause: The host did not define the SS pair because the pair status changed to “PSUE” while the host was creating the pair.Solution:1. Delete all SS pairs associated with the P-VOL.2. Recreate the SS pairs.For more information about resolving this problem, see Recovering from failure during pairresync -restore operation on page 7-6.



2. Recover the pool.To recover the pool, do one of the following: Add additional pool-VOLs to the pool. Increase unused capacity by deleting the SS data from the pool. Lower the pool’s usage by deleting the pairs.

3. Recover the pairs by deleting the pairs.You must delete the pairs because the status of all pairs with SS data in a blocked pool changes to “PSUE”. To recover the pairs in this status, do the following:a. Delete the pair.b. Recreate the pair.

For more information about creating pairs, see Creating pairs on page 5-5.

4. Recover the V-VOLs.To do this, call the Support Center.

Pool-related SIM entry removal workflowUse the following workflow to remove Service Information Messages (SIM) entries from the storage system:1. Correct the problem related to the SIM. In the System Information/

Status window in SN, check the SIM and correct pool-related SIMs for the following: Reference code 601XXX: The pool usage rate exceeds the threshold. Reference code 602XXX: The pool is blocked.

2. Complete the SIM.The pool status is normal.

3. Change the SIM status to “Completed”.4. Complete the SIM.

For more information about completing SIMs, see Completing Service Information Messages on page 7-7.

Completing Service Information Messages1. In the Storage Systems tree, click Pools.2. From the names that appear on the Pools tab, click the pool that you

want to complete SIMs.3. On the Pools tab of the Pools window, select More Actions >

Complete SIMs.

Note: XXX indicates the pool ID.



4. In the Confirmation window, for Task Name, type a name for the task, and then click Apply.

The pool-related SIM is processed.

Troubleshooting with Command Control InterfaceTo identify the cause of errors while using CCI, you can use the following logs:• The log is shown in the CCI window.

For more information, see Identifying errors using the log on the CCI window on page 7-15.

• The CCI operation log file.For more information, see Identifying errors using the Command Control Interface operation log file on page 7-16

The following table lists the error codes for SSB1: B901, B9A8, B9A9, B9AD, B9AE, and 2E31. For more information about the error codes that are not described in this table, call the Support Center.


SSB2 CCI command Cause of error

9100 All commands You cannot run the command because the storage system did not perform user authentication.

9685 paircreate You cannot create the pair because of a shortage of pair tables.

9686 paircreate You cannot create the pair because of a shortage of differential tables.

9700 paircreate You cannot create the pair because the pool is not available.

9702 paircreate You cannot create the pair because a pair using a pool ID that is different from the specified pool ID exists in the specified P-VOL.

9703 paircreate You cannot create the pair because another HTI or SS S-VOL is using the volume you specified as the P-VOL.

9704 paircreate You cannot create the pair because another HTI or SS P-VOL is using the volume you specified as the S-VOL

9705 paircreate You cannot create the pair because another HTI or SS S-VOL is using the volume you specified as the S-VOL.

9706 paircreate You cannot create the pair because another SS pair is using the specified SS ID.

9707 paircreate You cannot create the pair because the capacity of the pair that you are trying to create exceeds the licensed capacity.

9718 All commands The command ends abnormally. You tried to use a command other than the paircreate command for the volume in the pair other than the SS pair.This error can also occur when you run the command with an unsupported parameter.


9719 All commands The command ends abnormally because the pair is in a status that the command does not accept, or because you ran the command with an unsupported parameter.

971A paircreate You cannot create the pair because you do not have a sufficient amount of shared memory.

971F pairresync -restore

The pair cannot be restored because the volume you specified as the P-VOL has an S-VOL Disable attribute.

9720 All commands An error occurred for one of the following reasons:• You specified an LDEV number for the P-VOL or S-VOL

that is not correct.• You specified a P-VOL or S-VOL that is not paired.• The P-VOL or S-VOL is specifying a pair that is not

ready for the specified operation.• You specified an MU number (SS ID) that is not

correct.• You specified an MU number (SS ID) that is already in

use.• You specified a pool that is unusable.• You have exceeded the license capacity.• The control tables for SS are running out.

9721 paircreate, pairsplit, pairresync, pairresync -restore

The command ends abnormally because SS or SI is not installed.

9723 All commands The command ends abnormally because additional shared memory (FCv2, TPF, Extension1) does not exist.

9724 All commands The command ends abnormally because additional shared memory (more than COW1) does not exist.

9725 All commands The command ends abnormally because the LDEV number of the volume you specified as the P-VOL exceeds the range.

9726 All commands The command ends abnormally because you specified the unmounted volume as the SS P-VOL.


The command ends abnormally because you specified a blocked volume as the SS P-VOL.


The command ends abnormally because you specified a volume that is in the process of being formatted as the SS P-VOL.


The command ends abnormally because you specified a volume as the SS P-VOL and that volume has an emulation type other than OPEN-V.




972A paircreate You cannot create the pair because the volume you specified as the SS P-VOL has the command device setting.

972C paircreate You cannot create the pair because the capacity of the volume you specified as the SS P-VOL exceeds the supported size (4TB).

972E paircreate You cannot create the pair because the capacity of the volume you specified as the SS S-VOL exceeds the supported size (4TB).

972F paircreate You cannot create the pair because you specified a V-VOL as the SS P-VOL.

9730 paircreate You cannot create the pair because you specified a pool-VOL as the SS P-VOL.

9731 pairresync -restore

You cannot create the pair because the SS P-VOL and TC P-VOL share the volume, and the status of the TC pair is not “PSUS” or “PSUE”.


You cannot restore the pair because the SS P-VOL and UR P-VOL share the volume, and the status of the UR pair is not “PSUS” or “PSUE”.


You cannot restore the pair because the SS P-VOL and TC S-VOL share the volume.


You cannot restore the pair because the SS P-VOL and UR S-VOL share the volume.

9735 paircreate You cannot create the pair because you specified UR’s journal volume as the SS P-VOL.


The command ends abnormally because the LUSE volumes you specified for the P-VOL and S-VOL do not have the same structure.

973A paircreate You cannot create the pair because you specified a volume with the VMA setting as the SS P-VOL.

973B All commands The command ends abnormally because the LDEV number of the volume you specified as the S-VOL exceeds the range.

973C All commands The command ends abnormally because you specified an unmounted volume as the SS S-VOL.

973D paircreate, pairsplit, pairresync, pairresync -restore

The command ends abnormally because you specified a blocked volume as the SS S-VOL.

973E paircreate, pairsplit, pairresync, pairresync -restore

The command ends abnormally because you specified a volume that is in process of being formatted as the SS S-VOL.



973F paircreate, pairsplit, pairresync, pairresync -restore

The command ends abnormally because you specified a volume whose emulation type is other than OPEN-V as the SS S-VOL.

9740 paircreate You cannot create the pair because the volume you specified as the SS S-VOL has the command device setting.

9742 paircreate You cannot create the pair because you specified an external volume as the SS S-VOL.

9745 paircreate You cannot create the pair because you specified a volume other than V-VOLs as the SS S-VOL.

9746 paircreate You cannot create the pair because you specified a pool-VOL as the SS S-VOL.

9747 paircreate You cannot create the pair because you specified a TC P-VOL as the SS S-VOL.

9748 paircreate You cannot create the pair because you specified TC S-VOL as the SS S-VOL.

9749 paircreate You cannot create the pair because you specified a UR data volume or journal volume in the intermediate site of 3DC cascading configuration as the SS S-VOL, the SS pair cannot be created.

974A paircreate You cannot create the pair because you specified a UR P-VOL as the SS S-VOL.

974B paircreate You cannot create the pair because you specified a UR S-VOL as the SS S-VOL.

974C paircreate You cannot create the pair because you specified a UR journal volume as the SS S-VOL.

974F All commands The command ends abnormally because the volume you specified as the S-VOL has an S-VOL Disable attribute.

9750 paircreate You cannot create the pair because you specified a volume with the VMA setting as the SS S-VOL.


The command ends abnormally because the Max LBA size for the volumes you specified as the SS P-VOL and S-VOL are different.


The command ends abnormally because the number of slots of the volumes you specified as the SS P-VOL and S-VOL are different.

9754 paircreate You cannot create the pair because you specified an HDP V-VOL as the SS S-VOL.

9756 All commands The command ends abnormally because you specified an SI reserved volume as the SS P-VOL.

9757 All commands The command ends abnormally because you specified a Volume Migration source volume as the SS P-VOL.For more information about using Volume Migration, call the Support Center.




9758 All commands The command ends abnormally because you specified a Volume Migration target volume as the SS P-VOL.For more information about using Volume Migration, call the Support Center.

9759 All commands The command ends abnormally because you specified a Volume Migration reserved volume as the SS P-VOL.For more information about using Volume Migration, call the Support Center.

975A All commands The command ends abnormally because you specified an SI P-VOL as the SS S-VOL.

975B All commands The command ends abnormally because you specified an SI S-VOL as the SS S-VOL.

975C All commands The command ends abnormally because you specified an SI reserved volume as the SS S-VOL.

975D All commands The command ends abnormally because you specified a Volume Migration source volume as the SS S-VOL.For more information about using Volume Migration, call the Support Center.

975E All commands The command ends abnormally because you specified a Volume Migration target volume as the SS S-VOL.For more information about using Volume Migration, call the Support Center.

975F All commands The command ends abnormally because you specified a Volume Migration reserved volume as the SS S-VOL.For more information about using Volume Migration, call the Support Center.

9763 paircreate The pair cannot be created for one of the following reasons:• The shared memory is not increased.• Initialization is in process.

976A paircreate You specified an unavailable parameter (unsupported parameter) in the command.

976C pairsplit SS data cannot be stored because you ran the command when the pair status was “PSUE”.

976E pairsplit SS data cannot be stored because the SS P-VOL and TC S-VOL share the volume, and the status of the TC pair is COPY.

976F pairsplit SS data cannot be stored because the SS P-VOL and UR S-VOL share the volume, the status of the UR pair is COPY.

9771 paircreate You cannot create the pair because you specified a UR delta resynchronization pair volume as the SS P-VOL.

9772 paircreate You cannot create the pair because you specified a UR delta resynchronization pair volume as the SS S-VOL.

9774 paircreate You cannot create the pair because the SS P-VOL and SI P-VOL share the volume, and the SI pair is using the MU number (SS ID) you specified for the SS pair.



9776 paircreate You cannot create the pair because the SS P-VOL and SI P-VOL share the volume, and the SI P-VOL you specified for the SS P-VOL has consistency group settings.

9777 paircreate You cannot create the pair because the SS P-VOL and SI S-VOL share the volume, and you specified MU number zero (0) for the SS P-VOL.

9778 paircreate You cannot create the pair because the SS P-VOL and SI S-VOL share the volume, and the SI S-VOL you specified for the SS P-VOL has consistency group settings.

977A paircreate, pairsplit

The command ends abnormally because the SS P-VOL and SI P-VOL share the volume, and the SI pair was in the process of resynchronization.

977B paircreate, pairsplit

The command ends abnormally because the SS P-VOL and SI S-VOL share the volume, and SI pair status is not “PSUS”.

977C pairresync -restore

The command ends abnormally because the SS P-VOL and SI P-VOL share the volume, and SI pair status is not “PSUS” or “PSUE”.

977D pairresync -restore

The command ends abnormally because the SS P-VOL and SI S-VOL share the volume, and SI pair status is not “PSUS”.

977E pairsplit SS data cannot be stored because the pool or the pool-VOL is blocked.


The pair cannot be restored for one of the following reasons:• The pair’s snapshot you want to restore is stored in a

consistency group.• The pair’s P-VOL you want to restore is used as the P-

VOL for another SS pair, and the SS data of the latter pair is stored in a consistency group.


The command ends abnormally because quorum disks are specified as P-VOLs of SS pairs.


The command ends abnormally because quorum disks are specified as S-VOLs of SS pairs.

978A paircreate The pair cannot be created using the consistency group number for one of the following reasons:• The specified consistency group number is in use for

SI.• The number of pairs has already exceeded the

maximum number of pairs that can be created for one consistency group.

• A pair that uses the same P-VOL exists already in the specified consistency group.




978B paircreate You cannot create the pair because the specified consistency group number is out of the range of the number that can be specified.

978C pairsplit SS data cannot be stored because the TC asynchronous pair status is other than “PSUS” or “PSUE” when SS (P-VOL) and TC asynchronous (S-VOL) share the volume.

978E paircreate You cannot create the pair for which you specified the consistency group. The P-VOL or S-VOL of the SI pair is already specified as the P-VOL of the SS pair.

9790 paircreate You cannot create the pair because you specified an HDP V-VOL that is undergoing capacity expansion as the SS P-VOL.

9793 paircreate You cannot create the pair because you specified an HDP V-VOL that is undergoing an Unmap command operation with system option mode 905 set to ON.


The command ends abnormally because you specified a volume without path definition as the SS P-VOL.


The command ends abnormally because you specified a volume without path definition as the SS S-VOL.

97A1 paircreate If you have already made the maximum number of SS pairs, you cannot create new pairs.

97A2 paircreate, pairsplit, pairresync, pairresync-restore

The command ends abnormally because the volume specified as the P-VOL uses two mirrors in a 3 UR data center configuration.

97A3 paircreate, pairsplit, pairresync, pairresync-restore

The command ends abnormally because the volume specified as the S-VOL uses two mirrors in a 3 UR data center configuration.

97A4 paircreate You cannot create the pair because the DP-VOL specified as the SS P-VOL is being initialized.

97A5 paircreate, pairsplit, pairresync, pairresync -restore

The command ends abnormally because you specified an external volume that is mapped for online data migration as the SS P-VOL.

97A6 paircreate, pairsplit, pairresync, pairresync -restore

The command ends abnormally because you specified an external volume that is mapped for online data migration as the SS S-VOL.

97C2 All commands The command ends abnormally because the specified MU number (SS ID) is outside the allowable range.



Identifying errors using the log on the CCI window1. Find the error code from the logs shown on the CCI window.

The following figure shows an example of a log shown on the CCI window:

2. Locate the SSB1 and SSB2 codes. In the previous figure the error codes appear to the right of SSB=. The last four digits to the left of the comma (,) are the SSB1 code

(B9E1). The last four digits to the right of the comma (,) are the SSB2 code

(B901).

97C4 paircreate The SS pair cannot be created because the specified pool is not a HTI or SS pool, or the specified pool does not exist.

97CB All Commands You cannot create the SS pair because the specified pool is an HTI pool.

97CE paircreate You cannot create the pair using the command. One of the following can be the reason:• You specified a consistency group number in HTI that

SS is using.• You specified a consistency group number in SS that

HTI is using.

97D6 paircreate, pairsplit, pairresync, pairresync -restore

The command ends abnormally because you specified an LDEV number other than the beginning of a LUSE volume as the SS P-VOL.

97D7 paircreate, pairsplit, pairresync, pairresync -restore

The command ends abnormally because you specified an LDEV number other than the beginning of a LUSE volume as the SS S-VOL.

B912 paircreate, pairsplit, pairresync

The pair operation fails because you specified the wrong S-VOL.

B9A7 All commands The consistency group information cannot be obtained because SS is not installed.


Figure 7-1 Example of a log shown on the CCI window

Note: You can view the description of the SSB1/SSB2 error code combination in the table that lists the error codes, above.



Identifying errors using the Command Control Interface operation log file

1. Open the CCI log file. The default location is /HORCM/log*/curlog/horcmlog_HOST/horcm.log, where: The asterisk (*) is the instance number. HOST is the host name.

2. Find the error code. An example error code string is:11:06:03-37897-10413- SSB = 0xB901,4A96

3. Locate the SSB1 and SSB2 codes. In the following figure: Error codes appear to the right of SSB=. The last four digits to the left of the comma (,) are the SSB1 code

(B901). The characters to the right of the comma (,) are the SSB2 code

(4A96).

Note: You can view the description of the SSB1/SSB2 error code combination in the table that lists the error codes, above.

A

Command Control Interface command reference A–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Command Control Interface commandreference

This appendix describes Command Control Interface (CCI) commands corresponding to actions in SN.

□ Command Control Interface commands for Storage Navigator operations

□ Storage Navigator and Command Control Interface pair status names

□ Statuses required for Command Control Interface pair operations


A–2 Command Control Interface command reference

Command Control Interface commands for Storage Navigator operations

The following table lists a mapping of the operations for logical device and pool that you can perform in SN to the CCI commands.

Storage Navigator and Command Control Interface pair status names

The CCI pair status name may be different than the SN pair status name. The following table shows a mapping of SN pair status names to CCI pair status names.

For more information about the pair status definitions, see Pair status definitions on page 6-2.

Statuses required for Command Control Interface pair operations

The pair must have a specific status to perform pair operations. The following table lists the CCI pair operations and the required status to perform the operation.

Item SN Operation CCI command

Logical Device Create LDEVs raidcom add ldev

Delete LDEVs raidcom delete ldev

Edit LDEVs raidcom modify ldev

Pool Create Pools raidcom add snap_pool

Expand Pool raidcom add snap_pool

Delete Pools raidcom delete pool

Edit Pools raidcom modify pool

Restore Pools raidcom modify pool

SN pair status name CCI pair status name

SMPL (is not shown) SMPL

COPY COPY

PAIR PAIR

PSUS SSUS

RCPY RCPY

PFUL PFUL

PFUS PFUS

PSUE PSUE

CCI pair operation Required status

paircreate SMPL

Command Control Interface command reference A–3Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

If you run a command for a pair with a status other than the one required, you can get mixed results. The following table lists the results for CCI commands that you run that have statuses other than those that are required.

paircreate –split PAIR/PFUL

pairsplit PAIR/PFUL

pairresync PSUS/PFUS, PSUE

pairresync -restore PSUS/PFUS

pairsplit -S PAIR/PFUL, PSUS/PFUS, PSUE


Status

CCI command

pair create

pair create-

splitpair split pair

resync

pair resync-restore

pair split-S pair split-E

SMPL Ok Ab Ab Ab Ab Np Ab

COPY Np Ab Ab Np Np Ab Ab

PAIR/PFUL Np Ok Ok Np Np Ok Ab

PFUS Ab Np Np Ok Ok Ok Ab

RCPY Np Ab Ab Np Np Ab Ab

PSUE Ab Ab Ab Ok* Ab Ok Np

Ok: Ends normallyNp: Not performed but ends normallyAb: The command is rejected, ends abnormally* If you run the pairresync to a pair in “PSUE” status because you cannot reserve shared memory for the S-VOL management area, the command is rejected and ends abnormally.


A–4 Command Control Interface command reference

B

Copy-on-Write Snapshot GUI reference B–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Copy-on-Write Snapshot GUIreference

This appendix describes SS windows and dialog boxes.

□ Pools window

□ Selected pool volume window

□ Create Pools wizard

□ Expand Pool wizard

□ Edit Pools wizard

□ Delete Pools wizard

□ Restore Pools window

□ Complete SIMs window

□ Select Pool window

□ Select Pool Volumes window

□ Pool Property window

□ Create Pairs wizard


B–2 Copy-on-Write Snapshot GUI reference

Pools windowUse the Pools window to view information about pools in your system.

You can do the following from this window:• Copy-on-Write Snapshot installation and configuration on page 3-1• Copy-on-Write Snapshot monitoring and maintenance on page 6-1• Increasing data pool volume capacity on page 6-6• Changing pool volume threshold on page 6-7• Changing pool volume names on page 6-7• Recovering pool volumes on page 6-8• Deleting pool volumes on page 6-8

For more information, see:• Summary table on page B-3• Pools tab on page B-3


Summary table

Pools tab

Use this tab of the Pools window to view specific pool information.

Item Description

Pool Capacity* The capacity for the pool.• Used/Total

For SS: The SS pool capacity (used/total).For each value, if Pool Capacity Estimated

Configurable is zero, is shown.• Estimated Configurable

For SS: The remaining physical pool capacity that is configurable in SS.

V-VOL Capacity* Shows information about DP-VOL capacity.For SS, a hyphen (-) is shown.

Licensed Capacity (Used/Licensed)

For SS, the total licensed system capacity for SI and SS, including the capacities of LDEVs and other resources assigned to other users. The value shown for Licensed Capacity Used can differ from the value shown for Pool Capacity Total.

Number of Pools The total number of pools that SS, HDP, HDPz, HDT, and Dynamic Tiering for Mainframe (HDTz) are using.

Edit Tiering Policies button Click to open the Edit Tiering Policies window.For more information about the tasks you can perform from this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

* The total value of Total for Capacity for each pool type in the Pools window and the total Used capacity for Pool Capacity in the Summary table are almost the same, but small differences might occur.

Item Description

Pool Name (ID) The pool’s name and identifier. Clicking this link shows additional pool information.



Status Information about the pool status.Values:

• Normal: The pool is in a normal status and is accessible.

• Warning: The pool-VOL in the pool is blocked.

• Exceeded Threshold: The pool’s used capacity exceeds the pool threshold.

• Shrinking: Reducing the pool-VOL.

• Blocked: The pool is full, or an error occurred in the pool, therefore the pool is blocked and cannot be used. If the pool is in both Warning and Blocked status, only Blocked is shown.

Number of pool volumes The number of pool-VOLs.

Number of V-VOLS The number of V-VOLs associated with the pool. For SS, a hyphen (-) is shown.

Number of Primary VOLs The number of SS P-VOLs. If you are not using the pool for SS, a hyphen (-) is shown.

RAID Level The RAID level.If multiple RAID levels exist in a pool, Mixed is shown.

Capacity Information about pool capacity.Values:• Total: The pool’s total capacity

Unit of capacity: Click Option to select the unit of capacity.One block equals 512 bytes and one page equals 256 kilobytes in SS pool capacity.

• Used: The amount of pool capacity that is used.• Used (%): The percentage of pool capacity that is

used.If you clicked Option to change the unit of capacity to Cylinder, a hyphen (-) is shown.

User-Defined Threshold(%)

Information about the pool threshold.Values:• Warning: Warning threshold is shown.• Depletion: Depletion threshold is shown.

For SS, a hyphen (-) is shown.Caution: You must define both user-defined thresholds. Defining only one of the user-defined pool thresholds enables the system threshold (fixed at 80%). If the pool’s used capacity exceeds the user-defined threshold, SIM code 620XXX is reported. You cannot set the system threshold.

Item Description


Subscription (%) Shows the following information about the pool’s subscription:• Current: Current subscription.

For SS, a hyphen (-) is shown.• Limit: Subscription limit.

For SS, a hyphen (-) is shown.

Pool Type Shows the type of pool.Value: COW Snapshot

Drive Type/RPM The pool’s hard disk drive type and RPM.If multiple drive types or RPMs exist in a pool, Mixed is shown.(External LDEVs) External Storage and the value of the external LDEV tier rank is shown.

Tier Management Shows whether HDT is enabled or disabled.For SS, a hyphen (-) is shown.

CLPR The CLPR (cache logical partition) set for the pool-VOL. For pools other than for SS, a hyphen (-) is shown.

Shrinkable Shows whether you can delete the pool-VOL.For SS, a hyphen (-) is shown because its pool is not shrinkable.

Monitoring Mode The monitoring mode set for the pool, Continuous Mode or Period Mode.

Monitoring Status The status of pool monitoring.Conditions:• In Progress: Monitoring is being performed.• During Computation: Calculating is being processed.If a condition is not present, a hyphen (-) is shown.

Recent Monitor Data The latest monitoring data.Values:• If monitoring data exists, the monitoring period of time

is shown. Example: 2010/11/15 00:00 - 2010/11/15 23:59

• If monitoring data is being obtained, only the starting time is shown.Example: 2010/11/15 00:00 -

• If the latest monitoring data does not exist, a hyphen (-) is shown.

Pool Management Task The pool management task being performed on the pool.For SS and HTI pools, a hyphen (-) is shown.

Recent Relocation Progress The rate for recent tier relocation processing.

Mixable* Shows whether pool-VOLs whose RAID levels are different can coexist in the pool.For SS, a hyphen (-) is shown.

Create Pools button Click to open the Create Pools window.

Item Description



Selected pool volume windowUse the selected pool volume window to view information about the pool-VOL you have selected and its associated P-VOL.

The following image shows this window.

Create LDEVs button Click to open the Create LDEVs window of the Create LDEVs wizard.For more information about the tasks you can perform from this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

Expand Pool button Click to open the Expand Pool window.

More Actions > Delete Pools

Click to open the Delete Pools window.

More Actions > Restore Pools

Click to open the Restore Pools window.

More Actions > Edit Pools Click to open the Edit Pools window.

More Actions > Monitor Pools

Click to open the Monitor Pools window.

More Actions > Stop Monitoring Pools

Click to open the Stop Monitoring Pools window.

More Actions > Start Tier Relocation

Click to open the Start Tier Relocation window.

More Actions > Stop Tier Relocation

Click to open the Stop Tier Relocation window.

More Actions > Complete SIMs

Click to open the Complete SIMs window.

More Actions > View Tier Properties

(HDT or HDTz only) Click to open the View Tier Properties window.

More Actions > View Pool Management Status

Click to open the View Pool Management Status window.

More Actions > Export Click to open a window to export table information.

More Actions > Tier relocation log

Click to open the download screen for tier relocation operation results.

* Does not appear in the default view.

Item Description


Summary table

Item Description

Status Shows the following information about the pool status:Values:

• Normal: The pool is in a normal status and is accessible.

• Warning: The pool-VOL is blocked.

• Exceeded Threshold: The pool’s used capacity exceeds the pool threshold.


• Blocked: The pool is full, or an error occurred in the pool, therefore the pool is blocked and cannot be used. If the pool is in both Warning and Blocked status, only Blocked is shown.

Pool Name (ID) The pool’s name and identifier.

Pool VOL with System Area (Name)

The pool’s LDEV ID and LDEV name.For SS, a hyphen (-) is shown.

Pool Type The pool’s type.Value: COW Snapshot



RAID Level The pool’s RAID level.For multiple RAID levels in a pool, Mixed is shown.

Drive Type/RPM The pool’s data drive type and RPM.For multiple Drive Type/RPMs in a pool, Mixed is shown.(External LDEVs) External Storage and the value of the external LDEV tier rank is shown.

CLPR The CLPR configured in SS pool-VOL in ID:CLPR name form.For pool-VOLs other than for SS, a hyphen (-) is shown.

Cache Mode Shows whether cache mode is enabled or disabled.For non-external volume configurations, a hyphen (-) is shown.

Number of Pool VOLs The number of pool-VOLs set for the pool, and the maximum number of pool-VOLs that you can set.

Number of V-VOLs The number of V-VOLs associated with the pool.For SS, a hyphen (-) is shown.

Number of Primary VOLs The number of SS P-VOLs.For pools other than for SS, a hyphen (-) is shown.

Pool Capacity (Used/Total) The used and total pool capacity. If the pool consists of multiple pool-VOLs, the sum of their capacities is shown for Total.

V-VOL Capacity (Used/Total)

The used and total V-VOL capacity. For SS, a hyphen (-) is shown.

Subscription (Current/Limit)

The subscription rate.For SS, a hyphen (-) is shown.

User-Defined Threshold (Warning/Depletion)

Information about the pool threshold.Values: Warning and DepletionFor SS, a hyphen (-) indicates a depletion.

Tier Management Shows whether HDT is enabled or disabled. For SS, a hyphen (-) is shown.

Cycle Time The cycle of performance monitoring and tier relocation. If HDT is disabled, a hyphen (-) is shown.

Monitoring Period The starting and ending of performance monitoring times. If HDT is disabled, a hyphen (-) is shown.

Monitoring Mode The monitoring mode set for the pool, Continuous Mode or Period Mode If HDT or HDTz is disabled, a hyphen (-) is shown.

Monitoring Status Pool monitoring status. If the monitoring is being performed, In Progress is shown; otherwise a hyphen (-) is shown.

Item Description


Pool Volumes tab

Use the Pool Volumes tab to view specific pool-VOL information.

Recent Monitor Data The latest monitoring data is shown, as follows:• If the monitoring data exists, the monitoring period of

time is shown.Example: 2010/11/15 00:00 - 2010/11/15 23:59

• If the monitoring data is being obtained, only the starting time is shown.Example: 2010/11/15 00:00 -

• If the latest monitoring data does not exist, a hyphen (-) is shown.

Pool Management Task The pool management task being performed on the pool.For SS, a hyphen (-) is shown.

Relocation Result The status of the tier relocation processing.For pools other than for HDT or HDTz, a hyphen (-) is shown.

Item Description

Item Description

LDEV ID The pool-VOL’s LDEV identifier.

LDEV Name The pool-VOL’s LDEV name.

Status Shows the following information about the pool status.Values:

• Normal: The pool-VOL is in normal status and is accessible.


• Blocked: The pool-VOL is blocked and cannot be accessed.

Parity Group ID The parity group ID.

Usable Capacity Shows available capacity of page boundaries in a pool-VOL by the specified unit. For a pool-VOL with system area, the shown capacity does not include the capacity of the management areaFor HDP, HDT, and SS pools, if you change the unit of capacity to Cylinder, a hyphen (-) is shown.

RAID Level The pool-VOL’s RAID level.If multiple RAID levels exist in a pool, Mixed is shown.

Emulation Type The pool-VOL’s emulation type.

Drive Type/RPM The pool-VOL’s data drive type and RPM.(External LDEVs) External Storage and the value of the external LDEV tier rank is shown.



Virtual Volumes tab

This tab is shown for all pools except HTI and SS pools.

Tier ID The tier ID. For SS, a hyphen (-) is shown.

Provisioning Type The pool-VOL LDEV’s provisioning type.• Basic: Internal volume• External: External volume

Shrinkable Shows whether you can delete the pool-VOL.For SS, a hyphen (-) is shown.

Resource Group Name (ID) The resource group name and identifier of the LDEV. The ID is in parentheses.

Expand Pool Click to open the Expand Pool window.

Shrink Pool Click to open the Shrink Pool window.

Stop Shrinking Pools Click to open the Stop Shrinking Pools window.

More Actions > Edit External LDEV Tier Rank

Click to open the Edit External LDEV Tier Rank window.For more information about the tasks you can perform from this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.You can performs tasks on HDP, HDPz, HDT, and HDTz pools.

More Actions > Export Click to open the window to export table information.

Item Description

Item Description

LDEV ID The LDEV’s identifier.

LDEV Name The LDEV’s name.


Status The LDEV’s status.Values:

• Normal: The P-VOL’s LDEV is in normal status and is accessible.

• Blocked: The P-VOL’s LDEV is blocked. The host cannot access the volume.

• Warning: The host has detected a problem in the P-VOL LDEV.

• Formatting: The host is formatting the P-VOL’s LDEV.

• Preparing Quick Format: The host is preparing to quick format the P-VOL’s LDEV.

• Quick Formatting: The host is quick formatting the P-VOL’s LDEV.

• Correction Access: The host is correcting the access attribute for the P-VOL’s LDEV.

• Copying: The host is copying data in the P-VOL’s LDEV.

• Read Only: The P-VOL’s LDEV data is read-only. The host cannot write data.

• Shredding: The host is shredding the P-VOL’s LDEV data.

• -: The P-VOL’s LDEV has a status other than the ones listed.

Emulation Type The LDEV’s emulation type.

Capacity - Total The total V-VOL capacity.Note: This amount might be larger than the Capacity - Used amount.

Capacity - Used The V-VOL used capacity, which is the rounded-up amount on each page.If the emulation type is 3390-A, this amount includes the control cylinder capacity (7 Cyl is required per 1,113 Cyl).

Capacity - Used(%) The V-VOL usage level.

Number of Paths The number of alternate paths.

CLPR The CLPR in the format, ID:CLPR.

Item Description



Tiering Policy The tiering policy name and ID.Values:• All(0): The policy for which you are using all of the

tiers in the pool.• Level1(1) - Level31(31): The user definition

policy for any V-VOL Level1 to Level31 tier.A hyphen (-) is shown if the V-VOL is not an HDT or HDTz V-VOL.

Tiering Policy - New Page Assignment Tier

The new page assignment tier.Values: High, Middle, or LowA hyphen (-) is shown if the V-VOL is not an HDT or HDTz V-VOL.

Tier Relocation The tier relocation status.Values: Enabled or DisabledA hyphen (-) is shown if the V-VOL is not an HDT or HDTz V-VOL.

Relocation Priority The tier relocation priority.Values:• Prioritized: You have set the V-VOL priority.• Blank: You have not set the V-VOL priority.A hyphen (-) is shown if the tier relocation functionality is disabled or if the V-VOL is not an HDT or HDTz V-VOL.

Pool Management Task The pool management task being performed on the pool.For SS and HTI pools, a hyphen (-) is shown.

V-VOL Management Task The V-VOL management task that you are performing.Values:• Reclaiming Zero Pages: You are reclaiming zero

pages.• Waiting for Zero Page Reclaiming: The storage

system has not started the process to reclaim zero pages.

A hyphen (-) is shown if you are not performing a V-VOL management task.

Page Status Shows the status of reclaiming zero pages. If you are reclaiming zero pages, Reclaiming Zero Pages is shown. If not, this item is blank.

Attribute The LDEV’s attribute.Value: TSE is shown if the volume is a TSE-VOL.A hyphen (-) is shown if you have not defined the volume.

Resource Group Name (ID) The resource group names and identifiers of the LDEV. The ID is provided in parentheses.

Item Description


Create LDEVs button Click to open the Create LDEVs window of the Create LDEVs wizard.For more information about the tasks you can perform from this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

Add LUN Paths button Click to open the Add LUN Paths window.For more information about the tasks you can perform from this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.This item is not available if you select Dynamic Provisioning for Mainframe or Dynamic Tiering for Mainframe as the Pool Type.

Expand V-VOLs button Click to open the Expand V-VOLs window.For more information about the tasks you can perform using this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

More Actions > Format LDEVs Click to open the Format LDEVs window.For more information about the tasks you can perform using this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

More Actions > Delete LDEVs Click to open the Delete LDEVs window.

More Actions > Shred LDEVs Click to open the Shred LDEVs window.

More Actions > Delete LUN Paths

Click to open the Delete LUN Paths window.For more information about the tasks you can perform using this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

More Actions > Block LDEVs Click to open the Block LDEVs window.For more information about this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

More Actions > Restore LDEVs

Click to open the Restore LDEVs window.For more information about this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

More Actions > Edit LDEVs Click to open the Edit LDEVs window.

More Actions > Reclaim Zero Pages

Click to open the Reclaim Zero Pages window.For more information about this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

More Actions > Stop Reclaiming Zero Pages

Click to open the Stop Reclaiming Zero Pages window.For more information about this window, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

More Actions > View Tier Properties

Click to open the View Tier Properties window.

More Actions > Export Click to open the window to export table information.

Item Description



Primary Volumes tab

Use the Primary Volumes tab to view specific P-VOL information for an LDEV.

Item Description

LDEV ID The P-VOL’s LDEV identifier.

LDEV Name The P-VOL’s LDEV name.


Create Pools wizardUse this wizard to create pools. For more information about creating pools, see Creating data pools on page 3-2.

Status The LDEV’s status.Values:

• Normal: The P-VOL’s LDEV is in normal status and is accessible.

• Blocked: The P-VOL’s LDEV is blocked. The host cannot access the volume.

• Warning: The host has detected a problem in the P-VOL LDEV.

• Formatting: The host is formatting the P-VOL’s LDEV.

• Preparing Quick Format: The host is preparing to quick format the P-VOL’s LDEV.

• Quick Formatting: The host is quick formatting the P-VOL’s LDEV.

• Correction Access: The host is correcting the access attribute for the P-VOL’s LDEV.

• Copying: The host is copying data in the P-VOL’s LDEV.

• Read Only: The P-VOL’s LDEV data is read-only. The host cannot write data.

• Shredding: The host is shredding the P-VOL’s LDEV data.

• -: The P-VOL’s LDEV has a status other than the ones listed.


Used Pool Capacity The pool’s used capacity.

Pool Usage (%) The ratio of the pool’s used capacity to its full capacity.

Number of Paths The number of alternate paths.

CLPR The CLPR in the format, ID:CLPR.

Export button Click to open the Export window to output P-VOL information to a file.

Item Description



Create Pools window


Setting items

In the following table, items that are marked with an asterisk (*) require configuration.

Item Description

Pool Type* The pool’s type.Value: COW Snapshot



System Type The system type.Value: OpenYou can only select Open if the pool type is COW Snapshot.

Multi-Tier Pool HDP/HDT only.

Drive Type/RPM* The pool-VOL’s hard disk drive type and RPM.Values:• Mixable: This value is shown if the volume is nn HDT

volume.• External Storage: This value is shown if the volume

is an external volume.

RAID Level* The pool-VOL’s RAID level.Values:• Hyphen (-): If you select External Storage as the

Drive Type/RPM, a hyphen (-) is shown.• Mixable: This value is shown if the volume is an HDP/

HDT volume.

Select Pool VOLs button* Click to open the Select Pool Volumes window. You must select a pool-VOL.

Total Selected Pool Volumes

The total number of the selected pool-VOLs.

Total Selected Capacity The total capacity of the selected pool-VOLs.

Pool Name* Set the pool name:• Prefix: Type the alphanumeric characters, which are

fixed characters before the pool name.Case-sensitive: Yes

• Initial Number: Type the initial number following the prefix name.Limit: 9 digits

Character limit: 32

Initial Pool ID Entering the registered pool ID, adds the smallest available pool ID automatically registered among the subsequent pool ID that you entered.Default: The smallest available numberLimit: 0 to 127If an available pool ID does not exist, this item is blank.

Subscription Limit (%) The pool’s subscription limit.For SS, this item is unavailable.

Warning Threshold The pool’s warning threshold.Limit: 20% to 95%, in 5% incrementsDefault: 80%

Depletion Threshold For SS, this item is unavailable.

Tier Management HDP/HDT only.

Monitoring Mode HDP/HDT only.

Item Description


Selected pools table

Buffer Space for New page assignment (%)

HDP/HDT only.

Buffer Space for Tier relocation (%)

HDP/HDT only.

Item Description

Item Description

Pool Name (ID) The pool’s nickname and identifier.



RAID Level The pool’s RAID level.If multiple RAID levels exist in a pool, Mixed is shown.

Capacity The pool’s maximum capacity.


Drive Type/RPM The data drive type and RPM.If multiple types of drives exist in a pool, Mixed is shown.(External LDEVs) External Storage and the value of the external LDEV tier rank is shown.

User-Defined Threshold (%)

Information about the pool threshold.Values:• Warning: The warning threshold is shown.• Depletion: The depletion threshold is shown.


Subscription Limit (%) The pool’s subscription limit.For SS, a hyphen (-) is shown.

Number of Pool VOLs The number of pool-VOLs.



HDP/HDT only.


HDP/HDT only.

Detail When you select a line, the Pool Properties window opens. You must select a line. If you do not select a line or if you select multiple lines, an error window opens.

Remove Deletes the pool selected in the Selected Pools window. You must select a line. If you do not select a line, an error window opens.

Item Description


Confirm window

Create Pools table

Item Description


RAID Level The pool’s RAID level.

Capacity The pool’s capacity.

Pool Type The type of pool.Value: COW Snapshot

Drive Type/RPM The data drive type and RPM.(External LDEVs) External Storage and the value of the external LDEV tier rank is shown.



For SS pools, a hyphen (-) is shown.



Expand Pool wizardThe Expand Pool wizard consists of the Expand Pool window and the Confirm window.

Use the Expand Pool wizard to increase data pool capacity. For more information about increasing data pool capacity, see Increasing data pool volume capacity on page 6-6.

Expand Pool windowThe Expand Pool window is the first window in the Expand Pool wizard. This window shows the Pool Volume Selection area.

Subscription Limit (%) The pool’s subscription limit.For SS, a hyphen (-) is shown.




HDP/HDT only.


HDP/HDT only.


Total The total number of pools.

Item Description


Pool Volume Selection area

Use the Pool Volume Selection area of the Expand Pool window to define the drive type and RAID level for LDEVs you are adding to increase the pool capacity.

Item Description

Drive Type/RPM The drive type and RPM of the selected pool.Values:• Mixable• External Storage: Shows if the volume is an external

volume.

RAID Level For SS whose RAID level is fixed, this item is unavailable.

Select Pool VOLs button Click to open the Select Pool Volumes window.

Total Selected Pool Volumes

The total number of selected pool-VOLs.

Total Selected Capacity The total capacity of the selected pool-VOLs.



Confirm windowThe Confirm window is the second window in the Expand Pool wizard. This window shows the Selected Pool table and the Selected Pool Volumes table.

Use this window to do the following:1. Type a name for the task.2. Confirm the settings in the list.3. Add the task to the Tasks queue so that the operation is performed.

Selected Pool table

Use the Selected Pool table to view the list of pools that are selected.

Selected Pool Volumes table

Use the Selected Pool Volumes table to view the list of pool-VOLs that are selected.

Item Description



Edit Pools wizardThe Edit Pools wizard consists of the Edit Pools window and the Confirm window.

Use the Edit Pools wizard to change a pool name and threshold. For more information about editing pools, see:• Changing pool volume names on page 6-7• Changing pool volume threshold on page 6-7

Edit Pools windowThe Edit Pools window is the first window in the Edit Pools wizard. This window shows the Setting items area.

Item Description



Capacity The pool-VOLs's capacity.

Parity Group ID The pool-VOL’s parity group ID.

RAID Level Does not apply to SS, whose RAID level is fixed.

Drive Type/RPM The hard disk drive type and RPM.(External LDEVs) External Storage and the value of the external LDEV tier rank is shown.


Total The total number of pool-VOLs.



Setting items area

Use this area of the Edit Pools window to edit the pool’s properties.

Item Description

Multi-Tier Pool For SS, this item is unavailable.

Options for Multi-Tier Pool For SS, this item is unavailable.

Subscription Limit For SS, this item is unavailable.


Confirm windowThe Confirm window is the second window in the Edit Pools wizard. This window shows the Selected Pools table.

Use this window to do the following:1. Type a name for the task.2. Confirm the settings in the list.3. Add the task to the Tasks queue so that the operation is performed.

The following image shows the Selected Pools table.

Pool Name Select the Pool Name check box to enter the pool name:If the check box is not selected, the setting is not applied.• Prefix: Type the alphanumeric characters, which are

fixed characters before the pool name.Case-sensitive: Yes

• Initial Number: Type the initial number for the pool name.Limit: 9 digits

Character limit: 32Default: When you select one pool, for Prefix, the pool name is shown.When multiple pools are selected, the numbers ranging from the specified Initial Number to the maximum number of the same digits are automatically set to the pool name.Examples:• If you set the Initial Number at 1, a number from 1

to 9 is automatically added to each pool name.• If you set the Initial Number at 08, a number from

08 to 99 is added to each pool name.• If you set the Initial Number to 098, a number from

098 to 999 is added to each pool name.

Warning Threshold Information about the pool’s warning threshold.Select and type the threshold value.Minimum threshold: Pool usage rate plus one percent (1%)Maximum threshold: 95 percent (95%)

Depletion Threshold For SS, this item is unavailable.

Item Description



Selected Pools table

Use the Selected Pools table to view the list of pools that are selected.

The following tables provides descriptions of the items in the Selected Pools table.

Item Description


RAID Level The RAID level.If multiple RAID levels exist in a pool, Mixed is shown.

Capacity The pool capacity.



Delete Pools wizardThe Delete Pools wizard consists of the Delete Pools window and the Confirm window.

Use the Delete Pools wizard to delete a pool-VOL and make the pool-VOL available for other use. For more information about deleting pools, see Deleting pool volumes on page 6-8.

Delete Pools windowThe Delete Pools window is the first window in the Delete Pools wizard. This window shows the Selected Pools table.

You can do the following from this window:• Go to the next page where you can shred the LDEVs for the selected

pool. To do this, click Next.• Confirm the deletion. Click Finish.

The following image shows the Delete Pools window of the Delete Pools wizard.

Drive Type/RPM The data drive type and RPM.If multiple types of drives exist in a pool, Mixed is shown.(External LDEVs) External Storage and the value of the external LDEV tier rank is shown.


Information about the pool threshold.For SS, a hyphen (-) is shown.

Subscription Limit (%) The subscription limit. For SS, a hyphen (-) is shown.


Multi-Tier Pool HDT information.For SS, this item is unavailable.


For SS, this item is unavailable.


For SS, this item is unavailable.


Item Description




Use this table on the Delete Pools window to view the list of pools that are selected.

Item Description



Capacity The pool capacity.For LUSE, shows the LUSE capacity.


Drive Type/RPM The pool’s hard disk drive type and RPM.If multiple types of drives exist in a pool, Mixed is shown.(External LDEVs) External Storage and the value of the external LDEV tier rank is shown.





Confirm windowThe Confirm window is the second window in the Delete Pools wizard. This window shows the Selected Pools table.

Use this window to do the following:1. Type a name for the task.2. Confirm the settings in the list.

3. Add the task to the Tasks queue so that the operation is performed.


Use this table on the Confirm window of the Delete Pools wizard to view the list of pools that are selected.



Item Description

Note: Ensure that you want to delete the listed pool-VOLs.



Restore Pools windowUse the Restore Pools window to recover a blocked pool. For more information about recovering pools, see Recovering pool volumes on page 6-8.

This window shows the Selected Pools table.

Item Description



Capacity The pool capacity.In LUSE, shows the LUSE capacity.


Drive Type/RPM The hard disk drive type and RPM.If multiple types of drives exist in a pool, Mixed is shown.(External LDEVs) External Storage and the value of the external LDEV tier rank is shown.

User-Defined Threshold (%) Information about the pool threshold.For SS, a hyphen (-) is shown.


Detail button Select a line and click to open the Pool Properties window.




Use the Selected Pools table to view the list of pools that are selected.

Complete SIMs windowUse the Complete SIMs window to remove the SIM entry from the system. For more information about removing SIMs, see Pool-related SIM entry removal workflow on page 7-7.

This window shows the Setting items area.

Item Description



Capacity The pool capacity.If the pool is blocked and the pool-VOLs that belong to the pool cannot be identified, 0 is shown.


Drive Type/RPM The hard disk drive type and RPM.If multiple types of drives exist in a pool, Mixed is shown.(External LDEVs) External Storage and the value of the external LDEV tier rank is shown.

User-Defined Threshold (%) Information about the pool threshold.For SS, a hyphen (-) is shown.




Setting items area

Use the Setting items area of the Complete SIMs window to type the task name and add the task to the Tasks queue so that the operation is performed.

Select Pool window

Available Pools table

Item Description

Task Name The task name.Character and symbol limit: 32Allowable characters and symbols: All alphanumeric except / : , ; * ? ” < > |Case-sensitive: YesDefault: date-window name

Item Description



Capacity The pool’s capacity.Values:• Total: The total pool capacity.• Used: The amount of pool capacity that is used.• Used (%): The percentage of pool capacity that is

used.


Select Pool Volumes window



Information about the pool threshold.

CLPR The ID and name of the CLPR in the CLPR-name format.

Item Description



Available Pool Volumes table

The following table shows descriptions of the items in the Available Pool Volumes table.

Item Description

LDEV ID The LDEV’s identifier.


Capacity The pool-VOL capacity.


RAID Level The RAID level.

Drive Type/RPM The hard disk drive type and RPM.(External LDEVs) External Storage is shown.


Provisioning Type The LDEV type.Values:• Basic: Internal volume• External: Shows if the LDEV is an external volume.


The External LDEV Tier Rank specifies the external LDEV tier rank. If an external LDEV does not exists in the Available Pool Volumes table or Selected Pool Volumes table, you cannot select the tier rank.

Selected Pool Volumes table

You can add a maximum of 1,024 volumes, including volumes that already exist in the pool.

For more information about the maximum number of volumes, see Consistency group system requirements on page 2-2.

CLPR Shows cache logical partition.

Cache Mode Shows whether the cache mode is enabled or disabled.For non-external volumes, a hyphen (-) is shown.


Item Description

Item Description

LDEV ID The LDEVs identifier.




Capacity The pool-VOL capacity.


RAID Level Show the RAID level.

Drive Type/RPM The data drive type and RPM.(External LDEVs) External Storage is shown.

External LDEV Tier Rank The external volume tier rank.For non-external volume, a hyphen (-) is shown.


Provisioning Type The LDEV type.Values:• Basic: Internal volume• External: External volume

CLPR Shows cache logical partition.

Cache Mode Shows the cache mode.Values: Enabled or DisabledFor non-external volumes, a hyphen (-) is shown.


Item Description


Pool Property window

Pool Properties table

Item Description



Capacity The pool capacity by the specified unit.

User-Defined Threshold (Warning/Depletion)

Information about the pool threshold.Values: Warning and Depletion

Subscription Limit The subscription limit.For SS, a hyphen (-) is shown.

RAID Level The RAID level.

CLPR Shows the CLPR configured in SS pool-VOL in ID:CLPR name form.For pool-VOLs other than for SS, a hyphen (-) is shown.



Pool Volumes table

Create Pairs wizardThe Create Pairs wizard consists of the Create Pairs window. Use the Create Pairs wizard in this window to create pairs.

Select Pair Configuration window

Pool VOL with System Area (Name) The pool-VOL’s LDEV ID and LDEV name that contains the pool’s management area.For SS, a hyphen (-) is shown.

Item Description

Item Description



Capacity The pool-VOL capacity by the specified unit.

Parity Group ID The pool-VOL’s parity group ID.

RAID Level The pool-VOL’s RAID level.



Provisioning Type The pool-VOL’s provisioning type.Values:• Basic: Internal volume• External: External volume



Select Primary Volumes window

Item Description

Copy Type The copy type.Values:• ShadowImage• ShadowImage for Mainframe• Thin Image• COW Snapshot

Emulation Type The emulation type.Value: OPEN-VFor HTI or SS, you can only specify OPEN-V.

Pair Topology Type This item is shown only when you specify SI as the copy type.Specify the SI pair configuration. If you specify the existing pair to open this window, the pair topology type is shown as the pair configuration.The checkbox is:• Not selected, but available: You can set a pair

configuration.• Selected, but not available: The SI pair exists.• Neither selected nor available: You cannot set a

pair configuration.

Number of secondary volumes Specify the total number of S-VOLs assigned to one P-VOL. This includes existing pairs.For SI, this item is blank.

Initial MU number The initial MU number.Limits: 0 to 63For SI and HTI, zero (0) is shown.



Available LDEVs table

Item Description

Use Primary Volumes of Snapshot Pairs Specifies whether the SS pair’s P-VOL is used or not.Values:• Yes: Only the existing pair’s P-VOLs are

shown in the Available LDEVs table.• No: Only the pair’s LDEV that have not yet

been created are shown in the Available LDEVs table.

For SI and ShadowImage for Mainframe, this item is blank.

Port ID Port name of the LDEV’s LUN path. For ShadowImage for Mainframe, this item is blank.

Host Group Name Host group name of the LDEV’s LUN path. Default: AnyFor ShadowImage for Mainframe, this item is blank.

Select Pool button Click to open the Select Pool window. Use this window to name and identify the pool.If you select Yes as the Use Primary Volumes of Snapshot Pairs, this button in unavailable.In SI or in ShadowImage for Mainframe, data is not shown.

Add Adds the selected LDEVs from the Available LDEVs table to the Selected LDEVs table.

Remove Returns the selected LDEVs from the Selected LDEVs table back to the Available LDEVs table.

Item Description

LDEV ID The identifier of the LDEV. You can specify the LDEV identifier as the P-VOL.

LDEV Name The name of the LDEV.

Port ID The port name of the LDEV’s LUN path.For ShadowImage for Mainframe, this item is blank.

LUN ID LUN ID of the LDEV's LUN path.For ShadowImage for Mainframe, this item is blank.

Host Group Name Host group name of the LDEV’s LUN path.For ShadowImage for Mainframe, this item is blank.


Selected LDEVs table

Provisioning type Provisioning type of the LDEV.Values:• Basic: Internal volume• HDP: DP-VOL• External: External volume

Emulation type The emulation type of the LDEV.

Capacity The capacity of the LDEV.

CLPR The CLPR number of the LDEV.

Number of Secondary Volumes Shows the number of S-VOLs.

Primary Volumes If you use the LDEV as an S-VOL for an existing pair, shows information about the P-VOL.Values:• LDEV ID: LDEV identifier • LDEV Name: LDEV name• Port ID: Port name of the LDEV’s LUN path• Host Group Name: Host group name of the LDEV’s

LUN path• LUN ID: LUN ID of the LDEV's LUN path• Emulation type: The volume’s emulation type• Capacity: The volume’s capacity• CLPR: The volume’s CLPR numberFor SI or SIz, this item is blank.

Mirror unit The mirror unit number. If you are not using the LDEV as a S-VOL for an existing pair, a hyphen (-) is shown.For SI or SIz, this item is blank.

Pool Name (ID) The pool’s name and identifier.For SI or SIz, this item is blank.

Item Description

Item Description

LDEV ID Selected P-VOL’s LDEV identifier

LDEV Name Selected P-VOL’s LDEV name

Port ID Port name of the LDEV’s LUN path. For SIz, this item is blank.

Host Group Name Host group name of the LDEV’s LUN path.For SIz, this item is blank.

LUN ID LUN ID of the LDEV's LUN path.For SIz, this item is blank.



Provisioning type Type of LDEVValues:• Basic: Internal volume• HDP: DP-VOL• External: External volume

Emulation type Emulation type of LDEV

Capacity Capacity of LDEV

CLPR CLPR number

Number of Secondary Volumes

Shows the number of S-VOLs.

Primary volume The information about the P-VOL is shown if the LDEV is the S-VOL of the existing pair.Values:• LDEV ID: P-VOL’s LDEV identifier: • LDEV Name: P-VOL’s LDEV name• Port ID: Port name of the P-VOL LDEV’s LUN path• Host Group Name: Host group name of the P-VOL

LDEV’s LUN path• LUN ID: LUN ID of the P-VOL LDEV's LUN path• Emulation Type: P-VOL’s emulation type• Capacity: P-VOL’s capacity• CLPR: P-VOL’s CLPR number.For SI or SIz, this item is blank.

Mirror unit Mirror unit number.If you are not using the LDEV as a S-VOL for an existing pair, a hyphen (-) is shown.For SI or SIz, this item is blank.

Pool Name (ID) The pool’s name and identifier.For SI or SIz, this item is blank.

Item Description


Select Pool window

Available Pools table

Item Description



Capacity Values:• Total: The total pool capacity.• Used: The amount of pool capacity that is used.• Used (%): The percentage of pool capacity that is

used. *For Used (%), the number truncated to an integer is shown.

Drive Type/RPM The hard disk drive type and RPM.


Information about the pool threshold.

CLPR The ID and name of the CLPR (ID:CLPR).

Detail Click to open the Pool Properties window.



Select Secondary Volumes window

Available LDEVs table

Item Description

Capacity Allows you to filter the available LDEVs according to the capacity you select.

The remaining number you have to select

Refers to the selected P-VOLs in the Selected Pairs table with no assigned S-VOL.

Exclude Paired Volumes When checked, volumes already in a pair are not shown. This item is shown only when SI is specified.

Port ID Filters LDEVs in the Available LDEVs table by the Port ID.For SIz, this item is blank.

Host Group Name Filters LDEVs in the Available LDEVs table by the Host Group Name.Default: AnyFor SIz, this item is blank.

Set button Click to move the selected LDEV to the Selected Pairs table.

Clear button Click to return the selected S-VOL from the Selected Pairs table back to the Available LDEVs table.

Item Description

LDEV ID The identifier of LDEV, which you can specify as the S-VOL.

LDEV Name LDEV’s name


Selected Pairs table

Port ID Port name of the LDEV’s LUN path. For SIz, this item is blank.

Host Group Name Host group name of the LDEV’s LUN path.For SIz, this item is blank.

LUN ID LUN ID of the LDEV's LUN path.For SIz, this item is blank.

Emulation type LDEV’s emulation type

Capacity LDEV’s capacity

Provisioning type Provisioning type of the LDEV.Values:• Basic: Internal volume• DP: DP-VOL• External: External volume• Snapshot: HTI or SS volume

CLPR LDEV’s CLPR number

Detail Click to open the LDEV Properties dialog box, which contains additional information for the selected LDEV.

Item Description

Item Description

Primary Volume Defines the P-VOL information.Values:• LDEV ID: P-VOL’s LDEV identifier• LDEV Name: P-VOL’s LDEV name.

For unallocated LDEVs, a hyphen (-) is shown.• Port ID: Port name of the P-VOL LDEV’s LUN path

For SIz, this item is blank.• Host Group Name: Host group name of the P-VOL

LDEV’s LUN pathFor SIz, this item is blank.

• LUN ID: LUN ID of the P-VOL LDEV's LUN pathFor SIz, this item is blank.

• Emulation type: P-VOL’s emulation type• Capacity: P-VOL’s volume capacity



Edit Mirror Units window

Secondary Volume Defines the S-VOL information.Values:• LDEV ID: S-VOL’s LDEV identifier. If an LDEV is not

allocated, this item is blank.• LDEV Name: S-VOL’s LDEV name. If an LDEV is not

allocated, a hyphen (-) is shown.• Port ID: Port name of the S-VOL LDEV’s LUN path.

For SIz, this item is blank.• Host Group Name: Host group name of the S-VOL

LDEV’s LUN path.For SIz, this item is blank.

• LUN ID: LUN ID of the S-VOL LDEV's LUN path.For SIz, this item is blank.

• Emulation type: S-VOL’s emulation type.• Capacity: S-VOL’s volume capacity.

Copy type Shows the copy type.Values:• SI-L1: SI L1 pair• SI-L2: SI L2 pair• TI: HTI pair• SS: SS pair• SIMF: SIz pair

Mirror unit The pool’s mirror unit number.In HTI, this item is blank.

Pool name (ID) The pool’s name and identifier.In SI or SIz, this item is blank.

Edit Mirror Units button Click to open the Edit Mirror Units window where you change mirror unit numbers.In HTI, this item is blank.

Remove button Click to remove the pair from the table.

Item Description


Edit Mirror Units table

Confirm window

Selected Pairs table

Item Description

Mirror Unit Specifies the mirror unit number.

Item Description

Primary volume Defines the P-VOL information.Values:• LDEV ID: P-VOL’s LDEV identifier• LDEV Name: P-VOL’s LDEV name• Port ID: Port name of the P-VOL LDEV’s LUN path

For SIz, this item is blank.• Host Group Name: Host group name of the P-VOL


• LUN ID: LUN ID of the P-VOL LDEV's LUN pathFor SIz, this item is blank.

• Emulation type: P-VOL’s emulation type• Capacity: P-VOL’s volume capacity• CLPR: P-VOL’s CLPR number



Copy type The copy type.Values:• SI-L1: SI L1 pair• SI-L2: SI L2 pair• TI: HTI pair• SS: SS pair• SIMF: SIz pair

Secondary volume Defines the S-VOL information.Values:• LDEV ID: S-VOL’s LDEV identifier• LDEV Name: S-VOL’s LDEV name• Port ID: Port name of the S-VOL LDEV’s LUN path

For SIz, this item is blank.• Host Group Name: Host group name of the S-VOL


• LUN ID: LUN ID of the S-VOL LDEV's LUN pathFor SIz, this item is blank.

• Emulation type: S-VOL’s emulation type• Capacity: S-VOL’s volume capacity• CLPR: S-VOL’s CLPR number

Pool Name (ID) The pool’s name and identifier.In SI or SIz, this item is blank.

Mirror Unit The pool’s mirror unit number.In HTI, this item is blank.

Item Description

C

Pair operations (secondary window) C–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Pair operations (secondary window)

This appendix provides instructions on using the previous version of the SN GUI, which opens in a secondary window, and CCI.

You can do all pair operations in the new SN GUI. For more information about the pair operations, see Pair operations on page 5-1.

□ Pair operations workflow

□ Checking pair status

□ Creating a pair

□ Splitting pairs

□ Resynchronizing pairs

□ Restoring pairs

□ Deleting pairs


C–2 Pair operations (secondary window)

Pair operations workflowUse the following workflow to perform pair operations:• Check the pair status. The pairs must have a specific status before you

can do a pair operation. Check the pair status to confirm an operation completed successfully.

• Create the pair.The V-VOL is transformed as a virtual copy of the P-VOL.

• Split the pair.A point-in-time snapshot of the P-VOL in the V-VOL is created. This allows another software application to use the V-VOL.

• Resume the pair.The SS data is discarded. The V-VOL is returned to a virtual copy of the P-VOL.

• Delete the pair.The pair relationship between the pair volumes ends.

• Restore the pair.The pair is restored to the point-in-time data of the last snapshot.

Checking pair statusPair operations require a specific status. Check the pair status before performing an operation.• For more information about checking pair status, see Monitoring the

system in the secondary window on page D-2.• For the operations allowed for specific statuses, see Pair status

definitions on page D-3.

Creating a pairCreating a pair changes the V-VOL to a virtual copy of the P-VOL. Updates to the P-VOL are reflected in the V-VOL until you split the pair.

Prerequisite Information• The data pool and V-VOL for the new pair must exist. For more

information about installing and configuring data pools and V-VOLs, see Copy-on-Write Snapshot installation and configuration on page 3-1.

• Review the pair volume requirements. For more information, see Copy-on-Write Snapshot planning and design on page 2-1.

• The pair volumes must be in “SMPL” status.• Use the same data pool for all pairs sharing a single P-VOL.

For example: Three pairs with the same P-VOL must use the same data pool.

• Run the paircreate command when the data pool capacity is within the threshold.


• Running the paircreate command immediately after deleting previous SS data takes a longer time to complete.

• The CCI hide mode (-m noread) is not supported for S-VOLs (V-VOLs). If you specify it, the paircreate completes normally, but the hide mode is ignored.

• When using an HP-UX host server, you must create the SS pair before you run the command for recognizing the device or V-VOL on the host server.

From a command prompt, run the CCI paircreate command. The pair status changes to “PAIR”.

For more information, see the Hitachi Command Control Interface Installation and Configuration Guide.

Creating pairs in a consistency groupThis topic provides a summary of the steps needed to create pairs in a consistency group. For more information about creating pairs, see the Hitachi Command Control Interface Installation and Configuration Guide.

Prerequisite information• Use different consistency groups for each pair sharing a P-VOL.• Review the system requirements for consistency groups. For more

information, see Consistency group system requirements on page 2-2.• Review the consistency group information. For more information, see

the Hitachi Command Control Interface Installation and Configuration Guide.

• In the same CCI configuration file consistency group, do not mix pairs that you have created using the At-Time Split operation with other pairs. If you mix these pairs, the pairsplit command terminates abnormally and the integrity of stored SS data cannot be ensured.

1. From a command prompt, run the paircreate command.Include the option for specifying the consistency group number.

2. Add more pairs to the same consistency group by running the paircreate command and specifying the same consistency group number defined in Step 1.

Caution: If a volume is recognized by the HP-UX host server, do not use the volume as a V-VOL. Otherwise an error occurs and the host server can terminate.

For more information about recovering a terminated HP-UX host server, see Recovering a terminated HP-UX host server on page 7-6.

Note: Specifying a consistency group number automatically enables the At-Time Split operation.



Splitting pairsSplitting a pair creates a virtual point-in-time copy of the P-VOL. The following occurs when you split a pair:• The P-VOL continues receiving updates from the host, but updates are

not reflected in the V-VOL.• The current P-VOL data blocks are copied to the data pool. Pointers in

the V-VOL follow this original data to the data pool, maintaining the point-in-time copy.

You can split one pair or multiple pairs belonging to a consistency group.

Prerequisite information• The pair must be in “PAIR” status.• If you the P-VOL is paired with two or more V-VOLs, the pairs cannot be

in “COPY(RS-R)/RCPY” status. Running the pairsplit operation while the pair is in this status can abnormally end the operation.

• Do not run the pairresync -restore command on a pair while a pairsplit operation is being performed on a related pair (a pair that shares the same P-VOL). Running this command can abnormally end the pairsplit operation.

• SS does not support Quick Split mode.

For more information about the requirements for consistency group operations, see Consistency group system requirements on page 2-2.

To split a pair, from a command prompt, run the CCI pairsplit command. For more information about this command, see the Hitachi Command Control Interface Installation and Configuration Guide.

To split pairs in a consistency group, from a command prompt, run the CCI pairsplit command on the consistency group that is a target of the At-Time Split operation.

When the pairsplit completes, the pair status changes to “PSUS”.

Resynchronizing pairsResynchronizing pairs deletes the SS data in the data pool and transforms the V-VOL as a mirror of the current data in the P-VOL. Resynchronizing a pair increases the capacity in the data pool.

Prerequisite information• The pair status must be “PSUS”.• If a related pair is using the SS data in the data pool, then only the SS

ID is deleted for the resynchronized pair; the data is not deleted from the pool.

To resynchronize a pair, use the CCI pairresync command. The pair status changes to “PAIR”.

For more information about this command, see the Hitachi Command Control Interface Installation and Configuration Guide.


Restoring pairsWhen you restore a pair, the SS data in the data pool is copied back to the P-VOL. This restores P-VOL data to the point when the pair was split.

Prerequisite information• The pair must be in “PSUS” status.• SS does not support the Quick Restore operation.

To restore a pair, from a command prompt, run the CCI pairresync -restore command. The pair status changes to “PAIR”.

Deleting pairsDeleting pairs ends the relationship between the P-VOL and V-VOL. SS data for the pair is deleted from the pool.

Prerequisite information• The pair must be in “PAIR”, “PSUS”, or “PSUE” status.• It can take several seconds to ten minutes for the pair to delete. If you

are using a large area of the pool for SS data or if you are deleting more than one pair, it can take ten minutes for the pair to delete.

Deleting a single pairTo delete a single pair, use the CCI pairsplit -S command.

Deleting multiple pairs related to a port or host groupUse the SN to delete multiple pairs from a port or host group.1. In the SN, click Actions > Local Replications > SI/SS > Pair

Operation.

2. Change to Modify mode by clicking the icon.3. In the Pair Operations window tree, select the port or host group that

contains the pairs you want to delete.4. In the Volume list, select the SS pairs you want to delete, right-click,

and select Pairsplit-S from the menu.



5. In the Pairsplit-S dialog box, confirm that the pairs you want to delete are shown and selected, then click OK. The selected pairs are shown in the Preview list.

6. In the Pair Operations window, click Apply.7. Click OK on the confirmation message.

The pairs are deleted.

Deleting multiple pairs related to a poolUse the SN to delete multiple pairs from a pool.1. In the SN, click Actions > Local Replications > SI/SS > COW

Snapshot.

2. Change to Modify mode by clicking the icon.3. In the C.O.W. Snapshot window tree, complete the following:

a. Select the pool containing the pairs you want to delete.b. From the list of pairs or volumes that are shown in the volume list,

select all the pairs you want to delete, right-click and select the Pairsplit-S command.

4. In the Pairsplit-S dialog box, review the pairs you have selected and click OK. The dialog box closes. The list of pairs you want to delete are shown in the Preview list.

5. Click Apply, then click OK on the confirmation message.The pairs are deleted.

Figure C-1 Pairsplit-S Dialog box

D

Copy-on-Write Snapshot monitoring and maintenance (secondary window) D–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Copy-on-Write Snapshot monitoringand maintenance (secondary window)

This appendix provides instructions for monitoring SS using the previous version of the SN GUI, which opens in a secondary window.

You can do maintenance and similar monitoring operations in the new SN GUI. For more information about maintenance on the new SN GUI, see Copy-on-Write Snapshot monitoring and maintenance on page 6-1.

□ Monitoring the system in the secondary window

□ Maintaining the system


D–2 Copy-on-Write Snapshot monitoring and maintenance (secondary window)

Monitoring the system in the secondary windowMonitoring helps you to keep track of your pairs and volumes in their current and past conditions. Monitoring is an ongoing activity.

You can monitor the following SS elements:• Monitoring pair information, license capacity, status on page 6-2 (status

definitions included) • Monitoring pair volume details on page D-3 • Monitoring S-VOL path information on page D-5• Monitoring number of pairs and license information on page D-6• Monitoring pair operation history on page D-8

Monitoring pair statusMonitor pair status before and after performing pair operations.• Each operation requires a specific status or statuses. To do a pair

command, first check the pair’s status.• Pair status changes when you do an operation. Check the status to

ensure that the pairs are operating correctly and that the status is changing to the appropriate state during and after the operation.

You can monitor the pair status manually using the SN. Repeat the monitoring process frequently. You can use the SN to set up email notifications when you experience problems during a pair operation.

To monitor pair status1. In the SN, click Actions > Local Replications > SI/SS > Pair

Operation.

2. In the Pair Operation window, locate the pair whose status you want to review. Review pair status in the Status column.

You can view more details by right-clicking a pair and selecting Detail. For more information about monitoring pair volume, see Monitoring pair volume details on page D-3.

Note: Both SS and SI pairs are shown in the Pair list. SS V-VOLs are shown in the S-VOL column.

Caution: (Using monitoring software applications on a host server) If you have installed and are running a software application on a host server to monitor the volumes of SS pairs, the following problems can occur:• An S-VOL whose status is not “PSUS” (or “PFUS”) rejects access from

the host, possibly causing problems for the monitoring software application whose access is rejected.

• If the host computer connects to more than one port, other ports may also go offline when the S-VOL rejects host access.

To solve these problems, stop the monitoring software application.


Pair status definitions

For more information about pair status descriptions, see Pair status definitions on page 6-2. Click File/Refresh to ensure the pair status data is current.

The status names are slightly different in the new SN GUI than in the previous GUI version showing in the secondary window. The following table shows the new and previous status names.

Statuses required for pair operations

To perform a pair operation, the pair must have a specific status. The following table shows the CCI pair operations and the required statuses to complete the pair operation.

Monitoring pair volume detailsYou can review more details for a pair and pair-volumes than are available on the Pair Operation window. This includes volume capacity, related pool ID, pool usage, and so on.1. In the SN, click Actions > Local Replications > SI/SS > Pair

Operation.2. In the Pair Operation window, select the desired SS pair on the

Volume list, right-click and select Detail.

Current SN pair status names Previous SN pair status names

SMPL (is not shown) SMPL

COPY COPY, COPY(RS)/COPY

PAIR PAIR

PSUS PSUS

PFUS PSUS

PFUL PAIR

RCPY COPY(RS-R)/RCPY

PSUE PSUE


paircreate SMPL

paircreate –split PAIR/PFUL

pairsplit PAIR/PFUL

pairresync PSUS/PFUS, PSUE

pairresync -restore PSUS/PFUS

pairsplit -S PAIR/PFUL, PSUS/PFUS, PSUE



3. In the Detail dialog box, check pair and volume details.The following table shows descriptions of the items in the Detail dialog box.

Items Descriptions

P-VOL P-VOL LDKC number, control unit (CU) number, and LDEV number.

Emulation P-VOL emulation type.

Capacity (MB) P-VOL capacity in megabytes.

Capacity (blocks) P-VOL capacity in blocks.

CLPR (P) P-VOL cache logical partition.

Pool ID The pool’s pool ID in which the P-VOL is registered.

Amount of pool used by P-VOL (GB)

The amount of pool capacity the P-VOL is using.

Pool usage rate by P-VOL

Pool usage rate of the P-VOL.


Monitoring S-VOL path informationYou can view path information for the S-VOL. 1. In the SN, click Actions > Local Replications > SI/SS > Pair

Operation.2. In the Pair Operation window, select a pair in the Volume list, right-

click and select S-VOL Path.

Snapshot Pair Detail list

Shows the SS pair details.Values:• MU: SS ID.• S-VOL: LDKC number, CU number, and LDEV number.• Status: The pair’s status.• Date: Time when the SS data was stored in the pool.• Pool used(GB): The amount of the pool’s capacity the S-VOL is using.• Sync.: Consistency rate of data of the P-VOL and the S-VOL.• CLPR (S): S-VOL’s cache logical partition (CLPR).• CTG: The pair’s consistency group number.

Note: When the consistency group is not specified, dotted lines (---) are shown.

• SvolMode: Shows the status of the S-VOL.For more information about SvolMode, see the SvolMode item in Volume list on page E-3.

Refresh the window after this dialog box is closed. check box

If you select the check box, the information shown in the SI Pair Operation window is updated after the Detail dialog box closes. If you do not select the check box, the information stays the same when you close the dialog box.

Refresh Updates the information in the Detail dialog box.

Close Closes the Detail dialog box.

Items Descriptions



3. In the S-VOL Path dialog box, check S-VOL information as desired. The following table shows descriptions of the items in the S-VOL Path dialog box.

Monitoring number of pairs and license informationYou can review information related to pairs and license capacity using the Information dialog box.

Figure D-1 S-VOL Path dialog box

Items Descriptions

Pair Information box

Path information for the selected pairs. P-VOL and S-VOL volumes are shown in the AAA-BB-CCC(XX:YY:ZZ) format.• AAA: Port ID (cluster name and channel number)• BB: Group number (GID) of host group• CCC: LU number• XX:YY:ZZ: LDKC number:CU number: LDEV number

S-VOL Path Information box

Path information for the S-VOLs selected in the Pair Information box.• Port: The port ID• GID: The group number of host group• LUN: LU number

Close Closes the S-VOL Path dialog box.


1. In the SN, click Actions > Local Replications > SI/SS > Pair Operation.

2. In the Pair Operation window, right-click and select Information.

3. In the Information dialog box, review pair and license information as desired. The following table shows descriptions of the items in the Information dialog box.

Figure D-2 Information dialog box

Items Descriptions

ShadowImage pair(s)

Number of SI pairs in the XXXX / YYYY format, where XXXX is SI pairs and YYYY is the number of SI and SIz pairs.

C.O.W. Snapshot pair(s)

Number of SS pairs.Maximum number of pairs: 16,384If you create SI, Volume Migration, and Compatible FlashCopy® V2 pairs in the same storage system, the maximum number of pairs that you can create may be less than 16,384 minus YYYY. YYYY is the number of SI and SIz pairs.

Reserved volume(s)

The number of reserved volumes of SI is shown in the format of XXXX / YYYY. XXXX is the number of reserved SI volumes. YYYY is the total number of reserved SI and SIz volumes.Reserved volumes include S-VOLs of SI and SIz.

Remaining pair table(s)

Number of usable pair tables in the storage system shown in XXXXX / YYYYY format. XXXXX is the number of usable pair tables. YYYYY is the maximum number of pair tables.

Remaining differential table(s)

Number of usable differential tables in the storage system in the XXXXXX / YYYYYY format. XXXXXX is the number of usable differential tables. YYYYYY is the maximum number of differential tables.For more information about calculating maximum number of pairs based on differential tables, see Calculating maximum SS pairs based on differential tables workflow on page 2-7.



Monitoring pair operation historyYou can review the operations that have been performed on a pair using the History window. The History window shows information about copying pairs. The storage system saves up to 512,000 records of the latest operations. If there are more than 16,384 records of pair operations, the list in the History window is divided into multiple pages and only the list that is currently shown is sorted.1. In the SN, click Actions > Local Replications > SI/SS > History.

SS and HTI pair information is shown in the bottom part of the History window. The list sorts based on the column heading you click.

2. In the History window, click the C.O.W. Snapshot tab.3. In the History window, in the C.O.W. Snapshot tab, perform the

following in the COW Snapshot History list. To change the displaying order, click a column in the list. The list is

sorted based on the items in the clicked column. If multiple pages of pair operations exist, click Next to move to the

next page. To move to the previous page, click Previous.

Click the same column again to switch the sorting order (Ascending or Descending).

To update the window with the latest information, click File > Refresh.

If there are many records of tasks, use the scroll icons. The list scrolls and the operation history that has not been shown is shown.

Used volume (TB) SI license information in the X(Y) format, where X is license capacity SI is using and Y is total license capacity reserved for SI. If there is no limit on license capacity, Unlimited is shown.

C.O.W. Snapshot Used volume (TB)

SS license information in the X(Y) format, where X is license capacity SS is using and Y is total license capacity reserved for SS. If there is no limit on license capacity, Unlimited is shown.

Close Closes the Information dialog box.

Items Descriptions

Note: If some of the pairs include LUSE volumes or if the subsystem includes 500 or more of the following pairs and migration plans, you may need to wait until the History window shows the operation history:• SI pairs• SS pairs• SIz pairs• Compatible FlashCopy® V2• Volume Migration• HTI pair

Note: If only one page of pair operations exists, the Previous and Next buttons are unavailable.


To expand the display area of the list in the History window, click and drag down the frame border that divides the History window into upper and lower panes.

Maintaining the systemYou can make changes to the storage system, data pools, and V-VOLs to fit your requirements.

For more information about maintaining the SN, see Maintaining the storage system on page 6-6.

E

Copy-on-Write Snapshot GUI reference (secondary window) E–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Copy-on-Write Snapshot GUIreference (secondary window)

This appendix describes SS windows and dialog boxes in the previous version of the SN GUI, which opens in a secondary window.

Note: The P-VOL and S-VOLs listed in the SN may end in special symbols. An LDEV number that ends with a pound or gate symbol (#) indicates an external volume (for example, 00:00:01#). An LDEV number that ends with the letter “X” indicates that HDP is using a V-VOL. For example, 00:00:01X.

□ Pair Operation window

□ History window

□ C.O.W. Snapshot window


E–2 Copy-on-Write Snapshot GUI reference (secondary window)

Pair Operation windowUse the Pair Operation window to view SS and SI pair and volume information for the selected port or host group.

You can do the following from the Pair Operation window:• Monitoring pair information, license capacity, status on page 6-2• Monitoring pair volume details on page D-3• Monitoring S-VOL path information on page D-5• Monitoring number of pairs and license information on page D-6

Note: This section references only the items related to SS pairs. For more information about SI, see the Hitachi ShadowImage® User Guide.

Item Description

Display Filter button

Click to open the Display Filter dialog box. Use this dialog box to filter to display specific volumes in the Pair list.

Tree Shows port and host group. When you click one of these, associated pairs show in the pair/volume list. If you select Storage System, pair or volumes are not listed.

Pair/volume list

Shows volume and pair information. You can sort this list by column in ascending or descending order. For more information, see Volume list on page E-3.


Volume listThe main list in the Pair Operation window is the Volume list. This list shows SS and SI volume and pair information.

You can filter the list to show only SS volumes. To do this, click Display Filter.

Icons The following are the SS icons and their meanings:

: Storage system

: Port

: Host group

: LUN or SMPL volume

: SS pairFor more information about the SI icons, see the Hitachi ShadowImage® User Guide.

Preview Shows the operations you have specified but have not yet applied to the storage system. You can change or delete the operations by right-clicking the item in the Preview list.

Apply Applies the operations shown in the Preview list to the storage system. If the specified operations are applied successfully, the Preview list will be cleared.If an error occurs during an operation, the failed operation will remain

in the Preview list with an error icon ( ) shown in front. The error dialog box shows the details of the error (error code and message).For more information about the SS error code list, see the Hitachi Storage Navigator Messages.

Cancel Cancels all the operations set in the Preview list.

Item Description

Item Description

P-VOL P-VOL information in AAA-BB-CCC(XX:YY:ZZ) format.Values:• AAA: Port ID (cluster and channel number)• BB: Group number of host group• CCC: LU number• XX:YY:ZZ: LDKC number:CU number:LDEV numberA device ID ending in # (e.g., 00:00:3C #), indicates the LDEV is an external volume. For more information about external volume, see the Hitachi Universal Volume Manager User Guide.A device ID ending in X (e.g., 00:00:3C X) indicates the LDEV is an HDP V-VOL. For more information about V-VOL, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.



MU Mirror unit (MU) number of the SS pair, formed with the P-VOL. The storage system assumes the same numbers of P-VOLs as S-VOLs. For example, when a P-VOL is paired with three S-VOLs, though just one P-VOL exists, the system assumes that there are three P-VOLs. These virtual P-VOLs are mirror units, MUs. The MU numbers identify the virtual P-VOLs seen only by the system.Note: If the pair is in “SMPL” status, three hyphens (---) are shown.

Status Pair status.

S-VOL S-VOL information in AAA-BB-CCC(XX:YY:ZZ) format.Values:• AAA: Port ID (cluster and channel number)• BB: Group number of host group• CCC: LU number• XX:YY:ZZ: LDKC number:CU number: LDEV numberOnly one path is listed, which is the path connected to the first port in the tree view.A device ID ending in # (e.g., 00:00:3C #), indicates that the LDEV is an external volume. For more information about external volume, see the Hitachi Universal Volume Manager User Guide.A device ID ending in X (e.g., 00:00:3C X) indicates that the LDEV is an HDP V-VOL. For more information about V-VOL, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

CTG The pair’s consistency group number. When the consistency group is not specified, three hyphens (---) are shown.

SvolMode Shows the status of the S-VOL. When data is not written in the S-VOL, three hyphens (---) are shown. When the data is written in the S-VOL, W is shown.

Copy Pace Not for SS, three hyphens (---) are shown.

Sync. Indicates the percentage of pair synchronization, and changes based on the pair status.Values:• For volumes or pairs in “SMPL” or “SMPL (PD)” status, dashes (---

) are shown.• The percentage (%) of data in the S-VOL and P-VOL for volumes

in “COPY”, “PAIR”, “COPY(RS)/COPY”, “COPY(RS-R)/RCPY”, “PSUS”, or “PSUE” status.

Emulation Emulation type of the volume.

Capacity (MB) Volume storage capacity in megabytes.

CLPR (P) P-VOL cache logical partition.

CLPR (S) S-VOL cache logical partition.

Right-click command menu

Commands you can perform. If you select and right click the SS pair volumes in the volume list, the menus in the following table are shown. For more information about the command descriptions, see the following table.

Item Description


Preview listThe Preview list shows the operations and changes you have made from the Pair Operation window.

You can review your changes, modify the operation or your changes, and apply them to the storage system: • To modify an operation, right-click the row and select Delete or Modify.• To display error messages, click Error.

The Preview list opens below the Volume list. The following table shows descriptions of the items in the Preview list.

Previous If the total number of the volumes in the storage system has exceeded the maximum number of volumes, multiple pages exist. Click to open the previous page in the list.Note: If only one page exists, this button is unavailable.For more information about the maximum number of pool-VOLs allowed in a data pool, see Consistency group system requirements on page 2-2.

Next If the total number of the volumes in the storage system has exceeded the maximum number of volumes, multiple pages exist. Click to open the next page of the volume list.Note: If only one page exists, this button is unavailable.For more information about the maximum number of pool-VOLs allowed in a data pool, see Consistency group system requirements on page 2-2.

Message If a volume or pair does not exist, Message is shown. If Message is shown in the Volume list, click a different icon in the tree in the left area of the Pair Operation window.

Item Description

Item Description

P-VOL P-VOL information in AAA-BB-CCC(XX:YY:ZZ) format.Values:• AAA: Port ID (cluster and channel number)• BB: Group number of host group• CCC: LU number• XX:YY:ZZ: LDKC number:CU number:LDEV number

MU The MU number of the SI pair formed with the P-VOL.

S-VOL S-VOL information in AAA-BB-CCC(XX:YY:ZZ) format.Values:• AAA: Port ID (cluster and channel number)• BB: Group number of host group• CCC: LU number• XX:YY:ZZ: LDKC number:CU number:LDEV number

Copy Pace Indicates the speed that data is copied according to the pair status.

CLPR (P) P-VOL cache logical partition is shown.



Data in the status bar below the Preview list indicate the number of changes, the type of change (the operation), and any command options.

Command menuWhen you right-click a row or other item, a menu opens and shows commands. The following table lists the commands.

History window You can view your operation history and its associated data in the History window. The upper pane shows SI history. To show the SS or HTI history in the lower pane, click the C.O.W. Snapshot or Thin Image tab.

For more information about SI history, see the Hitachi ShadowImage® User Guide.

CLPR (S) S-VOL cache logical partition is shown.

Error Code If you click Apply and then the operations in the Preview list fail, an error code indicates the cause of the error.

Menu Select and right-click items in the Preview list to show the menu.Options:• Detail: Opens the error message dialog box, which shows the

error code and message.For SS error codes, see Hitachi Storage Navigator Messages.

• Delete: Cancels the selected task and removes the task from the Preview list on the Pair Operation window.

The unavailable commands are for SI pairs.For more information about the SI commands, see the Hitachi ShadowImage® User Guide.

Preview X(Y) X denotes the total number of operations that are shown in the Preview list.Y denotes the type of operation.

Item Description

Command Function

Detail Opens the Detail dialog box, which shows detailed information for the selected volume or pair.

Pairsplit-S Opens the Pairsplit-S dialog box, in which you delete SS pairs.

S-VOL Path Opens the S-VOL Path dialog box, in which you view information about the S-VOL path.

Information Opens the Information dialog box, which shows the number of pairs or reserved volumes.

Grayed-out commands

Reserved for SI.

Paircreate, Pairsplit

Opens the Paircreate and Pairsplit dialog boxes. These dialog boxes are reserved for SI. You cannot create or split SS pairs from these dialog boxes. Use CCI to create or split SS pairs.


Item Description

Previous If the total number exceeds 16,384 of operations, multiple pages exist. Click to open the previous page of the operation history list.Note: If only one page exists, this button is unavailable.

Next If the total number exceeds 16,384 of operations, then multiple pages exist. Click to open the next page of the operation history list.Note: If only one page exists, this button is unavailable.

Date Shows date and time of the operation in the YYYY / MM / DD hh:mm:ss format.• YYYY: year• MM: month• DD: day• hh: hour• mm: minute• ss: second



Reference codesReference code and message information about SS and HTI operations is shown in the Code and Message columns in the History window.

The following table lists descriptions for the columns.

C.O.W. Snapshot windowThe C.O.W. Snapshot window shows SS pool information.

P-VOL The operation’s P-VOL, identified by LDKC:CU:LDEV.A device identifier ending in the pound sign (#) (e.g., 00:00:3C #), indicates that the LDEV is an external volume.For more information about external volumes, see the Hitachi Universal Volume Manager User Guide.Note: A device identifier ending in ‘X’ (e.g., 00:00:3C X) indicates that the LDEV is an HDP V-VOL.For more information about V-VOL, see the Hitachi Virtual Storage Platform Provisioning Guide for Open Systems.

S-VOL The operation’s S-VOL (V-VOL), identified by LDKC:CU:LDEV.A device ID ending in V (e.g., 00:00:01 V) indicates that the LDEV is a V-VOL.

MU The SS ID.

Pool ID ID of the related data pool.

Code SS reference code, which indicates the kind of operation that was performed. For more information, see Reference codes on page E-8.

Message Describes the operation. Related to the reference code.

Item Description

Code Message Description

2001 PAIR The pair was created.

2011 PSUS The pair was split.

2021 SMPL The pair was deleted.

2030 COPY(RS-R) START Pair restoration started.

2031 COPY(RS-R) END Pair restoration ended normally.

2032 COPY(RS-R) ENDED ABNORMAL

Pair restoration ended abnormally.

2051 COPY(RS) The SS data was deleted.

2070 PSUE(ABNORMAL END) A failure occurred and the status of the pair changed to PSUE.

2040 INITIALIZE START Initialization started.

2041 INITIALIZE END Initialization ended normally.

2042 INITIALIZE ENDED ABNORMAL

Initialization ended abnormally.


Item Description

Tree The pools in the storage system are shown with the following icons:

• : Storage system

• Pool:X: Pool in normal status (X indicates pool ID)

• Pool:X: Pool whose usage rate exceeds the threshold (X indicates pool ID)

• Pool:X: Blocked pool (X indicates pool ID)



Pool/volume list

The content of the main list is either data pools or pair volumes. This depends on whether you have selected Storage System or Pool from the tree.If Storage System is selected, all pools in the storage system are shown in this list.Values:• Pool ID: Pool ID.• Capacity (GB): The pool’s storage capacity.• Used Capacity (GB): The amount of the pool’s capacity that SS

pairs are using.• Usage rate: The pool’s usage rate.• Pool-VOL(s): Total number of pool-VOLs in the pool.If Pool is selected, the SS pairs that use the pool are shown in this list, with the following items:• P-VOL: Port ID, group number of the host group, and LUN (LDKC

number, CU number, and LDEV number of the volume) of the P-VOL.For P-VOL LUs with more than one path, only one path is listed. The path is connected to the first port within the ports configured to a path that are shown in the tree view of the Pair Operation window.

• MU: The SS ID.• Status: The status of the SS pair.• S-VOL: Port ID, group number of the host group, and LUN (LDKC

number, CU number, and LDEV number of the volume) of the S-VOL.For S-VOL LUs with more than one path, only one path is listed. The path is connected to the first port within the ports configured to a path that are shown in the tree view of the Pair Operation window. When the volume is unmounted, three hyphens (---) are shown.

• Pool used (GB): Capacity of the pool that is used by the S-VOL.• Sync.: Consistency rate of the data of the P-VOL and the S-VOL.• CTG: Consistency group number of the SS pair.

When the consistency group is not specified, three hyphens (---) are shown.

Pool Association Inf.: X GB / Y GB

X is the capacity in use of pool association information.Y is the maximum possible capacity of pool association information.The maximum possible capacity of pool association information is calculated, based on the assumption that the remaining space of the V-VOL management area is used as pool association information. If the remaining space of the V-VOL management area is used for pool management blocks, the maximum possible capacity of pool association information is decreased due to decrease in the remaining space of the V-VOL management area.

Item Description


Pool Mng. Block: X GB / Y GB

X indicates the capacity in use of the pool management blocks.Y indicates the maximum possible capacity of the pool management blocks.The maximum possible capacity of pool management blocks is calculated, based on the assumption that the remaining space of the V-VOL management area is used as pool management blocks. Using the remaining space of the V-VOL management area for pool association information decreases the maximum possible capacity of pool management blocks and decreases the remaining space of the V-VOL management area.Pool association information and a pool management block are the elements of V-VOL management area. To calculate the number of SS pairs you can create, know the capacity of the elements.Note: For Pool Information, the value shown for Total Capacity and the value shown for Pool Mng. Capacity : used are similar but may vary.Note: Adding and deleting pool-VOLs to and from the pool does not update this value, even when the Total Capacity for Pool Information is updated.

Command menu

When you right-click a pair in the pool/volume list, a menu with the Pairsplit-S command is shown. Click the command to open the Pairsplit-S dialog box.

Preview Shows the settings you have defined. They are not applied to the system until Apply is clicked. • P-VOL: Port ID, group number of the host group, and LUN of the

P-VOL.• MU: SS ID.• S-VOL: Port ID, group number of the host group, and LUN of the

S-VOL.• Error Code: Code for an error. If there is no error, three hyphens

(---) are shown.• Preview X(Y): Total number of operations shown in the Preview

list(X) and type of operation(Y).

Preview list command menu

Select and right-click a row in the Preview list to show the menu.Options:• Detail: Opens the error message dialog box, which shows the

error code and message.For more information about the SS error codes, see the Hitachi Storage Navigator Messages.

• Delete: Cancels the selected task and removes the task from the Preview list on the C.O.W. Snapshot window.

Apply Applies the operations shown in the Preview list to the storage system. The Preview list is cleared when the operations complete. If an error occurs, the failed operation remains in the Preview list. Details of the error (error code and message) are shown on the error dialog box.For more information about the SS error code list, see the Hitachi Storage Navigator Messages.

Cancel Cancels all operations in the Preview list.

Item Description

CA KD E F G H I J L M N O P Q R S T U V W X Y# B Z# A B C D E F G H I J L M N O P Q R S T U V W X

Glossary–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Glossary

This glossary defines the special terms used in this document. Click the letter links below to navigate.

#

3DCthree-data-center. Refers to the local, intermediate, and remote sites, or data centers, in which TrueCopy and Universal Replicator combine to form a remote replication configuration.

In a 3DC configuration, data is copied from a local site to an intermediate site and then to a remote site (3DC cascade configuration), or from a local site to two separate remote sites (3DC multi-target configuration).

A

alternate pathA secondary path (port, target ID, LUN) to a logical volume, in addition to the primary path, that is used as a backup in case the primary path fails.

arrayAnother name for a RAID storage system.

array groupSee RAID group.

at-time splitOperation that allows multiple pairsplit operations to be performed at a pre-determined time.



Glossary–2

audit logFiles that store a history of the operations performed from Storage Navigator and the service processor (SVP), commands that the storage system received from hosts, and data encryption operations.

B

base emulation typeEmulation type that is set when drives are installed. Determines the device emulation types that can be set in the RAID group.

BCbusiness continuity

BCMBusiness Continuity Manager

bladeA computer module, generally a single circuit board, used mostly in servers.

BLK, blkblock

bmpbitmap

C

C/TSee consistency time (C/T).

cacache

cache logical partition (CLPR)Consists of virtual cache memory that is set up to be allocated to different hosts in contention for cache memory.

capacityThe amount of data storage space available on a physical storage device, usually measured in bytes (MB, GB, TB, etc.).



cascade configurationIn a 3DC cascade configuration for remote replication, data is copied from a local site to an intermediate site and then to a remote site using TrueCopy and Universal Replicator. See also 3DC.

In a ShadowImage cascade configuration, two layers of secondary volumes can be defined for a single primary volume. Pairs created in the first and second layer are called cascaded pairs.

cascade functionA ShadowImage function for open systems that allows a primary volume (P-VOL) to have up to nine secondary volumes (S-VOLs) in a layered configuration. The first cascade layer (L1) is the original ShadowImage pair with one P-VOL and up to three S-VOLs. The second cascade layer (L2) contains ShadowImage pairs in which the L1 S-VOLs are functioning as the P-VOLs of layer-2 ShadowImage pairs that can have up to two S-VOLs for each P-VOL.

See also root volume, node volume, leaf volume, level-1 pair, and level-2 pair.

cascaded pairA ShadowImage pair in a cascade configuration. See cascade configuration.

shared volumeA volume that more than one replication function is using. For example, a volume that is the primary volume of a TrueCopy pair and the primary volume of a ShadowImage pair is a shared volume.

CCICommand Control Interface

CFLConfiguration File Loader. A Storage Navigator function for validating and running scripted spreadsheets.

CFWcache fast write

CGSee consistency group (CTG).

CTGSee consistency group (CTG).



Glossary–4

CHchannel

channel pathThe communication path between a channel and a control unit. A channel path consists of the physical channel path and the logical path.

CHAPchallenge handshake authentication protocol

CLcluster

CLIcommand line interface

CLPRcache logical partition

clusterMultiple-storage servers working together to respond to multiple read and write requests.

command deviceA dedicated logical volume used only by Command Control Interface and Business Continuity Manager to interface with the storage system. Can be shared by several hosts.

configuration definition fileDefines the configuration, parameters, and options of Command Control Interface operations. A text file that defines the connected hosts and the volumes and groups known to the Command Control Interface instance.

consistency group (CG, CTG)A group of pairs on which copy operations are performed simultaneously; the pairs’ status changes at the same time. See also extended consistency group (EXCTG).

consistency time (C/T)Shows a time stamp to indicate how close the target volume is to the source volume. C/T also shows the time stamp of a journal and extended consistency group.



controllerThe component in a storage system that manages all storage functions. It is analogous to a computer and contains a processors, I/O devices, RAM, power supplies, cooling fans, and other sub-components as needed to support the operation of the storage system.

copy-on-writePoint-in-time snapshot copy of any data volume within a storage system. Snapshots only store changed data blocks, therefore the amount of storage capacity required for each copy is substantially smaller than the source volume.

copy pairA pair of volumes in which one volume contains original data and the other volume contains the copy of the original. Copy operations can be synchronous or asynchronous, and the volumes of the copy pair can be located in the same storage system (local copy) or in different storage systems (remote copy).

A copy pair can also be called a volume pair, or just pair.

COWcopy-on-write

COW SnapshotHitachi Copy-on-Write Snapshot

CTGSee consistency group (CTG).

CTLcontroller

CUcontrol unit

currency of dataThe synchronization of the volumes in a copy pair. When the data on the secondary volume (S-VOL) is identical to the data on the primary volume (P-VOL), the data on the S-VOL is current. When the data on the S-VOL is not identical to the data on the P-VOL, the data on the S-VOL is not current.

CYL, cylcylinder



Glossary–6

cylinder bitmapIndicates the differential data (updated by write I/Os) in a volume of a split or suspended copy pair. The primary and secondary volumes each have their own cylinder bitmap. When the pair is resynchronized, the cylinder bitmaps are merged, and the differential data is copied to the secondary volume.

D

DASDdirect-access storage device

data consistencyWhen the data on the secondary volume is identical to the data on the primary volume.

data pathThe physical paths primary storage systems are using to communicate with secondary storage systems in a remote replication environment.

data poolOne or more logical volumes designated to temporarily store original data. When a snapshot is taken of a primary volume, the data pool is used if a data block in the primary volume is to be updated. The original snapshot of the volume is maintained by storing the to-be-changed data blocks in the data pool.

DBdatabase

DBMSdatabase management system

delta resyncA disaster recovery solution in which TrueCopy and Universal Replicator systems are configured to provide a quick recovery using only differential data stored at an intermediate site.

deviceA physical or logical unit with a specific function.

device emulationIndicates the type of logical volume. Mainframe device emulation types provide logical volumes of fixed size, called logical volume images (LVIs), which contain EBCDIC data in CKD format. Typical mainframe



device emulation types include 3390-9 and 3390-M. Open-systems device emulation types provide logical volumes of variable size, called logical units (LUs), that contain ASCII data in FBA format. The typical open-systems device emulation type is OPEN-V.

DEVNdevice number

DFWDASD fast write

DHCPdynamic host configuration protocol

differential dataChanged data in the primary volume not yet reflected in the copy.

disaster recoveryA set of procedures to recover critical application data and processing after a disaster or other failure.

disk arrayDisk array, or just array, is another name for a RAID storage system.

disk controller (DKC)The hardware component that manages front-end and back-end storage operations. The term DKC can refer to the RAID storage system.

DKCdisk controller. Can refer to the RAID storage system or the controller components.

DKCMAINdisk controller main. Refers to the microcode for the RAID storage system.

DKPdisk processor. Refers to the microprocessors on the back-end director features of the Universal Storage Platform V

DKUdisk unit. Refers to the cabinet (floor model) or rack-mounted hardware component that contains data drives and no controller components.



Glossary–8

DMPDynamic Multi Pathing

DRUHitachi Data Retention Utility

DP-VOLDynamic Provisioning-virtual volume. A virtual volume where Dynamic Provisioning is not using memory space.

dynamic provisioningAn approach to managing storage. Instead of “reserving” a fixed amount of storage, the host removes capacity from the available pool at the time data is written to disk. Also called thin provisioning.

E

ECerror code

emulationThe operation of the Hitachi RAID storage system to emulate the characteristics of a different storage system. For device emulation the mainframe host “sees” the logical devices on the RAID storage system as 3390-x devices. For controller emulation the mainframe host “sees” the control units (CUs) on the RAID storage system as 2105 or 2107 controllers.

RAID storage system operates the same as the storage system being emulated.

emulation groupA set of device emulation types that can be intermixed within a RAID group and treated as a group.

env.environment

ERCerror reporting communications

ESCONEnterprise System Connection



EXCTGSee extended consistency group (ECTG).

EXGexternal volume group

ext.external

extended consistency group (EXCTG)A set of Universal Replicator for Mainframe journals in which data consistency is guaranteed. When you perform copy operations between multiple primary and secondary systems, the journals must be registered in an EXCTG.

external applicationA software module a storage system is using but runs on a separate platform.

external portA fibre-channel port that is configured to be connected to an external storage system for Universal Volume Manager operations.

external volumeA logical volume whose data resides on drives that are physically located outside the Hitachi storage system.

F

failbackThe process of switching operations from the secondary path or host back to the primary path or host, after the primary path or host has recovered from failure. See also failover.

failoverThe process of switching operations from the primary path or host to a secondary path or host when the primary path or host fails.

FBAfixed-block architecture

FCfibre channel; FlashCopy



Glossary–10

FCAfibre-channel adapter

FC-ALfibre-channel arbitrated loop

FCIPfibre-channel internet protocol

FCPfibre-channel protocol

FCSPfibre-channel security protocol

FIBARCFibre Connection Architecture

FICONFibre Connectivity

FIFOfirst in, first out

free capacityThe amount of storage space (in bytes) that is available for use by the host system.

FSWfibre switch

FTPfile-transfer protocol

FVfixed-size volume

FWDfast-wide differential



G

GIDgroup ID

GUIgraphical user interface

H

HAhigh availability

HACMPHigh Availability Cluster Multi-Processing

HAMHitachi High Availability Manager

HDLMHitachi Dynamic Link Manager

HDPHitachi Dynamic Provisioning

HDSHitachi Data Systems

HDTHitachi Dynamic Tiering

HDvMHitachi Device Manager

HGLAMHitachi Global Link Availability Manager

H-LUNhost logical unit

HOMRCFHitachi Open Multi-RAID Coupling Feature. Another name for Hitachi ShadowImage.



Glossary–12

HORCHitachi Open Remote Copy. Another name for Hitachi TrueCopy.

HORCMHitachi Open Remote Copy Manager. Another name for Command Control Interface.

host failoverThe process of switching operations from one host to another host when the primary host fails.

host groupA group of hosts of the same operating system platform.

host modeOperational modes that provide enhanced compatibility with supported host platforms. Used with fibre-channel ports on RAID storage systems.

host mode optionAdditional options for fibre-channel ports on RAID storage systems. Provide enhanced functionality for host software and middleware.

HRCHitachi Remote Copy. Another name for Hitachi TrueCopy for IBM z/OS.

HRpMHitachi Replication Manager

HSCSHitachi Storage Command Suite. This suite of products is now called the Hitachi Command Suite.

HURHitachi Universal Replicator

HXRCHitachi Extended Remote Copy. Another name for Hitachi Compatible Replication for IBM XRC.

I

iFCPinternet fibre-channel protocol



IMLinitial microcode load; initial microprogram load

IMPLinitial microprogram load

initial copyAn initial copy operation is performed when a copy pair is created. Data on the primary volume is copied to the secondary volume.

initiator portA fibre-channel port configured to send remote I/Os to an RCU target port on another storage system. See also RCU target port and target port.

in-system replicationThe original data volume and its copy are located in the same storage system. ShadowImage in-system replication provides duplication of logical volumes; Copy-on-Write Snapshot in-system replication provides “snapshots” of logical volumes that are stored and managed as virtual volumes (V-VOLs).

See also remote replication.

intermediate site (I-site)A site that functions as both a TrueCopy secondary site and a Universal Replicator primary site in a 3-data-center (3DC) cascading configuration.

internal volumeA logical volume whose data resides on drives that are physically located within the storage system. See also external volume.

IO, I/Oinput/output

IOPSI/Os per second

IPinternet protocol

IPLinitial program load



Glossary–14

J

JNLjournal

JNLGjournal group

journal group (JNLG)In a Universal Replicator system, journal groups manage data consistency between multiple primary volumes and secondary volumes. See also consistency group (CTG).

journal volumeA volume that records and stores a log of all events that take place in another volume. In the event of a system crash, the journal volume logs are used to restore lost data and maintain data integrity.

In Universal Replicator, differential data is held in journal volumes on until it is copied to the S-VOL.

JREJava Runtime Environment

L

L1 pairSee layer-1 (L1) pair.

L2 pairSee layer-2 (L2) pair.

LANlocal-area network

layer-1 (L1) pairIn a ShadowImage cascade configuration, a layer-1 pair consists of a primary volume and secondary volume in the first cascade layer. An L1 primary volume can be paired with up to three L1 secondary volumes. See also cascade configuration.

layer-2 (L2) pairIn a ShadowImage cascade configuration, a layer-2 (L2) pair consists of a primary volume and secondary volume in the second cascade layer. An



L2 primary volume can be paired with up to two L2 secondary volumes. See also cascade configuration.

LBAlogical block address

LCPlocal control port; link control processor

LCUlogical control unit

LDEVlogical device

LDKCSee logical disk controller (LDKC).

leaf volumeA level-2 secondary volume in a ShadowImage cascade configuration. The primary volume of a layer-2 pair is called a node volume. See also cascade configuration.

LEDlight-emitting diode

license keyA specific set of characters that unlocks an application and allows it to be used.

local copySee in-system replication.

local siteSee primary site.

logical device (LDEV)An individual logical data volume (on multiple drives in a RAID configuration) in the storage system. An LDEV may or may not contain any data and may or may not be defined to any hosts. Each LDEV has a unique identifier or “address” within the storage system composed of the logical disk controller (LDKC) number, control unit (CU) number, and LDEV number. The LDEV IDs within a storage system do not change.An LDEV formatted for use by mainframe hosts is called a logical volume



Glossary–16

image (LVI). An LDEV formatted for use by open-system hosts is called a logical unit (LU).

logical disk controller (LDKC)A group of 255 control unit (CU) images in the RAID storage system that is controlled by a virtual (logical) storage system within the single physical storage system. For example, the Universal Storage Platform VM storage system supports two LDKCs, LDKC 00 and LDKC 01.

logical unit (LU)A logical volume that is configured for use by open-systems hosts (for example, OPEN-V).

logical unit (LU) pathThe path between an open-systems host and a logical unit.

logical volumeSee volume.

logical volume image (LVI)A logical volume that is configured for use by mainframe hosts (for example, 3390-9).

LUlogical unit

LUNlogical unit number

LUNMHitachi LUN Manager

LUSEHitachi LUN Expansion; Hitachi LU Size Expansion

LVlogical volume

M

main control unit (MCU)A storage system at a primary or main site that contains primary volumes of TrueCopy for Mainframe remote replication pairs. The MCU is configured to send remote I/Os to one or more storage systems at the secondary or remote site, called remote control units (RCUs), that



contain the secondary volumes of the remote replication pairs. See also remote control unit (RCU).

main siteSee primary site.

main volume (M-VOL)A primary volume on the main storage system in a TrueCopy for Mainframe copy pair. The M-VOL contains the original data that is duplicated on the remote volume (R-VOL). See also remote volume (R-VOL).

master journal (M-JNL)Holds differential data on the primary Universal Replicator system until it is copied to the restore journal (R-JNL) on the secondary system. See also restore journal (R-JNL).

max.maximum

MBmegabyte

Mb/sec, Mbpsmegabits per second

MB/sec, MBpsmegabytes per second

MCUSee main control unit (MCU).

MF, M/Fmainframe

MIHmissing interrupt handler

mirrorIn Universal Replicator, each pair relationship in and between journals is called a “mirror”. During pair creation, each pair is assigned a mirror ID. This ID identifies individual pair relationships between journals.

M-JNLmain journal



Glossary–18

modify modeThe mode of operation of Storage Navigator that allows changes to the storage system configuration. See also view mode.

MPmicroprocessor

MSCSMicrosoft Cluster Server

mto, MTOmainframe-to-open

MUmirror unit

multi-pathingA performance and fault-tolerant technique that uses more than one physical connection between the storage system and host system. Also called multipath I/O.

M-VOLmain volume

N

node volumeA level-2 primary volume in a ShadowImage cascade configuration. The secondary volume of a layer-2 pair is called a leaf volume. See also cascade configuration.

NUMnumber

NVSnonvolatile storage

O

OPEN-VA logical unit (LU) of user-defined size that is formatted for use by open-systems hosts.



OPEN-xA logical unit (LU) of fixed size (for example, OPEN-3 or OPEN-9) that is used primarily for sharing data between mainframe and open-systems hosts using Hitachi Cross-OS File Exchange.

OSoperating system

OS/390Operating System/390

P

pairTwo logical volumes in a replication relationship in which one volume contains original data to be copied and the other volume contains the copy of the original data. The copy operations can be synchronous or asynchronous, and the pair volumes can be located in the same storage system (in-system replication) or in different storage systems (remote replication).

pair statusIndicates the condition of a copy pair. A pair must have a specific status for specific operations. When an operation completes, the status of the pair changes to the new status.

parity groupSee RAID group.

path failoverThe ability of a host to switch from using the primary path to a logical volume to the secondary path to the volume when the primary path fails. Path failover ensures continuous host access to the volume in the event the primary path fails.

See also alternate path and failback.

PGparity group. See RAID group.

physical deviceSee device.

PiTpoint-in-time



Glossary–20

point-in-time (PiT) copyA copy or snapshot of a volume or set of volumes at a specific point in time. A point-in-time copy can be used for backup or mirroring application to run concurrently with the system.

poolA set of volumes that are reserved for storing Copy-on-Write Snapshot data or Dynamic Provisioning write data.

pool volume (pool-VOL)A logical volume that is reserved for storing snapshot data for Copy-on-Write Snapshot operations or write data for Dynamic Provisioning.

port attributeIndicates the type of fibre-channel port: target, RCU target, or initiator.

port blockA group of four fibre-channel ports that have the same port mode.

port modeThe operational mode of a fibre-channel port. The three port modes for fibre-channel ports on the Hitachi RAID storage systems are standard, high-speed, and initiator/external MIX.

PPRCPeer-to-Peer Remote Copy

Preview listThe list of requested operations on Storage Navigator.

primary siteThe physical location of the storage system that contains the original data to be replicated and that is connected to one or more storage systems at the remote or secondary site through remote copy connections. A primary site can also be called a “main site” or “local site”.

The term “primary site” is also used for host failover operations. In that case, the primary site is the host computer where the production applications are running, and the secondary site is where the backup applications run when the applications at the primary site fail, or where the primary site itself fails.



primary volumeThe volume in a copy pair that contains the original data to be replicated. The data in the primary volume is duplicated synchronously or asynchronously on the secondary pairs.

The following Hitachi products use the term P-VOL: Storage Navigator, Copy-on-Write Snapshot, ShadowImage, ShadowImage for Mainframe, TrueCopy, Universal Replicator, Universal Replicator for Mainframe, and High Availability Manager.

See also secondary volume (S-VOL).

P-siteprimary site

P-VOLTerm used for the primary volume in the earlier version of the Storage Navigator GUI (still in use). See primary volume.

Q

quick formatThe quick format feature in Virtual LVI/Virtual LUN in which the formatting of the internal volumes is done in the background. This allows system configuration (such as defining a path or creating a TrueCopy pair) before the formatting is completed. To run quick formatting, the volumes must be in blocked status.

quick restoreA reverse resynchronization in which no data is actually copied: the primary and secondary volumes are swapped.

quick splitA split operation in which the pair becomes split immediately before the differential data is copied to the secondary volume (S-VOL). Any remaining differential data is copied to the S-VOL in the background. The benefit is that the S-VOL becomes immediately available for read and write I/O.

R

R/W, r/wread/write

RAIDredundant array of inexpensive disks



Glossary–22

RAID groupA redundant array of inexpensive drives (RAID) that have the same capacity and are treated as one group for data storage and recovery. A RAID group contains both user data and parity information, which allows the user data to be accessed in the event that one or more of the drives within the RAID group are not available. The RAID level of a RAID group determines the number of data drives and parity drives and how the data is “striped” across the drives. For RAID1, user data is duplicated within the RAID group, so there is no parity data for RAID1 RAID groups.

A RAID group can also be called an array group or a parity group.

RAID levelThe type of RAID implementation. RAID levels include RAID0, RAID1, RAID2, RAID3, RAID4, RAID5 and RAID6.

RCPremote control port

RCUSee remote control unit (RCU).

RDread

RCU target portA fibre-channel port that is configured to receive remote I/Os from an initiator port on another storage system.

remote console PCA previous term for the personal computer (PC) system that is LAN-connected to a RAID storage system. The current term is Storage Navigator PC.

remote control port (RCP)A serial-channel (ESCON) port on a TrueCopy main control unit (MCU) that is configured to send remote I/Os to a TrueCopy remote control unit (RCU).

remote control unit (RCU)A storage system at a secondary or remote site that is configured to receive remote I/Os from one or more storage systems at the primary or main site.

remote copySee remote replication.



remote copy connectionsThe physical paths that connect a storage system at the primary site to a storage system at the secondary site. Also called data path.

remote replicationData replication configuration in which the storage system that contains the original data is at a local site and the storage system that contains the copy of the original data is at a remote site. TrueCopy and Universal Replicator provide remote replication. See also in-system replication.

remote siteSee secondary site.

remote volume (R-VOL)In TrueCopy for Mainframe, a volume at the remote site that contains a copy of the original data on the main volume (M-VOL) at the main site.

restore journal (R-JNL)Holds differential data on the secondary Universal Replicator system until it is copied to the secondary volume.

resync“Resync” is short for resynchronize.

RFrecord format

RIOremote I/O

R-JNLrestore journal

RLrecord length

RMIRemote Method Invocation

rndrandom



Glossary–24

root volumeA level-1 primary volume in a ShadowImage cascade configuration. The secondary volume of a layer-1 pair is called a node volume. See also cascade configuration.

RPOrecovery point objective

R-SIMremote service information message

R-siteremote site (used for Universal Replicator)

RTCreal-time clock

RTOrecovery time objective

R-VOLSee remote volume (R-VOL).

R/Wread/write

S

S#serial number

S/Nserial number

s/wsoftware

SAIDsystem adapter ID

SANstorage-area network



SATAserial Advanced Technology Attachment

SCstorage control

SCDSsource control dataset

SCIstate change interrupt

scriptingThe use of command line scripts, or spreadsheets downloaded by Configuration File Loader, to automate storage management operations.

SCSIsmall computer system interface

secondary siteThe physical location of the storage system that contains the primary volumes of remote replication pairs at the main or primary site. The storage system at the secondary site is connected to the storage system at the main or primary site through remote copy connections. The secondary site can also be called the “remote site”.

See also primary site.

secondary volumeThe volume in a copy pair that is the copy. The following Hitachi products use the term “secondary volume”: Thin Image, Copy-on-Write Snapshot, ShadowImage, ShadowImage for Mainframe, TrueCopy, Universal Replicator, Universal Replicator for Mainframe, High Availability Manager, and Hitachi Compatible Replication for IBM® XRC.

See also primary volume.

seq.sequential

service information message (SIM)SIMs are generated by a RAID storage system when it detects an error or service requirement. SIMs are reported to hosts and displayed on Storage Navigator.



Glossary–26

service processor (SVP)The computer inside a RAID storage system that hosts the Storage Navigator software and service personnel for configuration and maintenance of the storage system is using.

severity levelApplies to service information messages (SIMs) and Storage Navigator error codes.

SIHitachi ShadowImage

SIzShadowImage for Mainframe

sidefileAn area of cache memory that is used to store updated data for later integration into the copied data.

SIMservice information message

sizeGenerally refers to the storage capacity of a memory module or cache. Not usually used for storage of data on disk or flash drives.

SMshared memory

SMTPsimple mail transfer protocol

SNserial number shown in Storage Navigator

snapshotA point-in-time virtual copy of a Copy-on-Write Snapshot primary volume (P-VOL). The snapshot is maintained when the P-VOL is updated by storing pre-updated data (snapshot data) in a data pool.

SNMPsimple network management protocol



SOMsystem option mode

source volume (S-VOL)The volume in a mainframe local copy pair containing the original data. This term is used only for the following Hitachi products: ShadowImage for Mainframe, Compatible FlashCopy® V2, and Dataset Replication.

spaceGenerally refers to the data storage capacity of a disk drive or flash drive.

SRMStorage Replication Manager

SSsnapshot

SSBsense byte

SSID(storage) subsystem identifier. SSIDs are used as an additional way to identify a control unit on mainframe operating systems. Each group of 64 or 256 volumes requires one SSID, therefore there can be one or four SSIDs per CU image. For the VSP storage system, one SSID is associated with 256 volumes.

SSLsecure socket layer

steady splitIn ShadowImage, a typical pair split operation in which any remaining differential data from the P-VOL is copied to the S-VOL and then the pair is split.

S-VOLSee secondary volume or source volume (S-VOL). When used for “secondary volume”, “S-VOL” is only seen in the earlier version of the Storage Navigator GUI (still in use).

SVPSee service processor (SVP).



Glossary–28

syncsynchronous

system option mode (SOM)Additional operational parameters for the RAID storage systems that enable the storage system to be tailored to unique customer operating requirements. SOMs are set on the service processor.

T

target portA fibre-channel port that is configured to receive and process host I/Os.

target volume (T-VOL)The volume in a mainframe copy pair that is the copy. The term is used only in the earlier version of the Storage Navigator GUI (still in use), for the following Hitachi products: ShadowImage for Mainframe, Dataset Replication, Compatible FlashCopy® V2.

See also source volume (S-VOL).

TBterabyte

TCHitachi TrueCopy

TCzHitachi TrueCopy for Mainframe

TDEVNtarget device number

TGTtarget; target port

THDthreshold

TIDtarget ID

total capacityThe aggregate amount of storage space in a data storage system.



T-VOLSee target volume (T-VOL).

U

update copyAn operation that copies differential data on the primary volume of a copy pair to the secondary volume. Update copy operations are performed in response to write I/Os on the primary volume after the initial copy operation is completed.

URHitachi Universal Replicator

URzHitachi Universal Replicator for Mainframe

USPHitachi TagmaStore® Universal Storage Platform

USP VHitachi Universal Storage Platform V

USP VMHitachi Universal Storage Platform VM

UTUniversal Time

UTCUniversal Time-coordinated

V

Vversion; variable length and de-blocking (mainframe record format)

VBvariable length and blocking (mainframe record format)

view modeThe mode of operation of Storage Navigator that allows viewing only of the storage system configuration. The two Storage Navigator modes are view mode and modify mode.



Glossary–30

virtual device (VDEV)A group of logical devices (LDEVs) in a RAID group. A VDEV typically consists of some fixed volumes (FVs) and some free space. The number of fixed volumes is determined by the RAID level and device emulation type.

Virtual LVI/LUN volumeA custom-size volume whose size is defined by the user using Virtual LVI/Virtual LUN. Also called a custom volume (CV).

virtual volume (V-VOL)The secondary volume in a Thin Image or Copy-on-Write Snapshot pair. When in “PAIR” status, the V-VOL is an up-to-date virtual copy of the primary volume (P-VOL). When in “SPLIT” status, the V-VOL points to data in the P-VOL and to replaced data in the pool, maintaining the point-in-time copy of the P-VOL at the time of the split operation.

When a V-VOL is used with Dynamic Provisioning, it is called a DP-VOL.

VLLHitachi Virtual LVI/LUN

VLVIHitachi Virtual LVI

VMvolume migration; volume manager

VOL, volvolume

VOLIDvolume ID

volservolume serial number

volumeA logical device (LDEV), or a set of concatenated LDEVs in the case of LUSE, that has been defined to one or more hosts as a single data storage unit. A mainframe volume is called a logical volume image (LVI), and an open-systems volume is called a logical unit. (LU).

volume pairSee copy pair.



V-VOLvirtual volume

V-VOL management areaContains the pool management block and pool association information for Copy-on-Write Snapshot operations. The V-VOL management area is created automatically when additional shared memory is installed and is required for Copy-on-Write Snapshot operations.

W

WANwide-area network

WDMwavelength division multiplexing

WRwrite

write orderThe order of write I/Os to the primary volume of a copy pair. The data on the S-VOL is updated in the same order as on the P-VOL, particularly when there are multiple write operations in one update cycle. This feature maintains data consistency at the secondary volume. Update records are sorted in the cache at the remote system to ensure proper write sequencing.

WSworkstation

WWNworldwide name

WWPNworldwide port name

X

XRCIBM Extended Remote Copy



Glossary–32

Index–1Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot User Guide

Index

Aadditional shared memory 2–7At-Time Split operation 5–10

Bblocked pool

recovering 7–6troubleshooting 7–2

blocked volume 7–3

CCCI 1–6

command device 3–5troubleshooting with 7–8

consistency group, monitoring 6–4creating

multiple pairs in consistency group C–3pairs 5–3, C–2pools 3–2V-VOLs 3–4

Ddeleting

pairs 5–12, C–5pool data 5–11pools 6–8snapshot data 5–11

Dynamic Provisioning 4–4

Eexternal volumes, planning 2–16

HHistory window (secondary) E–6host access problem 7–4HP-UX server restriction 2–4

Iinteroperability 4–2

Llicense information, viewing 6–2, D–6

Mmanaging pools and V-VOLs 6–6maximum pairs, calculating 2–7monitoring pool information 6–5

Ooverview 1–2

Ppair

configuration 5–3details, viewing 6–3, D–3operations history, monitoring 6–4, D–8operations workflow 5–2restore problem 7–6split operation 5–10status definitions 6–2status for CCI operations A–2status monitoring 6–2, D–2tables 2–12

pairsdescription 1–2how many needed 2–7maximum number 2–7

pool capacity, increasing 6–6pool information, monitoring 6–5pool threshold exceeded 7–2pools

changing the usage threshold 6–7creating 3–2deleting 6–8description 1–4increasing capacity 6–6managing 6–6maximum number 2–3monitoring 6–5recovering 6–8requirements, restrictions 2–4


Index–2

sizing 2–5powering off the system 6–10

RRAID levels supported 2–3recovering a pool 6–8required shared memory 2–2requirements 2–2restoring a pair 5–11, C–5resynchronizing a pair 5–11, C–4

SS-VOL 1–2shared memory, V-VOL management area 2–9SIMs for pool problems 7–7Snapshot

installing, uninstalling 3–2overview 1–2powering off the system 6–10requirements 2–2

splitting pairs 5–9, C–4Storage Navigator 1–5synchronous rate, viewing 6–4

VV-VOL and S-VOL 1–2V-VOLs

creating 3–4deleting 6–9managing 6–8sizing 2–5

Volume Migration 4–9

MK-90RD7013-11

Hitachi Data Systems

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Hitachi Virtual Storage Platform · Hitachi Virtual Storage Platform Hitachi Copy-on-Write Snapshot...

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