Adm Snap

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EMC SnapView and Admsnap SnapView Version 02.03.5.022 and

Admsnap Version 02.03.004

Release Notes P/N 300-002-132

REV A01 December 15, 2004

These release notes contain supplemental information about the following EMC products:

SnapView™ version 02.03.5.022 and admsnap version 02.03.004.

EMC® Navisphere® SnapView user interface (UI) version 6.6.0. Please read these release notes completely before installing or using the software.

Topics include

Product Descriptions ................................................................................. 2 New Features and Changes...................................................................... 3 Environment and System Requirements ................................................ 4 Installation Notes ....................................................................................... 5 Issues Fixed in This Release...................................................................... 6 Known Problems and Limitations........................................................... 8 Technical Notes ........................................................................................ 14 Documentation......................................................................................... 29 Documentation Updates ......................................................................... 29 Software Media ........................................................................................ 31 Special Installation Instructions ............................................................. 31 Troubleshooting and Getting Help........................................................ 32

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Product Descriptions

EMC SnapView and Admsnap Release Notes

Product Descriptions

SnapView

EMC SnapView™ is a storage-system-based software application that allows you to create a copy of a LUN by using either clones or snapshots. You can use the clone or snapshot for decision support, system backups, data modeling, software application testing, or as a base for temporary operations on the production data without damaging the original data on the source LUN.

A clone is an actual copy of a LUN and it takes time to create. A snapshot is a virtual point-in-time copy of a LUN and takes only seconds to create. Depending on your application needs, you can create clones, snapshots and snapshots of clones.

Admsnap

The admsnap program runs on host systems in conjunction with SnapView in the SPs, and lets you start, activate, deactivate, and stop SnapView sessions. All admsnap commands are sent to the SP through the Fibre Channel bus.

The admsnap utility is an executable program that you can run interactively or via script.

For all Microsoft Windows® and UNIX® platforms, flush cached data from the host before you start a session. Failure to do this will result in an inconsistent or unusable point-in-time copy.

The admsnap clone commands can activate and deactivate a clone, and, for a Windows platform, flush data from a source LUN to its clone, bringing the source and clone into the synchronized state.

SnapView Rollback

SnapView rollback is a feature that allows the system administrator to “unsnap” a SnapView source LUN, instantly restoring its contents from a different point-in-time version. Any persistent SnapView session can be rolled back, in a way that appears instantaneous to host computers, without destroying any of the source LUNs sessions or snapshots. The production host's view of source LUN contents changes immediately, though actual data copying back to source LUNs runs invisibly in the background at a user-controllable speed.

The source LUNs that are the target of a rollback operation remain accessible and accept host I/O during and after the rollback; any new

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New Features and Changes


data written from the host supersedes data being rolled back from the session.

A rollback operation is non-destructive: the source LUNs’ other sessions are unaffected by the rollback and can still be accessed via their snapshot LUNs. The session being rolled back is also unaffected, except that any snapshot associated with it becomes temporarily inaccessible to host I/O for the duration of the rollback operation.

CLARiiON VSS Hardware Provider

Included with this software is the CLARiiON® Hardware Provider for Microsoft’s Volume Shadow Copy Service on Microsoft Windows Server™ 2003. The implementation of this hardware provider allows a Windows Server 2003 application, using the VSS API, to create/manage SnapView snapshots and SnapView clones on CLARiiON Fibre Channel storage systems without the explicit use of traditional CLARiiON user interfaces such as SnapView admsnap and/or Navisphere® software.

VSS is part of Microsoft’s storage initiative for Windows Server 2003. VSS provides coordination between writers, requestors, and providers. Writers are applications that can write to volumes and participate in the shadow copy synchronization process. Requestors initiate the creation and destruction of shadow copies. Providers own the shadow copy data and enable host access to the shadow copies.

New Features and Changes

This release contains cumulative changes to the SnapView 02.03.5.022 software release. These changes include the following:

Support for new CLARiiON CX300, CX500, and CX700 storage systems. The SnapView UI is pre-installed on all of these systems.

SnapView has added support for incremental SAN Copy™ software (SAN Copy v02.00.001 or higher).

The version numbering scheme for the SnapView and admsnap software has changed to include leading zeros. For example, Version 2.3 is now referred to as Version 02.03.xxx.

For information on how the new version numbering scheme affects the documentation, refer to the Documentation Updates section.

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Environment and System Requirements


Environment and System Requirements

This section identifies the hardware and software supported by SnapView 02.03.5.022 .

Hardware

SnapView software is supported on CX300, CX400, CX500, CX600, CX700 and FC4700-Series storage systems only. Admsnap is supported on a host running any of the following operating systems: IBM AIX®, Hewlett Packard HP-UX®, SGI IRIX®, Linux®, Novell NetWare®, Sun Solaris™, Windows® 2000, Windows NT®, or Windows Server™ 2003.

Storage-System Software

The following table lists the revisions of Access Logix™ software that are compatible with this release.

Storage-System Type Access Logix Software

CX700 02.06.700.5.xxx or higher





FC4700-Series 8.51.5x or higher

Operating Systems

Please refer to the EMC Support Matrix for a complete listing of operating systems supported by SnapView, VSS, and admsnap.

Navisphere Management Software

This release of SnapView and admsnap is compatible with the following versions of EMC Navisphere Management Software:

Navisphere Host Agent 6.6.0.x.x Navisphere CLI 6.6.0.x.x Navisphere Manager 6.6.0.x.x Navisphere SP Agent 6.6.0.x.x

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Installation Notes


Installation Notes

SnapView

The SP names of the CLARiiON array must be unique for the NDU of the SnapView software to be successful.


Windows Server 2003 32-bit must be installed on every system where the Provider is installed.

Make sure that Navisphere CLI version 6.6.X is installed on the server in the default location.

The administrator must set up a global user account for SYSTEM (all capitals) on all arrays that are attached to the host.

Install the CLARiiON VSS Hardware Provider on a Windows Server 2003 host by executing the CLARiiON VSS Provider InstallShield Package on your software media. The administrator will be asked to supply the password for the SYSTEM global user account that was set up for the domain of CLARiiON® arrays that are attached to the host.

Support for Differential (SnapCopy Copy-On-First-Write) Shadow Copies requires SnapView storage-system software to be installed and sufficient snapshot cache to be configured.

Support for Plex (SnapView clone) Shadow Copies requires SnapView, Navisphere CLI Provider, and Navisphere SnapView Clone Provider array software to be installed. This support also requires that any Shadow Copied Source LUN and its clone(s) be in an existing Clone Group.

Create a file named C:\Program Files\EMC\Navisphere CLI\ClariionSPAddress that contains the IP addresses of the CLARiiON Storage Processors on separate lines for array1 through arrayN as shown in the following example.

<array1 SP A’s IP address> <array1 SP B’s IP address> . . . <arrayN SP A’s IP address> <arrayN SP B’s IP address>

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Issues Fixed in This Release



Problem Description Detail

AIX Admsnap: AIX does not guarantee that all of the buffers are flushed with the sync; sync; sync; command sequence. This requires that fsck be run on the clone after it is fractured before it can be mounted on the backup host. [87316]

Frequency of occurrence: Frequently Effect: The activated SnapView session will require the LUN(s) to be repaired with fsck. Prevention/Resolution: IBM supports the current recommendation to create a separate JFSLOG file for each file system instead of one for each volume group.

Windows 2000 Admsnap: Admsnap activate will fail if the associated volume is deported prior to deactivating the session. [87262]

Frequency of occurrence : Frequently Effect: The subsequent activate will fail after a volume group is deported and deactivated. Prevention/Resolution: Admsnap deactivate has been modified to properly deactivate a session if the physical devices do not contain Windows logical volumes.

Windows 2000 and Windows Server 2003 Admsnap: Admsnap returns an error level of 0, even in failing situations. [87667]

Frequency of occurrence : Frequently Effect: The command output needs to be examined or parsed to determine if the command was successful. Prevention/Resolution: Admsnap has been modified to set the error level to a non-zero value in failing situations.

Windows 2000 and Windows Server 2003 Admsnap: Windows 2000 and Windows Server 2003 may retain filesystem structures when using admsnap. [90554, 91627, 92789]

Frequency of occurrence : Infrequently Effect: An activated SnapView Clone or SnapShot may present some of the filesystem structure from the previous session/activation. Prevention/Resolution: Admsnap deactivate has been modified to ensure the volume is removed from the operating system and all filesystem data structures are discarded.

Admsnap (all Platforms): Stopping a SnapView session and immediately starting a session using the same session name may cause the SP to bugcheck. [94152, 91251]

Frequency of occurrence : Infrequently Effect: An SP may bugcheck and reboot. Prevention/Resolution: This issue has been addressed in SnapView 2.20.0. Prior to Release 2.20.0, a small delay is needed between stopping and starting of the session if the same session name is used. This applies only if the session stopped is not the last session on the source LUNs).

SnapView: SnapView may bugcheck if the source LUN is faulted. [116838]

Frequency of occurrence : Infrequently Effect: An SP may bugcheck and reboot. Prevention/Resolution: This issue has been addressed.

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SnapView: SnapView Incremental session will not stop on I/O errors to the reserved LUN pool. [113188].

Frequency of occurrence : Infrequently Effect: A Incremental SAN Copy session will not terminate when it should. Prevention/Resolution: This issue has been addressed

SnapView: SnapView Clones may leak memory on a trespass event.. [115797]

Frequency of occurrence : Infrequently Effect: The SP may reboot due to a memory exhaustion condition. Prevention/Resolution: This issue has been addressed

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Known Problems and Limitations



This section contains information and/or limitations that could adversely affect the performance of the storage system if any listed work-around or fixes are not implemented.

Generic Problems (Apply to All Platforms)


SnapView Clones and SAN Copy. Adding a clone to a Clone Group whose source is the destination of an active SAN Copy session may hang the SAN Copy session. [90823]

Frequency of occurrence: Frequent Prevention/Resolution: The SP on which the session is stuck must be rebooted to clear this condition.

SnapView Clones and SAN Copy. Navisphere CLI and Manager return an error message while creating a Clone Group. [77906]

Frequency of occurrence: Always (If selected LUN was previously part of a SAN Copy session, this will always occur.) Effect: The software returns the following error while creating Clone Group: Creating Clone Group failed. Error occurred while adding Clone driver to LUN’s extended attributes.

This error could mean (among other things) that the LUN is, or was once, part of a SAN Copy session. Prevention/Resolution: Use the Navisphere CLI setfeature command to remove the SAN Copy feature from the LUN.

SnapView Clones. Unbinding a faulted clone private LUN without deallocating or reallocating the clone private LUN will lead to serious problems after the next reboot. [83994]

Frequency of occurrence: Very infrequent Prevention/Resolution: You can prevent this by reallocating or deallocating the faulted clone private LUNs before unbinding them. You should perform the reallocation or deallocation before the next reboot.

SnapView Clones. A synchronization operation gets stuck in the Queued to be Synchronized condition. [83018, 91758]

Frequency of occurrence: Very infrequent Prevention/Resolution: To recover, reboot the SP on which the synchronization is stuck. If you set the Recovery Policy to Manual, an explicit synchronization initiation will be needed to start the synchronization again.

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SnapView Clones. You can perform only a maximum of 4 concurrent synchronizations or reverse synchronizations per SP, as opposed to 20, as stated in the manual. This restriction may be lifted in a future SnapView release. [75009, 76558]

Frequency of occurrence: Always Effect: If you start more than 4 synchronizations and/or reverse synchronizations, the software queues the remainder. Prevention/Resolution: N/A.

SnapView. Once you remove a LUN from the SnapView reserved LUN pool, it is unowned. [75223]

Frequency of occurrence: Whenever a LUN is removed from the SnapView reserved LUN pool. Effect: The LUNs are unowned, and the LUN must be trespassed to allow an SP to take ownership of the LUN. Prevention/Resolution: To start using a LUN that has been removed from the SnapView reserved LUN pool: 1. The LUN must be explicitly trespassed using Navisphere

which forces an SP to take ownership of a LUN. 2. Add the LUN to the attached hosts Storage Group. The LUN can now be accessed by the attached host .

SnapView. When the storage system terminates a SnapView session due to an unexpected event (trespass, save area exhaustion, and so on), a warning message is not posted to the management station. [59416]

Frequency of occurrence: Always Effect: When the system ends a SnapView session, Navisphere Manager will display offline next to the SnapView session's icon in the Enterprise window. Prevention/Resolution: Check the SP Event Log to determine the cause of the termination of the SnapView session.

SnapView with MirrorView™ software. A SnapView session cannot be started and a snapshot cannot be created on a MirrorView secondary image LUN during the synchronization of the image. [67991]

Frequency of occurrence: Always Effect: The operation fails and the command must be retried after the synchronization completes. The software produces two distinct error messages (one for starting a session, and one for creating a snapshot). Prevention/Resolution: Starting a session or creating a snapshot on a MirrorView LUN that does not currently have a snapshot will cause a restacking of the device to insert SnapView, which is not allowed during a MirrorView synchronization.

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SnapView. The listing of the SnapView save area statistics may display negative values. [78395]

Frequency of occurrence: Infrequently Effect: The save area usage statistics are inaccurate. Prevention/Resolution: Trespass the SnapView sessions to the original owning (default) SPs.

SnapView. Heavy I/O to a SnapView session may cause the storage system to respond slowly to Navisphere requests. [78394]

Frequency of occurrence: Infrequently Effect: The storage system responds slowly to Navisphere Management requests. Prevention/Resolution: When this has been observed, the SnapView source or snapshot save area LUNs were created on the PSM LUNs. Resolve this problem by creating the LUNs from a different RAID Group.

SnapView. SnapView persistent sessions may trespass when a Storage Processor is rebooted even if the attached host did not issue I/O requests to the sessions. [82215]

Frequency of occurrence: Infrequently Effect: The persistent session will trespass. Prevention/Resolution: The LUN(s) can be trespassed back to the default SP.

SnapView Rollback and Dynamic Disks. A SnapView session that contains a dynamic disk that is “rolled-back” to the production host using SnapView cannot be imported on the production host using admsnap. [88012]

Frequency of occurrence: Frequently Effect: Dynamic disks must be imported using the Disk Administrator or the Microsoft Diskpart utility. Prevention/Resolution: None at this time.

SnapView. SnapView save area LUNs may change state to “unowned” when the LCC for an enclosure is replaced. [91459]

Frequency of occurrence: Infrequently Effect: The SnapView save area LUNs for the peer SP would be displayed as “unowned.” Allocate the save area LUNs for each SP from different enclosures ,or trespass the unowned save area LUNs to the desired SP. Prevention/Resolution: None at this time.

SnapView. SnapView may bugcheck if a SnapView save area LUN cannot satisfy I/O requests. [93068]

Frequency of occurrence: Infrequently Effect: The Storage Processor that currently owns the source LUN for that session will bugcheck. Prevention/Resolution: None at this time.

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Platform-Specific Problems


Admsnap – AIX. Admsnap may fail to start a session on a source LUN that has trespassed on systems using ATF software. [88799]

Frequency of occurrence: Frequently Effect: The admsnap command may hang or take several minutes to complete. Prevention/Resolution; Use the Navisphere CLI to start the SnapView session.

Admsnap - Linux. Admsnap on a RedHat Linux 7.2 system will not activate more than seven LUNs.

Frequency of occurrence: Frequently Effect: Cannot access more than seven LUNs on the backup host. Prevention/Resolution: The Linux kernel creates only 8 SG devices by default. Additional SG devices must be created and then linked to the SD devices. (The internal disk uses one of the SG devices.)

SnapView - Veritas. SnapView save area usage may be significant when synchronizing a Veritas mirror.

[75026]

Frequency of occurrence: Always Effect: Snap View save area allocation is significant and may exhaust the save area for the Storage Processor. Prevention/Resolution: 1. On the production host unmount the file system and then start the

SnapView session using Navisphere CLI. 2. Make sure that the snapshot save area free capacity is larger (5%

larger should be sufficient) than the size of the Veritas mirror image. This is because the synchronization being done by the software on the second host will write the entire mirror and you will need the extra SnapView save area space to hold the data.

3. On the second host, once the snapshot has been imported to Veritas, break the mirror prior to letting Veritas start.

An alternative workaround is to create a snapshot save area LUN that is larger (5% larger should be sufficient) than the LUN you will mirror. This will avoid exhausting the snapshot reserved LUN pool.

Admsnap - Windows 2000 and Windows Server 2003. The admsnap activate command cannot assign a drive letter to a dynamic disk. [78222]

Frequency of occurrence: Infrequently Effect: Unable to import the dynamic drive volume. Prevention/Resolution: To import a dynamic disk on the backup host do the following: 1. Use the admsnap activate command to activate the session, for

example, admsnap activate -s sessionname 2. Once activated, reboot the backup host. 3. Then use Computer Management to import the foreign disk. 4. After the dynamic disk is imported, make sure a drive letter has been

assigned to the imported disk. 5. Run admsnap clone_activate to refresh the data on the disk.

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Admsnap - activate. Using the activate command when all available drive letters are allocated will result in admsnap reporting the SCSI device name for the devices [86526]

Frequency of occurrence: Always Effect: The SnapView session is activated and the user would need to access the LUNs via the SCSI device name of the LUN(s). Prevention/Resolution: Free up some of the drive letters.

Admsnap - Windows 2000 and Windows Server 2003. The admsnap activate command will display an erroneous warning message if the –o and –d options are used. [97668]

Frequency of occurrence: Frequently Effect: An erroneous warning message is generated for a successful operation. If the command line specifies –o <physical drive> -d X: (where X is a valid free drive letter), the activate command would succeed and the drive letter would be assigned, but the admsnap command would print a warning message that the drive letter was not assigned. Prevention/Resolution: None.

CLARiiON VSS Provider – Windows Server 2003. The CLARiiON Provider does not operate properly when using the Qlogic STORPort HBA driver with hotfix 5.2.3790.1014 installed. [89600]

Frequency of occurrence: Always Effect: The Provider software will return the error VSS_E_VOLUME_NOT_SUPPORTED Prevention/Resolution: Use the Microsoft STORPort hotfix 5.2.3790.5 with Qlogic HBAs.

CLARiiON VSS Provider – Windows Server 2003. Import fails using 4-digit LUN IDs [94551]

Frequency of occurrence: Frequently Effect: The Provider software will fail the Shadow Copy Import. Prevention/Resolution: None at this time.

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Configuration Limitations

The configuration guidelines for SnapView 02.03.5.022 are listed in the following table.

Parameter CX700, CX600, or FC4700 CX500 or CX400 CX300 Clones Per Storage System Per Source LUN

100 maximum (includes source LUN and Primary or Secondary MirrorView™ images) 8 maximum

50 maximum (includes source LUN and Primary or Secondary MirrorView images) 8 maximum


Clone Groups Per Storage System

50 maximum

25 maximum

25 maximum

Clone Private LUNs Per Storage System

2 required

2 required

2 required

Snapshotsa Per Storage System Per Source LUN

300 maximum 8 maximum



SnapView Sessionsa Per Source LUN

8 maximum

8 maximum

8 maximum

Reserved Pool LUNs Per Storage System

100 maximum

50 maximum

25 maximum

a. The limits for snapshots and sessions include SnapView snapshots or SnapView sessions and any reserved snapshots or reserved sessions used in another application such as SAN Copy.

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Technical Notes


Technical Notes

This section contains information that will help with the installation, use, and management of the storage system. It provides generic information that applies to all platforms and platform-specific information, except for Hewlett Packard Tru64 systems.

Generic Notes (Apply to All Platforms)

SnapView – SnapView sessions are created to support incremental SAN Copy sessions. These sessions count towards the eight-session limit for a source LUN.

SnapView – All persistent sessions on a source LUN that were created prior to Release 2.3 must be stopped before an incremental SAN Copy session can be created on that source LUN. Once all of the sessions are stopped on a source LUN, the SAN Copy session and SnapView sessions (persistent and non-persistent) can be started in any order.

SnapView – Persistent sessions. SnapView 2.0 supports persistent sessions, which survive host trespasses and SP reboots.

SnapView - Cache model. As of SnapView 1.3, the snapshot cache LUNs are dedicated on a per-source-LUN basis instead of on a per-SP basis. For details on how the caching model works and to determine an appropriate snapshot cache size, refer to the EMC SnapView Version 2.X Administrator's Guide for Navisphere 6.X (P/N 069001180).

SnapView - Upgrading. To ensure a correct and orderly upgrade process, the installation software sets the storage-system cache sizes to 0, and disables caching, as part of the software installation (NDU) process. After the upgrade, you must redefine the cache settings to appropriate values (possibly less than the previous values) and then enable caching.

SnapView Clones – If SnapView clones enter a degraded mode, you will have to reboot the SP to clear the condition.

SnapView Clones – Synchronization. On a CX400, you should perform clone synchronization operations using either a medium (which is the default) or slow synchronization rate.

SnapView Clones – Percent Synchronized value gets reset to 0% if a source LUN or a clone LUN is expanded when a sync or a reverse sync operation is in progress. The data previously synchronized or reverse synchronized is not re-synchronized if this happens.

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Technical Notes


SnapView – Memory budget and cache usage. SnapView revision 2.10.06 and later removes the limitation of the memory budget. This means SnapView can now exceed the capabilities of the memory budget, eliminating the cache LUN or Copy-On-First-Write upper limits. In other words, SnapView no longer imposes upper limits on the amount of data that can be modified on the source LUN. However, SnapView sessions must still have free/available cache space.

A session that is stopped will free the associated space used on all of the reserved LUNs that were allocated for that session. Once the last session on a source LUN(s) is stopped, the reserved LUNs will be returned to the reserved LUN pool.

SnapView - Statistics. The session statistics for I/O to the source and snapshot are not persistent and therefore are reset to 0 upon reboot or panic. This behavior is similar to the FLARE I/O statistics, which reset with every reboot. Note that cache statistics should be correct after a reboot, but session I/O statistics will reset to 0. [78941]

SnapView - LUN limit. For FC4700-Series storage systems, the total number of LUNs plus snapshot LUNs should not exceed 523 (223 LUNs are storage-system LUNs and 300 LUNs are snapshot LUNs). For a CX600 or CX700 storage systems, the total number of LUNs plus snapshot LUNs should not exceed 1324 LUNs (1024 LUNs are storage-system LUNs and 300 LUNs are snapshot LUNs). For a CX400 or CX500 storage system, the total number of snapshot LUNs should not exceed 150, and the total number of objects that can be put in Storage Groups is 662.

Neither of these values include the PSM LUN, which the software requires before using the application.

Neither the storage-system software nor Navisphere enforces these limits. If you exceed these limits, the following may happen:

• Some LUNs may be inaccessible to the host. • Attempts to fail over LUNs to the peer SP may not succeed,

causing the LUNs to be inaccessible.

Depending on the operating system, the system will react differently when you attempt to access an inaccessible LUN. For example, Novell NetWare® will fail to boot if any LUNs it expects to access are inaccessible.

SnapView - Chunk Size. SnapView supports 64-Kbyte chunk size only.

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Technical Notes


SnapView – Simulation Mode. SnapView Simulation Mode was removed in SnapView Release 2.10.X. It is no longer required with the enhancements to remove the SnapView memory budget limit.

SnapView – Non-persistent sessions and SPs. SnapView sessions are per SP and not per storage system, so you should not start a non- persistent session on a LUN that has failed over to the other SP, because that session will stop when the LUN trespasses back to the SP that owns the source LUN of the session.

Admsnap and SnapView – non-persistent session trespass. If, for any reason, the snapshot LUN is trespassed, the SnapView sessions for that LUN will terminate. This is normal because SnapView is not resilient to non-persistent LUN trespasses.

Admsnap - Command execution time. Admsnap uses the Fibre Channel bus to send its commands to the storage system. Any device configuration issues or extremely heavy I/O to the attached storage system will adversely affect communications. If an admsnap command fails when you believe it should have succeeded, retry the command.

Admsnap Generic Notes

Admsnap Support for Release 1, 1.1 and 1.2 versions of SnapView. Admsnap for Solaris, HP-UX, Linux, Windows 2000, and Windows Server 2003 do not support arrays running SnapView 1.2 or earlier.

Admsnap Platform-Specific Notes (Alphabetically by Platform)

AIX

SnapView persistent session on AIX with PowerPath®software. Admsnap commands issued to a LUN (activate, deactivate) while it is running a persistent SnapView session may appear to hang in the presence of a host-to-array-path failure. The admsnap command is not actually hung, but is experiencing timeouts at the driver level. The command will complete in a time frame dependent upon the number of configured host-to-array paths, number of LUNs and I/O load. To avoid this problem, repair any path faults and restore LUNs before issuing admsnap commands. If this is not feasible, try reducing I/O load, and wait until PowerPath failover is complete (all affected LUNs have trespassed), before issuing admsnap commands. [77912]

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Technical Notes


SnapView clones on AIX with ATF. To regain access to an online SnapView clone source LUN that had been previously marked offline from an AIX host running ATF, either reboot the host or perform an rmdev -d -l hdiskx followed by the cfgmgr command. [77638]

Admsnap with AIX. If you issue an admsnap command to a LUN on an AIX host and the LUN is currently not configured to use SnapView, I/O to that LUN may hang. You must reboot the host to regain access to the LUN. To avoid this issue, create a snapshot device for any LUN you intend to use with SnapView prior to issuing admsnap commands to that LUN.

Admsnap installation images for AIX. The admsnap CD now contains two directories for the AIX admsnap packages. The admsnap software for AIX 4.3.3 systems is located in the directory aix4.3 and the software for AIX 5.1 and 5.2 systems is located in the directory aix5.x.

Admsnap support for logical volumes. Admsnap has been enhanced in this release to recognize logical volumes.for the start and stop operations.

Admsnap. Admsnap now delivers an online man page.

DMP (Multiple Platforms)

Admsnap with DMP software. If you install and use the DMP software for Solaris, you must use persistent SnapView sessions. DMP-installed systems will sometimes generate I/O requests to both SPs for a LUN. For SnapView, this will cause a session to trespass when the non-owning SP receives the I/O request. A persistent session will survive the trespass operation and I/O will continue normally. Non-persistent sessions will terminate. Also, for admsnap operations that use the -o <pathname> parameter, you can also use the /dev/vx/rdmp/cXtXdXsX pathnames as arguments.

HP-UX

Admsnap support for HP-UX PowerPath. Version 02.03.004 of HP-UX admsnap supports HP-UX PowerPath Revision 4.x.

Admsnap support for HP-UX PowerPath. Version 2.1 of HP-UX admsnap supports HP-UX PowerPath with PowerPath patch 3.0.2.

Admsnap activate timings. When the -o option is not present on the admsnap activate command line, admsnap by default rescans the SCSI bus for new devices before activating the snapshot LUN. On IA64 systems (HP-UX 11.23), the rescan operation may take several minutes to complete. This delay can be avoided by adding the -r 0

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Technical Notes


option to the command line if the snapshot LUNs are already accessible by the host (that is, this is not the initial time the devices are being discovered by the host software). If the –o option is specified on the command line, then by default the SCSI bus is not rescanned, so the -r 0 option is not necessary.

Admsnap with HP-UX - Importing and exporting snap volumes on two hosts with different operating system revisions. The following procedure describes how to import and export snap volumes on two different revisions of HP-UX. [71822]

On the production host, do the following:

1. Unmount the file system from the volume group, using the following command:

umount filesystem-name 2. Deactivate and export the volume group, by issuing the

following commands:

vgchange -a n volume-name vgexport volume-name

Use the admsnap start command to start a session on the snapshot LUN. admsnap start -s session-name -o /dev/rdsk/cNtNdN where cN specifies the HBA number; tN specifies the SP number, and dN specifies the LUN number; for example c0t1d12.

3. On the backup host, use the admsnap activate command to activate the snapshot and obtain the snapshot device name in the form /dev/rdsk/cNtNdN.

admsnap activate -s session-name 4. Create a new volume group directory, using the following

form:

mkdir /dev/volume-name mknod /dev/volume-name/group c 64 0x0X0000

5. Issue the vgimport command, using the following form:

vgimport volume-name /dev/dsk/cNtNdN 6. Activate the newly imported volume group, as follows:

vgchange -a y volume-name 7. Once the snapshot is activated, mount the volume group to a

file system, using the following format:

mount /dev/volume-name/lvol1 /filesystem

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Technical Notes


Admsnap. The admsnap start command now recognizes a simple Veritas volume as a valid object type and will issue the start operation to all devices that comprise that volume.

Admsnap support for Logical Volumes. Admsnap has been enhanced in this release to recognize logical volumes.for the start and stop operations.

Admsnap. Admsnap now delivers an on-line man page.

Irix

Admsnap and SnapView with IRIX – xlv logical volumes. SnapView does not support the use of xlv logical volumes. As a result, you cannot use failover and SnapView in the same configuration. Failure to observe this restriction may result in a system panic, if an attempt is made to fail over a LUN while it is part of a SnapView session.

Linux

Admsnap. Admsnap no longer supports Linux 2.2 kernels Admsnap with Linux - Activate function. Currently the Linux host

cannot dynamically rescan the bus for new devices. Therefore the admsnap activate command on Linux cannot perform this function. Instead, you must reboot the Linux system. Before doing this, stop all I/O. After rebooting, run the admsnap activate command to list snapshot LUN device names.

Admsnap. The admsnap start command now recognizes simple Veritas volumes as a valid object type and will issue the start operation to all devices that comprise that volume.

Admsnap. The admsnap package now delivers an on-line man page. SnapView. The reboot of the Linux host may be slow if there are

deactivated snapshots in the hosts storage group. Activating the snapshots or removing them from the storage group will allow the reboot to complete normally.

NetWare

Admsnap with NetWare - Uninstalling Admsnap. You must manually uninstall the admsnap components by deleting the corresponding files and subdirectories from the emc\admsnap subdirectory, since the remove_admsnap.bat file was not included in the NetWare admsnap package. [76312]

Admsnap and SnapView with NetWare - Mounting snapshot LUNs on volumes. The command list devices or Scan All LUNs is required on the backup host before you mount snapshot LUN

20

Technical Notes


volumes. To make volumes available, you must issue a list devices or Scan All LUNs command from the server console.

SnapView with ATF on NetWare. Restoring sessions to the default SP for a Novell NetWare host running ATF via the atf_restore command may hang the NetWare console. A workaround is to use Navisphere CLI from the host to trespass the persistent SnapView sessions to their default storage processor as follows: navicli -h <IP addr> trespass LUN #. Then issue the atf_restore command. [78906]

SnapView with NetWare - NSS file system. EMC recommends not using the NSS file system when using SnapView software on a CLARiiON storage system.

SnapView with NetWare - Upgrading software. Before upgrading storage-system software via NDU, stop all SnapView sessions on that storage system. Failure to stop SnapView sessions on a NetWare platform can result in a host that is accessing the snapshot LUNs to panic (or ABEND). Since SnapView sessions are not persistent during SP shutdown, all the sessions will be stopped by the very nature of the NDU operation, which systematically issues a shutdown and reboot of the array SPs. This behavior does not adversely impact hosts that are accessing the source LUNs that have associated SnapView sessions. [70142]

Solaris

Admsnap with Solaris - Veritas volumes. As of admsnap 1.50, Solaris supports sessions on file systems mounted on top of Veritas volumes; for example,

admsnap start -s s1 -o /target

where /target is the mount point for a file system created on top of a Veritas volume.

admsnap start -s mysession -o /dev/rdsk/c2t0d0s3 admsnap start -s mysession -o /dev/rdsk/c2t0d1s1 admsnap start -s mysession -o /dev/rdsk/c2t0d5s7

For Solaris, admsnap 1.50 supports starting a session on simple Veritas volumes by specifying the volume name. For example, with vol01 in the example above, you can snap the whole volume by specifying admsnap start -s mysession -o vol01.

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Technical Notes


The operations that are not supported in the admsnap 1.50 release for Solaris, but may be added in a future release, are as follows:

• Starting a session on Veritas plexes. • Starting a session on Veritas subdisks. • Starting a session on Veritas sub-volumes. • Starting a session on ANY other Veritas virtual object.

Admsnap supports PowerPath PowerVolumes Admsnap will recognize PowerPath PowerVolumes as a valid object type for the start command. and will issue the start operation to all devices that comprise that volume.

SnapView supports PowerPath PowerVolumes for “same host access” PowerPath PowerVolumes allow the SnapCopy and Clone of a PowerPath PowerVolume to be accessed on the same host as the source copy. This feature is enabled by the PowerVolume software.

Admsnap. Admsnap now delivers an on-line man page.

Windows (NT, 2000, Server 2003)

Admsnap software media: The admsnap software for Windows Server 2003 is located in the folder named win2003.

Admsnap for Windows NT and “physicaldrive0”. Admsnap will not activate a SnapView session that has been assigned physicaldrive0 by the Windows NT host software. Typically, the C: drive is assigned the physicaldrive0 device. Admsnap is designed to not allow operations on the C: volume and physicaldrive0.

Admsnap and Nested Mount Points. Admsnap does not support nested mount points. The physical device name can be used as arguments to start and stop operations.

Admsnap and synchronizing clones. Admsnap clone_activate may cause a drive letter to be displayed in Explorer even if the clone is synchronizing. If this happens, execute admsnap clone_deactivate and then admsnap clone_activate once the clone is synchronized and fractured.

Admsnap with Windows Server 2003. A backup host reboot is required to properly dismount the stale Disk Volume mount point if the session is stopped without deactivating its snapshot first using admsnap.

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Technical Notes


SnapView clones and Microsoft Cluster Server (MSCS). Whenever you need to stop I/O to a clone or clone source, you must take the LUN offline in order to ensure MSCS stops generating I/O. This action is in addition to other actions such as admsnap clone_deactivate. The LUNs involved can be taken offline as follows.

• Locate the Microsoft Cluster Server Disk Group resource that includes the affected LUNs.

• Use the the Microsoft Cluster Administrator to take the Disk Group offline by right-clicking on the Disk Group and selecting Take Offline.

• Perform the clone operation.

When ready to resume I/O to the disk, use the Microsoft Cluster Administrator to bring the Disk Group(s) back online by right-clicking the Disk Group and selecting Bring Online.

SnapView and Clones. Following is an example of the proper sequence of steps for using admsnap with SnapView clones. 1. Create a Clone Group with the source and clone LUNs of equal

size. For this example, the drive letter assigned to the source LUN on the production host is H:.

2. On the production host, populate the clone source LUN with data and perform a complete synchronization.

3. After the synchronization is complete, fracture the clone.

4. On the backup host, execute admsnap clone_activate. A new device comes online and a drive letter is assigned. The data on the clone LUN is the same as the data on the source LUN. In this example, assume the drive letter assigned is F.

5. On the backup host, execute admsnap flush -o F.

6. On the backup host, execute admsnap clone_deactivate -o F. This will remove the volume from the Windows host.

7. On the production host, modify the content of the source LUN.

8. On the production host, execute admsnap flush -o H:

9. Synchronize the clone LUN. This operation will update the clone LUN with the changes made to the source LUN on the production host.

10. After the synchronization is complete, fracture the clone.

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Technical Notes


11. On the backup host, execute admsnap clone_activate. The modified data will be present on the volume. The admsnap clone_activate command may not return the same drive letter as the one from the previous step.

Admsnap clone activate with clone reverse synchronization. The indexing service should be disabled on the source LUN of the clone prior to performing a reverse synchronization.

Terminal Services. On Windows hosts, if Terminal Services is installed, admsnap operations may fail. To avoid these issues, do not use Terminal Services on the attached hosts.

Remote Desktop. On Windows hosts Remote Desktop may interfere with the drive-letter assignment operations of admsnap. The drive letter assignments may not be visible until the user logs off the host and logs back in.

Admsnap and drive letter restriction. Admsnap does not allow the use of drive letters A:, B:, C:, and D: with –o and –d options on admsnap activate or admsnap deactivate commands. If A, B, C or D drive letter is used, then only the physical drive will be activated and no drive letter will be assigned.

Admsnap deactivate and manual deletion of drive letters. On the backup host, if the drive letter is deleted before issuing the admsnap deactivate command, the Windows host will be unable to flush the file system buffers to the LUN on the storage system. This results in old data being presented to the user on subsequent SnapView session activates. To avoid this issue, do not delete the drive letters of the LUNs that you use for SnapView sessions.

Admsnap “list” on Windows platforms. Using admsnap list and specifying the WWN on a multi-partitioned LUN will list only one of the drive letters. Using the –d <drive letter> option on the command line will allow you to successfully list the other partition on the LUN.

Admsnap on multi-partitioned LUNs. When using admsnap and SnapView on multi-partitioned LUNs the user must properly select the session to be activated on the second host. For example, if the user starts two distinct sessions on the two partitions of a multi-partioned LUN, a single activate will allow the user to access both snapshot LUNs since SnapView operates at the LUN level – but the two snapshot LUNs will be from one session, not two.

Admsnap with Windows NT - Activate function. You can make Windows NT and Windows 2000 discover the new device dynamically (without rebooting) using the admsnap activate command. To make sure Windows rescans the device bus, add the following value to the Registry using regedt32:

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Technical Notes


Name: LunRescan Type: REG_MULTI_SZ Value: <you can leave this null> Added to key: \\HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Disk

Admsnap with Windows NT Version 4.0 - Activate and deactivate functions. If all the paths to one of the SPs have been disconnected by cable pull, admsnap activate will cause a Windows NT version 4.0 server, running an Emulex HBA driver version 2.11a2 or earlier, to panic when attempting to re-activate an activated or deactivated snapshot. This panic occurs only if ATF is installed on the NT server, and can be avoided by reconnecting the cables or by running Disk Administrator prior to activating the snapshot. Another abnormal behavior when attempting to activate a snapshot LUN with disconnected paths is that the snapshot LUNs originally owned by the disconnected SP will be trespassed, and thus, will stop all sessions belonging to those trespassed LUNs. [75279]

Admsnap Activate with Windows 2000 and Windows Server 2003. Admsnap activate will not allow the use of drive letters A:, B:, C:, or D: for command line arguments specified with the –d option. These drive letters are the default for the system devices and admsnap activate is designed not to allow the use of these volume letters. If the user specifies one of these drive letters for an activate command, admsnap will activate the session and report the physical drive the LUN is present on, but will not assign a drive letter (since the user requested A:, B:, C:, or D: and that drive letter cannot be assigned).

Admsnap Deactivate: Admsnap deactivate will not delete the drive letter if the volume is in use by services or applications on the host. For example, if Windows Explorer is open and the drive letter/volume which is to be deleted is being accessed, admsnap will not delete the drive letter and inform the user that an application is using the drive letter. • Dynamic Disks. When you use Windows 2000 Disk

Management to import dynamic disks that are displayed as foreign disks, you may receive the following error message: Internal error - disk group exists and is imported. After you accept the error message, the dynamic disks that you are importing are still displayed as foreign disks.

This behavior can occur if you are trying to import foreign disks that use the same disk group name as that of the current computer's disk group.

For additional information about disk groups, refer to Article 260113 in the Microsoft Knowledge Base.

25

Technical Notes


Output and Return Codes. The following changes have been made to the Windows 2000 and Windows Server 2003 admsnap. These changes affect the text output and return codes (exit codes) of the command.

• The output of the flush command has been changed to match the output of the 2.0 and earlier releases:

Prompt> admsnap flush -o f:

Flushed F:

• An error is now returned for an activate operation when no drive letter is assigned.

Prompt> admsnap activate -s lun_17_session

Scanning for new devices.

Activated session lun_17_session on device \\.\PhysicalDrive5.

Warning: No drive letter was assigned to any of the activated devices.

Prompt> echo %errorlevel%

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• An error is now returned for an activate operation when no drive letter is assigned for a multi-LUN activation where a drive letter could not be assigned to one of the devices. (In this example \\.\PhysicalDrive5 cannot be assigned a drive letter.)

Prompt> admsnap activate -s test


Activated session test on device \\.\PhysicalDrive3.


Warning: One or more devices failed to have a drive letter assigned.


11

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Technical Notes


• An error is now returned for an activate operation when no drive letter is assigned for a multi-LUN activate where a drive letter could not be assigned to one of the devices and the specified drive letter could not be assigned either. For all -d success output, the drive letter will be printed instead of the physical drive name if one exists.

Prompt> admsnap activate -s test -d e:


User specified drive letter e:

Activated session test on device G:.


Warning: The specified drive letter was not assigned to any activated devices.


11

• Option parsing failures now return an error.

Prompt> admsnap

Error: Operation not specified.

You must supply an operation.

Valid operations include: start, stop, flush, activate, deactivate, clone_activate, clone_deactivate, list, and help


22

27

Technical Notes


• An error is now returned when the drive letter specified could not be assigned and the drive letter specified on the command line is currently mapped to a network drive. In this case, the next available drive letter is not assigned or attempted to be assigned.

Prompt> admsnap activate -s lun_2_session -d y:


User specified drive letter y:

Activated session lun_2_session on device \\.\PhysicalDrive3.



11

• An error is now returned when the drive letter specified on the command line is already assigned and the next available drive letter is successfully assigned.

Prompt> admsnap activate -s lun_2_session -d e:


User specified drive letter e:

Activated session lun_2_session on device G:.



11

• An error is generated if the list option is specified and the -l and -d arguments do not match (the volume does not have the WWN specified).

Prompt> admsnap list -l 60:06:01:72:31:0C:00:00:1C:33:0E:E7:81:9E:D7:11 -d h:

The specified LUN WWN does not match any devices in object list.


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Technical Notes


• The admsnap command will return an error if the list option is specified and there are no CLARiiON® or Symmetrix® LUNs that match the default output (this can occur if there are LUNs in the storage group but the devices do not have drive letters assigned – the default output mode includes drive letters).

Prompt> admsnap list

Warning: There were no devices found whose LUN WWN could be listed in the default output format.


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• The admsnap command will return an error if the list option is specified and there are no CLARiiON or Symmetrix LUNs in the storage group.

Prompt> admsnap list

There were no devices found whose LUN WWN could be listed.


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Before installing the CLARiiON VSS Provider on a domain controller, the administrator of the Windows Server 2003 system must add the domain Administrators group to the roles folder under Administrators Tools > Component Services. Otherwise, the installation of the CLARiiON VSS Provider will fail because local accounts are disabled and only domain accounts exist on a domain controller.

Depending upon the configuration of the servers and CLARiiON arrays, up to five SnapView snapshot source LUNs or eight SnapView clone source LUNs can be used in a single ShadowCopy operation. Configurations beyond these limits may fail due to the VSS ShadowCopy Service requirement of completing the operation in a specified time limit of 30 seconds.

Creation of Plex (SnapView clone) Shadow Copies may fail if NetBIOS over TCP/IP has been enabled on the Windows Server 2003. .

• Disable NetBIOS over TCP/IP from the WINS tab of the Advanced TCP/IP Settings dialog box, which can be found under the Local Area Connection Properties.

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Documentation


• If NetBIOS over TCP/IP is required to be enabled, add map entries for the addresses of all connected array Storage Processors to valid hostnames in %SystemRoot%\system32\drivers\HOSTS.

Documentation

The following documents apply to this product release and are located on the SnapView documentation CD (P/N 068090623).

Part Number Publication

069001180 EMC SnapView 2.X for EMC Navisphere 6.X Administrator's Guide

069001181 EMC SnapView Command Line Interfaces Reference

069001193 EMC SnapView Version 2.x Installation Guide

Documentation Updates

This section describes changes to the SnapView online help, the EMC SnapView Version 2.X for Navisphere 6.X Administrator’s Guide (P/N 069001180), the EMC SnapView Version 2.X Installation Guide, and the EMC SnapView Version 2.X Command Line Interfaces Reference (P/N 069001181).

Installing the SnapView UI Add the following information to the SnapView Installation Guide: The SnapView UI is installed on all CX300, CX500, and CX700 storage systems at the factory.

30

Documentation Updates


SnapView Limits

In the SnapView Administrator’s and Reference Guides, replace the SnapView Configuration Guidelines table on page 1-11 with the table below:

Parameter CX700, CX600, or FC4700 CX500 or CX400 CX300 Clones Per Storage System Per Source LUN

100 maximum (includes source LUN and Primary or Secondary MirrorView™ images) 8 maximum



Clone Groups Per Storage System

50 maximum

25 maximum

25 maximum

Clone Private LUNs Per Storage System

2 required

2 required

2 required

Snapshotsa Per Storage System Per Source LUN




SnapView Sessionsa Per Source LUN

8 maximum

8 maximum

8 maximum

Reserved Pool LUNs Per Storage System

100 maximum

50 maximum

25 maximum

a. The limits for snapshots and sessions include SnapView snapshots or SnapView sessions and any reserved snapshots or reserved sessions used in another application such as SAN Copy.

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Software Media


SnapView and Admsnap Version Numbers

The version numbering scheme for the SnapView and admsnap software has changed to include leading zeros. For example, version 2.3 is now referred to as version 02.03.xxx. The SnapView documentation and online help do not reflect this change.

All references to SnapView (or admsnap) Version 2.3 (or higher) in the documentation should be replaced with SnapView (or admsnap) Version 02.03.xxx (or higher).

Important: Older 2.X versions of SnapView and admsnap are Versions 2.0, 2.1, and 2.2. These versions are lower than Version 02.03.xxx.

Software Media

The following table lists the applicable software media for this product release:

Product CD Part Number Description

SnapView 068090519 SnapView version 02.03.004 CD-ROM

Admsnap 068090628 Admsnap version 02.03.004 CD-ROM for the following platforms:

• AIX (4.3.3 and 5.x)

• HP-UX

• IRIX

• Linux 2.4

• NetWare

• Solaris

• Windows 2000

• Windows NT

• Windows Server 2003

Special Installation Instructions

NDU will require all SnapView sessions to be stopped prior to installation. If the sessions are not stopped before the NDU is attempted, the NDU will fail. This is required due to changes to the snapshot cache LUNs, which eliminate the upper limit of the memory budget. The NDU process will perform all of the necessary steps to complete the conversion of the cache LUNs during the installation.

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Troubleshooting and Getting Help


Troubleshooting and Getting Help

This section provides specific instructions for contacting EMC Customer Support and obtaining additional information about EMC products.

Where to Get Help

For questions about technical support and service, contact your service provider.

If you have a valid EMC service contract, contact EMC Customer Service at:

United States: (800) 782-4362 (SVC-4EMC)

Canada: (800) 543-4782 (543-4SVC)

Worldwide: (508) 497-7901

Follow the voice menu prompts to open a service call, then select CLARiiON Product Support.

Sales and Customer Service Contacts

For the list of EMC sales locations, please access the EMC home page at:

http://www.emc.com/contact/

For additional information on the EMC products and services available to customers and partners, refer to the EMC Powerlink™ website at:

http://powerlink.emc.com

For CLARiiON documentation, after you log in to Powerlink, select Support > Document Library.

Copyright © 2004 EMC Corporation. All Rights Reserved.

EMC believes the information in this publication is accurate as of its publication date. However, the information is subject to change without notice.

THE INFORMATION IN THIS PUBLICATION IS PROVIDED "AS IS." EMC CORPORATION MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WITH RESPECT TO THE INFORMATION IN THIS PUBLICATION, AND SPECIFICALLY DISCLAIMS IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

EMC2, EMC, CLARiiON, Navisphere, and PowerPath are registered trademarks and Access Logix, FLARE, Powerlink, SAN Copy, SnapView, and MirrorView are trademarks of EMC Corporation. All other trademarks mentioned herein are the property of their respective owners.

http://www.emc.com/contact/

http://powerlink.emc.com/

Adm Snap

Documents

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