EMC DL1500 and DL3000 with Veritas NetBackup OpenStorage (OST) · Configure the backup policy ......

EMC DL1500 and DL3000 with Veritas NetBackup OpenStorage (OST)

Best Practices Planning

Abstract

This white paper provides specific configuration and best practices information for using EMC® Disk Library 1500 and 3000 with the Veritas NetBackup OpenStorage (OST) disk option.

October 2009

Copyright © 2009 EMC Corporation. All rights reserved.

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Part Number h6473.2

EMC DL1500 and DL3000 with Veritas NetBackup OpenStorage (OST) Best Practices Planning 2

Table of Contents Executive summary ............................................................................................4 Introduction.........................................................................................................4

Audience ...................................................................................................................................... 4 Terminology ................................................................................................................................. 4

OpenStorage overview .......................................................................................5 Key features................................................................................................................................. 5 OST configuration planning ......................................................................................................... 6 Additional settings and considerations ........................................................................................ 7

Network connectivity..........................................................................................8 Configuring the OST environment ..................................................................10

OST requirements...................................................................................................................... 10 DL setup..................................................................................................................................... 10

Configure a Windows domain or join a workgroup (when using the Windows client plug-in only)........................................................................................................................................ 11 Configure the storage server.................................................................................................. 12 Create a logical storage unit (LSU) ........................................................................................ 13

NetBackup setup........................................................................................................................ 13 Register the storage server and discover the LSU ................................................................ 14 Configure a disk pool.............................................................................................................. 15 Configure a storage unit ......................................................................................................... 17 Confirm the OpenStorage configuration................................................................................. 18 Spanning disk volumes .......................................................................................................... 19 Configure the backup policy ................................................................................................... 19

Recovery of images ..........................................................................................20 NetBackup optimized duplication ...................................................................21

General considerations for optimized duplication and the DL ................................................... 23 Seeding (pre-populating the target system) ........................................................................... 23 Performance considerations................................................................................................... 24 Effects of distance and latency............................................................................................... 24 Sizing considerations ............................................................................................................. 25

Configuring NetBackup optimized duplication ........................................................................... 25 CLI (bpduplicate) .................................................................................................................... 26 Storage Lifecycle Policies ...................................................................................................... 26 Vault ....................................................................................................................................... 29

Disaster recovery ....................................................................................................................... 30 Conclusion ........................................................................................................30 References ........................................................................................................30


Executive summary The Veritas NetBackup OpenStorage (OST) disk option provides an API that allows NetBackup to use disk appliances, such as the DL, for backup storage without having to emulate virtual tape libraries (VTL). The DL OST feature introduced in DL version 1.1 is a licensed option of the EMC® DL1500 and DL3000. The DL OST option provides a software plug-in that is installed on NetBackup media servers. NetBackup media servers use the plug-in to communicate with the DL. NetBackup, when used with an OST-enabled DL, manages the DL storage as logical entities (disk pools) while the DL controls the deduplication and replication of that data. NetBackup maintains catalog consistency of all copies of the backup images. This solution substantially reduces the storage capacity required for backup data. Electronic replication of deduplicated data becomes an attractive solution for those organizations looking to store backup data at a secondary location in an economical and timely fashion.

Introduction This white paper describes how the OpenStorage (OST) option of the DL1500 and DL3000 integrates with the OpenStorage feature of Veritas NetBackup. It presents an overview of the OST feature, how to configure the DL, how to set up NetBackup for OST when using the DL as a storage target, how to restore images, and how to replicate data to another DL using NetBackup’s optimized duplication feature. It also presents recommended practices to achieve optimal results.

Audience This white paper is intended for EMC customers, system engineers, and members of the EMC and partners professional services community who are interested in configuration and best practices information for the DL product line’s OpenStorage (OST) option.

Terminology • Application program interface (API) – A set of functions provided by the OpenStorage feature of

NetBackup that allows integration of NetBackup with intelligent disk appliances via a plug-in supplied by the disk appliance vendor.

• Backup-to-disk (B2D) – A backup solution where data is written to hard disk instead of tape. • Balance-rr mode – A “round-robin” algorithm for transmitting and receiving data to and from peer

systems. This mode is also referred to as Mode 0 (see also Link Aggregation Control Protocol). • Client - Any system with data to be backed up. The client software is specific to the operating system

on which it is installed. Normally, a client operates under the control of the master server according to the policies and schedules set forth by the administrator.

• Deduplication – Process of detecting and identifying the redundant variable-length blocks (or data segments) within a given set of data to eliminate redundancy.

• Disk volume – In NetBackup, a logical unit of disk storage. • Immediate deduplication – Process of deduplicating the backup datastream as it is ingested by the

DL appliance (see also scheduled deduplication). • Link Aggregation Control Protocol (LACP) – Method for controlling the bundling of several

physical Ethernet ports together to form a single logical channel. LACP allows a network device to negotiate an automatic bundling of links by sending LACP packets to the peer (directly connected device that also implements LACP). This mode is also referred to as Mode 4 (see also balance-rr mode).

• Logical storage unit (LSU) – A logical unit of disk storage on the DL. • Master server - The manager of a storage domain. An administrator can control all NetBackup

functions in the storage domain from the master server. It manages all backups, archives, and restores, and is responsible for all catalog updates.


http://en.wikipedia.org/wiki/Computer_port_%28hardware%29

• Media server – A server hosting one or more backup devices. Media servers are directed by the

master server and provide additional storage by enabling NetBackup to use the storage devices they control.

• OpenStorage (OST) – A feature of NetBackup that enables media servers to communicate directly with disk devices.

• Optimized duplication – Replication of a deduplicated image stored on one DL to another DL. This duplication process is controlled, monitored, and cataloged by NetBackup.

• Plug-in – Vendor-specific code that functions as an interface between NetBackup’s OpenStorage API and the vendor’s disk storage system.

• Policy-based deduplication – The choice of immediate, scheduled, or no deduplication. • Remote replication – Backup data residing on a DL is copied over a LAN or WAN to another DL for

disaster recovery protection. • Scheduled deduplication – Deduplication of data occurs after the backup stream has been ingested by

the DL (see also immediate deduplication). • Storage server - An entity that writes data to and reads data from disk storage. A storage server has a

mount on the file system on the storage. The storage server is defined on the DL. • Virtual Tape Library (VTL) – Software emulation of a physical tape library system.

OpenStorage overview OpenStorage (OST) is a feature of Symantec’s Veritas NetBackup. OST integrates NetBackup with disk backup devices, such as the DL. OST enables NetBackup media servers to communicate with disk devices without employing tape emulation.

The OST option of the DL makes disk volumes called Logical Storage Units (LSUs) available to a media server. Multiple NetBackup media servers, each with the DL OST plug-in installed, can use the same LSU on a DL as a disk volume.

The NetBackup system sets policies that control when backups occur while the DL performs data deduplication and replication. Backups, replication, and restores are managed from a single NetBackup console and can use those DL features exposed to it through the client plug-in. NetBackup manages all images (collections of data) in the NetBackup catalog, even when the DL creates the images.

Key features An OST solution provides centralized management and storage capabilities such as:

• Shared disks. Multiple NetBackup media servers can access the same disk volume concurrently. • Load balancing and performance. NetBackup balances its backup jobs and storage usage by choosing

the least full disk volume and least used media server in the environment. • DL data deduplication and replication. Images backed up to the DL using OST are deduplicated and

can later replicate to another DL without requiring any user intervention. • NetBackup optimized duplication. NetBackup leverages the DL’s ability to replicate deduplicated

images to efficiently duplicate an image from one DL to another. • Since NetBackup is managing the duplication of LSU data, multiple targets can be configured through

the Storage Lifecycle Policies in NetBackup with NetBackup aware of all copies.

Replication of OST images does not require a DL replication license. However, improved replication performance of OST images can be achieved when a replication license is present and an OST image is configured for both DL replication and NetBackup optimized duplication.


OST configuration planning Figure 1 illustrates the components present in an OST environment and where they reside.

Figure 1. OST environment The OST components have the following functions: • OpenStorage API

The OpenStorage API is a set of commands that gives NetBackup the ability to communicate with the DL. The DL exposes its functionality through a client plug-in that provides an interface through which NetBackup is able to control the creation, duplication, and deletion of backup images while the DL performs those tasks.

• EMC OST plug-in The OST plug-in, provided by EMC, is an interface between the NetBackup API and the storage server defined on the DL.

• Storage server The storage server performs the tasks of writing data to and reading data from the DL logical storage units (LSUs). The storage server defined on the DL is also configured within NetBackup in the disk pool to manage the DL disk volume (LSU).

• Logical storage unit (LSU) The LSU is a unit of storage defined in the DL available for use as backup media. The LSU is a disk volume in the storage pool available to NetBackup.

• Disk pool The storage destination for a NetBackup storage unit. A disk pool specifies a disk volume (LSU) defined in the DL as well as the storage server to manage that LSU.


• Storage unit

A logical target for NetBackup operations of type “disk” and disk type “OpenStorage(EMC)” that specifies the media servers that can use a disk pool.

When a backup begins, NetBackup estimates the size of the backup and then selects a disk volume (LSU) to use in the disk pool specified by the backup policy. The disk volume used is based on available capacity in an LSU and the predicted size of the backup. NetBackup tries to write the backup data to a single disk volume.

There is a known limitation with NetBackup 6.5.3 and earlier where backup images cannot span disk volumes within a disk pool. If the size of the backup exceeds the available capacity in a disk volume, the backup fails and NetBackup reports a media error. With NetBackup 6.5.4 and later, disk volumes can be configured as described in “Spanning disk volumes” on page 19 to span to accommodate larger backups.

When configuring the DL with storage servers and LSUs, consider the types of backups to be performed to the DL using NetBackup OST. Create storage servers for the different types of data and LSUs sized to accommodate the largest backups. Create as many LSUs as needed to accommodate the backups performed during desired retention period.

For example, customer XYZ regularly backs up two different types of data:

• Oracle database data consisting of one 3.4 TB full backup performed each Saturday and daily incremental backups of 0.5 TB each per week on all other days. All backups are retained for four weeks.

• Filesystem data consisting of one 1.6 TB full backup and daily incremental backups of 0.8 TB each per week. Full backups are retained for 1 month and incremental backups are retained 2 weeks (12 days).

Here, two storage servers can be defined, one to manage to Oracle data and the other to manage the filesystem data. Multiple LSUs are defined for each data type.

For the Oracle data, one way of looking at the LSUs needed is to always have an LSU sized to each of the full backups. Additional LSUs can be created for the incremental backups, but sized to be equal to or less than that required for a full backup. For example, four LSUs of 3.5 TB can be created for the full backups. Since the incremental backups are only 0.5 TB, consider four additional LSUs of 3.5 TB. The first full backup consumes LSU-1. The next six incremental backups consume 3.0 TB of LSU-2. When the second full backup is performed, NetBackup uses LSU-3, and so on.

For the filesystem data, four LSUs are needed for the 1.6 TB full backups. Since the incremental backups are 0.8 TB in size and 12 are to be retained, consider creating six additional LSUs. Here a total of 10 1.75 TB LSUs can be used.

If additional disk pool storage is needed at a later time, new disk pools can be created and merged with the current pools.

Additional settings and considerations The following describes several NetBackup settings and best practices for optimizing the backup environment:

• Avoid running disk-intensive applications such as virus scanning on the backup client when it is backing up or restoring files.

• If the source data for the backup is located on a single, non-RAID physical disk and multiple streams are running in parallel, the source physical disk could become a performance bottleneck because of parallel reading. Therefore, only run a single backup stream on NetBackup clients when the data to be backed up is on a single physical disk.

The following describes several DL best practices for optimizing backup performance and deduplication ratios:


• The DL supports up to 100 storage servers simultaneously allowing concurrent backup jobs to occur to

their own disk volumes, resulting in faster, more reliable backups. • To achieve optimal deduplication, do not enable compression at the NetBackup client. Data that

changes frequently should be uncompressed when transmitted to the DL to increase the matches the deduplication engine can find in the datastream. Compressing frequently changing data prior to sending it to the DL will most likely result in negligible redundancy and poor deduplication ratios. The DL, in addition to deduplication, hardware-compresses the deduplicated data when writing to storage.

• The use of multiplexing adds additional header information to the data, significantly lowering the deduplication ratio that can be achieved. The DL can deduplicate an intermingled backup stream, but not at optimal rates. EMC recommends disabling multiplexing to optimize deduplication results.

• Encryption does not affect deduplication of files that do not change between backups. However, encryption will cause even a small change in a file to ripple throughout a file when it is encrypted, greatly reducing the commonality that can be found between current and prior versions, or similar but not identical documents on different machines. Changing the data zone encryption passphrase will also change the encrypted form of every document, preventing deduplication from finding commonality between current and prior versions. As a result, software client-side encryption prevents optimal deduplication from taking place since data that is already encrypted cannot be efficiently deduplicated once it reaches target storage. To achieve encryption of backup data, consider the use of an encryption appliance deployed between the DL and the physical tape library.

• The DL1500 and DL3000 are stand-alone backup-to-disk (B2D) appliances offering a network-attached storage (NAS) front end (IP) and an optional virtual tape library (VTL) front end (FC). These appliances can be configured to present an NFS share, CIFS share, storage server, or a VTL to the backup server. When enabled, NAS B2D, OST, and VTL functionality can be used simultaneously.

Network connectivity The DL contains six or eight Gigabit Ethernet ports for the DL1500 and DL3000, respectively, configured as a bonded network interface. All six or eight ports service replication traffic, appliance management traffic, and NAS and OST data traffic. Therefore careful planning and timing can optimize the performance of each particular operation. One way to achieve this is by scheduling them to be performed at particular times.

The bonding method used for the DL ports can be either the round-robin policy (Mode 0), which transmits packets sequentially across all ports for load balancing and fault tolerance, or LACP (Mode 4), which utilizes IEEE 802.3ad dynamic link aggregation.

Significant performance optimization will be achieved through configuration settings on managed Ethernet switches. For Mode 0 and Mode 4, EMC recommends using managed switches to group the physical port connections to which the DL appliance is connected.

For Mode 0, use a managed switch with the ports used by the DL configured for "trunking" or "EtherChannel" without LACP or pAgP to maximize performance potential. Refer to the vendor documentation for specific instructions when configuring the port group.

For example, to configure a Cisco 6500 Series switch for a common EtherChannel group, run the following command from the Cisco switch CLI:

set port channel mod/ports... [admin_group] mod = switch module ports = port numbers to be added to the port channel group. admin_group = name of port channel group (optional)

For example:

set port channel 2/1-8


For Mode 4, switches that utilize IEEE 802.3ad dynamic link aggregation allow their ports to be automatically grouped together to form an ultra-high-bandwidth connection that greatly expands bandwidth capacity to the network. This aggregation of DL port connections potentially improves NAS data ingest or replication performance depending on the environment.

For example, to configure a Cisco 6500 Series switch for an EtherChannel group with LACP, run the following commands from the Cisco switch CLI:

set channelprotocol lacp mod set port lacp-channel mod/ports mod = switch module ports = port numbers to be added to the port channel group

For example:

set channelprotocol lacp 2 set port lacp-channel 2/1-8

For more information on programming EtherChannel groups and the LACP mode when using Cisco 6500 Series switches, see:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/catos/8.x/configuration/guide/channel.html#wp1020899

For Mode 0, all DL ports connect to the same Ethernet switch. Splitting bonded ports on a DL between multiple switches, however, is supported on certain switches when using Mode 4. Consult the switch vendor’s documentation.

When using Mode 0, make sure LACP is disabled when configuring the EtherChannel port group on managed switches. When using Mode 4, only connect to Ethernet switches that support IEEE 802.3ad dynamic link aggregation and are properly configured for LACP.

In general:

• Use a dedicated network by configuring a separate network or use QoS features that guarantee network bandwidth.

• Alternatively, use virtual networks (VLANs) to segregate backup from production network traffic. • Set network interface cards (NICs) for servers and clients to full duplex. Set all routers to full duplex. • Use only CAT 5e or CAT 6 cables (1 Gb/s rated cables). • If using a DNS server, verify the DNS server configuration settings are correct. • When connecting multiple DL Ethernet ports to the network when using Mode 4 (LACP), make sure

the proper LACP settings on the switch are configured. Consult the switch vendor’s documentation for the configuration steps.

• For redundancy, connect at least two DL Ethernet ports to an Ethernet switch. Connecting all available DL Ethernet ports to a switch is recommended.

• Set each switch port used by the DL to auto-negotiate/auto-sensing. The DL network interface cards are preset to auto/auto and cannot be changed.

• When using Mode 0 (balance-rr mode), use a managed switch configured for "trunking" or "link aggregation" or "EtherChannel" to maximize performance potential. Refer to the vendor documentation for the switch for specific instructions when configuring the port groups. Do not use the LACP settings on the switch.

Keep the following in mind:

• Concurrent operations on the DL will have a significant impact on performance.




• The DL does not support jumbo frames. • Splitting bonded ports on a DL between multiple switches is not supported when using Mode 0. • Splitting bonded ports on a DL between multiple switches is supported on certain switches when using

Mode 4. Consult the switch vendor’s documentation.

Configuring the OST environment Setting up the OST environment requires the following configuration steps:

• Install the DL in the environment and make sure the OST license is installed. • Install the DL OST client plug-in on all media servers that connect to the DL. • Configure the DL with a storage server and a logical storage unit (LSU). • Configure NetBackup, adding the DL storage server and LSU to a disk pool. • Create a storage unit in NetBackup that references the disk pool. • Create a backup policy.

OST requirements DL version 1.1.3.3 and later support a client plug-in for Solaris, Linux, and Windows. Refer to the EMC Support Matrix on Powerlink® for the supported operating systems for OST.

No special installation is required for the NetBackup components of OpenStorage. Prerequisites are as follows:

• The NetBackup master server and all NetBackup media servers that use the feature must be at NetBackup 6.5.3 or later. Note: EMC recommends using NetBackup 6.5.4.

• You must activate the feature by installing NetBackup’s OpenStorage Disk Option license key on the NetBackup master server.

• The OST API client plug-in (available from EMC) is installed on all NetBackup media servers that connect to the DL. To obtain the plug-in, go to the EMC Powerlink website (http://powerlink.emc.com) and select Support > Software Downloads and Licensing > Downloads D > Disk Library.

• The DL OST license (available from EMC), which is installed on the DL.

DL setup Before you can configure OST in NetBackup, the DL must have storage servers and LSUs defined.

After physically installing the DL, connecting it to your network, and adding the OST license, set up the DL in your backup environment as follows:

• If using the Windows client plug-in, configure a Windows domain.

• Configure the DL with one or more storage servers each with one or more logical storage units (LSUs). Each LSU will be seen as a “disk volume” by NetBackup and contain the images written to the DL.

The maximum size of an LSU is 8 TB.


http://powerlink.emc.com/

Configure a Windows domain or join a workgroup (when using the Windows client plug-in only)

Since only one value for a workgroup or Active Directory domain can be entered, either workgroup or Active Directory domain validation will be used but not both at the same time. Also, only one workgroup name or Active Directory domain value can be used by all Windows systems using this DL system.

1. Join a workgroup or Active Directory domain as Administrator. (Use the same authentication type as the media server that will use the logical storage unit).

Figure 2. Configuring a Windows domain

2. Under Device Manager/Services in Windows, edit the following services: NetBackup Client Service, NetBackup Device Manager, and NetBackup Remote Manager and Monitor Service.

a. Open the Windows Services directory and stop all NetBackup services.

b. Select a NetBackup service.

c. Under the Log On tab select This account and enter the Administrator account credentials.

The Administrator account credentials need to match those configured for the DL.

d. Repeat steps b and c for the remaining NetBackup services.

e. When all necessary edits have been made, restart the NetBackup services and exit the Windows Services directory.


More detailed information about configuring these services is available at the following URL: http://seer.entsupport.symantec.com/docs/295201.htm

Configure the storage server Configure a storage server on the DL.

1. Click Configuration > Disk Backup > OST.

2. Select Storage Servers > Add.

Figure 3. Creating a storage server on the DL

3. Enter a Name for the storage server and the Max Connections (number of backup jobs that can be active at a time with the storage server).

EMC recommends using a value of 20 or less to avoid impacting backup performance.

4. Select the NFS protocol for the storage server if using Solaris or Linux; select the CIFS protocol if using Windows.

5. Create additional storage servers following steps 2-4 as desired.


http://seer.entsupport.symantec.com/docs/295201.htm

Create a logical storage unit (LSU) When the storage server is created, create one or more LSUs. The LSU is the disk volume to which backup images are written.

Figure 4. Creating an LSU

1. Click Configuration > Disk Backup > OST.

2. Select LSU > Add.

3. Select the storage server with which the LSU will be associated from the pull-down list.

4. Enter a name for the LSU.

5. Specify the physical capacity of the LSU in GB. The maximum size of an LSU is 8 TB. LSUs need to be sized to accommodate the largest backup written to the disk pool at a time. LSUs cannot be spanned with NetBackup 6.5.3 and earlier. NetBackup 6.5.4 and later support spanning of LSUs to accommodate larger backups.

The physical capacity specified is the desired size of the disk volume for fully hydrated backup images (the DL’s logical representation of the data size when it is undeduplicated and uncompressed). It does not represent the actual physical capacity consumed on the DL by the backup images.

6. Create additional LSUs by following steps 2-5. See the section “OST configuration planning” on page 6 for LSU recommendations.

NetBackup setup Make sure the OST plug-in from EMC has been installed on all media servers connected to the DL before beginning this procedure.

After the storage server and LSU have been configured on the DL, configure NetBackup as follows:

• Register the DL storage servers with NetBackup and discover the LSUs. • Configure disk pools and storage units in NetBackup.


• Configure the backup policy.

More detailed information about the NetBackup OpenStorage disk option can be found in the Veritas NetBackup Shared Storage Guide for UNIX, Windows, Linux, which is available at:


Register the storage server and discover the LSU

The format for “storageserver_name” in steps 1 and 2 below is “DL-storage-server_DL IP address of the DL” for Solaris, Linux, and Windows. An example is newost_192.168.15.196.

1. Register the DL storage server with NetBackup as follows:

For a Solaris or Linux host: /usr/openv/NetBackup/bin/admincmd/nbdevconfig –creatests –storage_server storageserver_name –stype EMC –media_server media_servername –st 9 For a Windows host: c:\Program Files\Veritas\NetBackup\bin\admincmd\nbdevconfig –creatests –storage_server storageserver_name –stype EMC –media_server media_servername –st 9 For example: c:\Program Files\Veritas\NetBackup\bin\admincmd\nbdevconfig –creatests –storage_server newost_192.168.15.196 –stype EMC –media_server gonzo –st 9

2. Add the credentials for the storage server so that the media server can log in to it:

For a Solaris or Linux host: /usr/openv/volmgr/bin/tpconfig –add –storage_server storageserver_name –stype EMC –sts_user_id ndmpuser –password password For a Windows host:

For a Windows host, the –sts_user_id and –password options must specify the Administrator or any user who has the right to join the domain. By default, this is any user in the Administrator or Domain Admin group. These options must also match the user credentials specified for the workgroup or Active Directory for the DL.

If the credentials belong to a Workgroup user:

C:\Program Files\Veritas\volmgr\bin\tpconfig –add –storage_server storageserver_name –stype EMC –sts_user_id username –password username_password If the credentials belong to an Active Directory user:

C:\Program Files\Veritas\volmgr\bin\tpconfig –add –storage_server storageserver_name –stype EMC –sts_user_id domainname\username –password username_password For example: C:\Program Files\Veritas\volmgr\bin\tpconfig –add –storage_server newost_192.168.15.196 –stype EMC –sts_user_id Administrator –password admin_password



Configure a disk pool NetBackup uses disk pools to make the LSU created on the DL available for use as backup media.

1. In the NetBackup Administration Console, select Media and Device Management > Devices > Disk Pools.

2. Right-click on the right side of the screen and choose New Disk Pool.

Figure 5. Creating a new disk pool

3. Select OpenStorage (EMC) for the disk pool type.

Figure 6. Select OpenStorage (EMC) as the disk pool type


4. Select the Storage Server configured on the DL. The example in Figure 7 is newost_192.168.15.196.

Figure 7. Select the DL storage server

5. Select the LSUs to be included in the disk pool.

Figure 8. Add the LSU to the disk pool EMC DL1500 and DL3000 with Veritas NetBackup OpenStorage (OST) Best Practices Planning 16

6. Enter a name for the disk pool and complete creation of the disk pool.

Figure 9. Confirm the disk pool parameters

The format for “storageserver_name” is “DL-storage-server_DL IP address of the DL” for Solaris, Linux, and Windows. An example is newost_192.168.15.196.

Configure a storage unit Create a storage unit to use the disk pool just configured.

1. Configure a new storage unit.

Figure 10. Configure a storage unit for the disk pool


a. Enter a unique name for the storage unit.

b. Select whether all media servers with access credentials to the storage server can use the disk pool or just specific ones.

c. Specify the maximum number of jobs that NetBackup can send to the storage unit at a time. In general, this value corresponds to the Max Connections value set for the DL storage server.

d. Specify the largest fragment size that NetBackup can create when backing up to disk.

When multiple media servers share a disk volume, the fragment size parameter in a storage unit can limit the amount of data a media server can write to a disk volume at a time.

Confirm the OpenStorage configuration Run the following commands on each NetBackup media server to be used to back up data to the DL in the OST environment. The first command shows the disk storage unit configuration. The second command displays the disk storage units to which the media server has access credentials.

For a Solaris or Linux host:

/usr/openv/netbackup/bin/admincmd/nbdevquery –liststs

For a Windows host:

c:\Program Files\Veritas\NetBackup\bin\admincmd\nbdevquery -liststs

The output will be similar to the following:

V6.5 ost_192.168.15.196 EMC 9 V6.5 newost_192.168.15.196 EMC 9

For a Solaris or Linux host:

/usr/openv/volmgr/bin/tpconfig –dsh

For a Windows host:

C:\Program Files\Veritas\volmgr\bin\tpconfig –dsh

The output will be similar to the following:

Media Server lzb2d1 Storage Server ost_192.168.15.196 User id: Administrator Storage Server Type: NearStore Storage Server Type: SnapVault Storage Server Type: EMC

Media Server lzb2d1 Storage Server newost_192.168.15.196 User id: Administrator Storage Server Type: NearStore Storage Server Type: SnapVault Storage Server Type: EMC


Spanning disk volumes

This feature requires NetBackup 6.5.4 or later.

Backups exceeding the maximum size of your disk volumes (or 8 TB) require multiple disk volumes. To ensure that as many disk volumes are used as needed, the SpanImages attribute needs to be set for those storage servers first and disk pools second to which these backups are written or restored.

1. Set the spanning attribute on the storage server.

For a Solaris or Linux host: /usr/openv/NetBackup/bin/admincmd/nbdevconfig –changests –storage_server storageserver_name –stype EMC –setattribute SpanImages For a Windows host: c:\Program Files\Veritas\NetBackup\bin\admincmd\nbdevconfig –changests –storage_server storageserver_name –stype EMC –setattribute SpanImages For example: c:\Program Files\Veritas\NetBackup\bin\admincmd\nbdevconfig –changests –storage_server newost_192.168.15.196 –stype EMC –setattribute SpanImages

2. Set the spanning attribute on the disk pool(s):

For a Solaris or Linux host: /usr/openv/NetBackup/bin/admincmd/nbdevconfig –changedp diskpool_name –stype EMC –setattribute SpanImages For a Windows host: c:\Program Files\Veritas\NetBackup\bin\admincmd\nbdevconfig –changedp diskpool_name –stype EMC –setattribute SpanImages For example: c:\Program Files\Veritas\NetBackup\bin\admincmd\nbdevconfig –changedp newdiskpool –stype EMC –setattribute SpanImages

Configure the backup policy Configure a backup policy for backups to the OpenStorage storage unit using normal NetBackup processes.

Symantec recommends that you do not send catalog backups to an OpenStorage disk pool because of the complexity of disaster recovery.


Figure 11. Create a backup policy

EMC recommends not selecting the Compression and Allow multiple data streams options when creating the backup policy to ensure optimal deduplication ratios can be attained.

Recovery of images Use normal NetBackup processes to restore data from LSUs on the DL.


NetBackup optimized duplication Optimized duplication (Figure 12), also referred to as OST replication or optimized copy, is another duplication option of NetBackup. Using a NetBackup duplicate method, the DL replicates a deduplicated backup image from one DL disk pool to another DL disk pool. The DL sends only the unique data in images specified by NetBackup that is not present at the target DL, offloading the NetBackup media servers and reducing bandwidth utilization. Although the DL’s replication mechanism is used to perform the copy, NetBackup is fully aware of the image copy created on the target DL.

To perform optimized duplication with the DL, the source and destination disk pools must be DL disk pools. The media server that initiates optimized duplication must connect to and have access credentials to both the source and target DLs to confirm the copy of the image occurred and maintain records of the image copies and their locations in the NetBackup catalog. Figure 12 illustrates an optimized duplication configuration.

Figure 12. Optimized duplication A DL replication license is not required for duplication of OST images. NetBackup optimized duplication uses the DL replication mechanism to perform the duplication. The NetBackup duplicate method will trigger the replication function in the DL through the OST plug-in if both the source and destination volume are OST disk volumes. In this configuration, NetBackup manages the data transfer. The DL does not replicate any data associated with that image until this trigger occurs.


With NetBackup managing data duplication, replication of an OST image can take place to one or more target DLs. Each copy of the source image is performed sequentially. That is, copy 1 completes before copy 2 starts.

NetBackup optimized duplication can also be enhanced when a DL replication license is installed and enabled on the DL storage server containing disk volumes to be duplicated. In this configuration, a significant performance advantage can be achieved as shown in Figure 13.

Figure 13. NetBackup optimized duplication performance Major advantages of using NetBackup optimized duplication with a DL replication license include:

• Unique data written to a disk volume (LSU) continuously transfers to target DL as it deduplicates instead of waiting until the duplicate trigger occurs. Since most or all of the data associated with the image to be duplicated is present at the target when NetBackup issues the duplicate trigger, the copy is available much sooner.

• If all the deduplicated data associated with the image to copy is already at the target DL when the duplicate trigger occurs, only the metadata description associated with that image needs to replicate at that time.

• AES-128 encryption can be optionally enabled for storage servers configured for DL replication

Some disadvantages of this configuration are:

• Replication of VTL, NAS, and/or OST data can occur only to the same target DL system. • Optimized duplication performance gains are not realized if DL replication of a storage server is

configured for a target DL system that is different from the OST optimized duplication target system


for that storage server. In this case, NetBackup would be unaware of the OST images replicated to the DL replication target system.

• It requires both the NetBackup optimized duplication setup as well as DL replication configuration of a storage server. Individual LSUs are not configurable for replication.

Note: When using NetBackup optimized duplication with DL replication, the replication configuration involves enabling replication only on the storage server. No namespace schedule (Replicate Daily at …) or Sync ID is specified. The NetBackup duplicate trigger will ensure that the metadata description of the OST image copies to the target disk volume.

General considerations for optimized duplication and the DL When using NetBackup optimized duplication to copy images to another DL system, keep the following in mind:

• Always assess the network between the source and target DL systems in both directions. This will ensure that sufficient bandwidth is available to support the maximum amount of data to be replicated within the replication window. This can be done by performing a formal assessment if necessary.

• Seeding of the target system, as described in the next section, is almost always required. • Do not place the source and target DL systems into production until required optimized duplication

windows are met. When optimized duplication falls behind (exceeds the copy window), it is hard to catch up.

• If an optimized duplication job fails, NetBackup 6.5.3 and earlier will duplicate the source image using its normal duplication method. Since this operation duplicates the native source image using the media server, the copy will take considerably longer possibly impacting the copy window as well as the efficiency of other DL and NetBackup operations.

• In NetBackup 6.5.4 and later, duplication of the source image is not retried if the optimized duplication job fails. To configure NetBackup to duplicate the source image using its normal duplication if an optimized job fails, add the following entry to the bp.conf file on the NetBackup master server: RESUME_ORIG_DUP_ON_OPT_DUP_FAIL = TRUE

Note: An optimized duplication job initiated by a storage lifecycle policy that fails causes the storage lifecycle policy to retry that operation as an optimized duplication job only.

Seeding (pre-populating the target system) The initial optimized duplication operations are time-consuming and will usually take significantly more time than later copies because the data is typically new and unknown to the target DL.

For optimized duplication, the goal is to facilitate the transfer of the large amount of unique data produced by the initial backups to the source DL to the target DL. This is done by seeding the target DL with the same data as on the source DL so that only the minimum amount of data needs to be transferred between units on subsequent duplication operations to maintain synchronization. The source and target DLs should not be put into production until this seeding process is complete. Seeding is considered complete when the duplication window has been demonstrated to have been met.

There are a number of options that can be employed to accomplish this:

• OPTION 1: Locate the source and target DL so that they are on a dedicated Ethernet network and optimized duplication occurs locally for at least two full backups per disk pool in this local configuration. If time savings are not seen over the time it takes to perform a regular NetBackup duplication to the target DL (that is, utilizing the media server), further local copy operations may be needed to ensure the target system has sufficient data. (That is, when the data transferred by subsequent copy operations is more representative of the quantity of data that the DL will typically


replicate within the window.) When the seeding completes, the target DL can be deployed to its intended location.

• OPTION 2: Locate the source and target DL so that they are both connected to the backup server, and use the backup server to write the data from at least two full backups to each disk pool in both the source and target DL using a normal NetBackup backup operation. Deploy the target DL to its intended location.

• OPTION 3: Use tape to seed the data in the target DL. Using the tapes from at least two full backups present on the source DL, write the data to disk volumes on the target DL Unless the tape copy was performed by NetBackup, NetBackup will not know about the copy. Deploy the target DL to its destination.

If optimized duplication does not occur until multiple images are ingested by the source DL, there will be a large number of unique blocks on the source DL that will need to be transferred over the network. In this situation, all the unique blocks must be sent over the network and there may be a significant delay before the data in the two systems is synchronized.

When deploying the target DL to its intended location, set the storage unit “maximum concurrent jobs” parameter to zero for the storage unit specified for the source image so that any optimized duplication jobs that may occur will queue instead of fail. If an optimized duplication job fails, NetBackup will retry the job using its normal duplicate process placing the copy load on the media server. When the target DL is in place, change the “maximum concurrent jobs” parameter to its normal setting so that any queued jobs can begin.

Performance considerations Replication performance of the deduplicated image depends on daily change rates between new backup data and data residing on the target system.

The higher the change rate, the more data that needs to be moved within the copy window. Lower than expected deduplication rates will add time to the copy and may exceed the required

copy window.

Effects of distance and latency Latency is the time it takes for a signal to propagate from one point to another. When the source and target sites are relatively close together, there will be little to no latency. Now, if those two sites are very far apart — say hundreds or thousands of miles — it is a different story. That same link is likely to produce only a fraction of the throughput as when the two sites were close together. It is the latency, introduced by the long distance, which degrades the performance.

Geographic distance is not the same as circuit distance. Actual circuit distance is often much larger than geographic distance. Geographic distance is the distance between two sites. Circuit distance is the length of the route the signal follows to get from one site to another. In addition, circuit distance also accommodates for switches, routers, repeaters, and other network devices that contribute to the distance latency value. Table 1 lists the theoretical maximum speed for several common link bandwidths. The second column is the wire speed. After subtracting network overhead, the last two columns show the effective, or potentially realizable, throughput with no latency. As distance is injected, latency increases and performance drops.

Table 1. Common link bandwidths

Link Wire speed (Mb/s) Effective bandwidth (MB/s) Effective bandwidth (GB/hr)

T1 1.5 0.16 0.6 T3 45 5 17 OC-3 100 11 39 OC-12 622 68 240 GbE 1250 110 385


Signals in copper and optical conductors have a finite velocity; they don't travel at the speed of light. It's closer to two-thirds the speed of light. The commonly used value for latency is 1 ms for every 200 km (125 miles). So to send data out of New York City to a storage facility in the Midwestern United States 1,000 miles away is a round-trip time of 16 ms. And the size of the pipe doesn't matter; a 1 Gb/s link and a T1 link (1.5 Mb/s) will both take 16 ms for the entire trip.

It is important to note that as latency increases, the bandwidth of the link does not become the limiting factor in replication speed.

Sizing considerations EMC strongly recommends performing a sizing assessment when including NetBackup optimized duplication in the backup environment. The sizing assessment can help determine if the DL can replicate the source image to the target system in the desired timeframe based on the network bandwidth, latency of the connection between the source and target systems, and estimated amount of data to copy on each day.

The sizing assessment models the replication performance of the DL and reports the replication times calculated for all days in the retention period for the source system. If the calculated replication times exceed the required copy window, additional source systems may be required. There are cases where a single source system meets capacity and ingest performance objectives, but not replication performance as replication performance is much lower than ingest and deduplication rates.

If optimized duplication fails for any reason, NetBackup 6.5.3 and earlier duplicate the source image using normal duplication operations. (With NetBackup 6.5.4 and later, this capability must be configured in the NetBackup master server.) With normal duplication, the undeduplicated image copies from source DL to target DL. If this occurs, sufficient capacity should be available (and accounted for) on the target system to receive the copy. The target DL will deduplicate the image as it is received.

Bi-directional optimized duplication, if used, needs to take into account the total unique TB being sent to each DL system from the respective source systems. This value is added to the actual capacity needed for the system.

The latest available DL sizing tools are available in a restricted location on Powerlink under the Disk Library product.

Configuring NetBackup optimized duplication There are three methods that can be used to perform NetBackup optimized duplication of deduplicated backup images from a source DL disk pool to a target DL disk pool. One method is to use the CLI to perform the duplication either manually or by writing a script that runs at a specific time.

The second method uses Storage Lifecycle Policies (SLP) to first back up an image to the DL and later use the DL to replicate the deduplicated image to another DL. Although this optimized duplication process is automated, it does not allow scheduling of when the duplication occurs, which the Vault option does allow. See the section “Storage Lifecycle Policies” on page 26 for more information.

The third method for duplicating backup images is to use the NetBackup Vault option. The Vault option allows you to schedule and automate the duplication process.

Optimized duplication has the following NetBackup limitations:

• Failure of an optimized duplication operation causes the duplication to be retried as a normal duplication in NetBackup 6.5.3 and earlier. (With NetBackup 6.5.4 and later, this capability must be configured in the NetBackup master server.)

An optimized duplication job initiated by a storage lifecycle policy that fails causes the storage lifecycle policy to retry that operation as an optimized duplication job only.


• To confirm the image copy, a media server initiating the optimized duplication must have connectivity

to the target DL.

CLI (bpduplicate) The NetBackup CLI command that is used for duplication is bpduplicate. This command can be run from either the master server or the media server.

The command syntax is explained in detail in the Veritas 6.5 NetBackup Commands for UNIX and Linux or Veritas 6.5 NetBackup Commands for Windows manuals available at the following URLs, respectively:



When using bpduplicate, searches can be performed to find backup IDs to be duplicated based on:

• Client name • Policy name • Policy type • Backups written by a specific server • Schedule type

There are numerous ways to specify which backups should be duplicated. These include:

• Backup IDs may be specified individually. • A file can list all backup IDs to be duplicated. • Start and end times may be used to specify the range of dates and times that include all backups to

be duplicated. Among other things that may be specified within the bpduplicate command are the volume pool, the destination storage, unit and the retention period for the copies.

Storage Lifecycle Policies A second method for optimized duplication is to use Storage Lifecycle Policies (SLP). This method allows a policy to be created that specifies how a backup image is managed throughout its lifecycle. The policy can be configured to back up an image to the DL, then initiate duplication of the image to another DL. The SLP automates NetBackup optimized duplication although the current SLP implementation will kick off the duplication shortly after the backup completes.

More detailed information about using SLP can be found in the Veritas NetBackup 6.5 System Administrator’s Guide, Volume 1 for UNIX and Linux or the Veritas NetBackup 6.5 System Administrator’s Guide, Volume 1 for Windows, which are available at the following URLs, respectively:



SLP configuration is accomplished through the NetBackup Administration Console.

1. In the NetBackup Administration Console, select NetBackup Management > Storage > Storage Lifecycle Policies.

2. Click Actions > New > New Storage Life Cycle Policy. For example, newlifecycle is the name given to the new Storage lifecycle policy as shown in Figure 14.






Figure 14. Create a new storage lifecycle policy

3. Click Add. Make sure the Backup radio button is selected and choose the storage unit that can write to the source disk pool on the source DL as shown in Figure 15 and click OK. The alternate read server should not be selected.

Figure 15. Storage unit defined for the source DL

4. Click the Add button again on the New Storage Lifecycle Policy dialog screen (Figure 14). Make sure the Duplication radio button is selected and specify the storage unit for the media server that can write to the target disk pool as shown in Figure 16 and click OK. Again, the alternate read server should not be selected.


Figure 16. New storage destination for duplication

The storage destination created as part of the backup and duplication as shown in Figure 15 and Figure 16, respectively, are displayed in the Storage destinations list box as shown in Figure 17.

Figure 17. SLP with backup and duplication defined

5. Select a Storage Lifecycle Policy (Figure 18). The policy has to be activated and run manually or scheduled to be used.


Figure 18. Selecting a Storage Lifecycle Policy

Vault The third method for duplicating backup images is to use the NetBackup Vault option. The Vault option provides the ability to schedule and automate the duplication process, and track the media.

More detailed information about using Vault can be found in the Veritas NetBackup Vault 6.5 System Administrator’s Guide for UNIX and Windows, which is available at the following URL:




While any of the three methods (CLI, SLP, or Vault) discussed may be used for NetBackup optimized duplication, the automation provided by SLP or the NetBackup Vault option simplifies the task of making copies of an OST image. In addition the NetBackup Vault option allows scheduling when the NetBackup optimized duplication operation occurs.

Disaster recovery When optimized duplication occurs, NetBackup updates its catalog with the location of the duplicated copy. Because it is aware of it, performing a recovery using the copied image on the target DL is no different from recovering from any other duplicate job.

Since NetBackup, by default, always uses the primary copy for a recovery operation, it will be necessary to make the image to be recovered on the target DL the primary copy. This can be done using either the NetBackup GUI or CLI.

For more information on disaster recovery strategies, refer to Symantec’s Implementing Highly Available Data Protection with Veritas NetBackup white paper at the following URL:

http://eval.symantec.com/mktginfo/enterprise/white_papers/b-whitepaper_implementing_highly_available_dr_with_veritas_netbackup_01_08_13599373.pdf

Conclusion The configuration settings and best practices outlined in this white paper are intended to assist in maximizing performance of the Disk Library 1500/3000 when used in NetBackup OpenStorage (OST) environments. However, no two backup environments are exactly the same. Because of this, individual parameter and configuration settings may need to be varied to meet each specific environment’s requirements.

References • EMC DL1500 and DL3000 — Best Practices Planning white paper • EMC DL1500 and DL3000 Replication — Best Practices Planning white paper • Veritas NetBackup Administrator’s Guide, Volume I for Windows Release 6.5 • Veritas NetBackup Administrator’s Guide, Volume I for UNIX and Linux Release 6.5 • Veritas NetBackup Shared Storage Guide UNIX, Windows, Linux Release 6.5 • Veritas NetBackup Shared Storage Guide UNIX, Windows, Linux release 6.5.4 • Veritas NetBackup Vault Administrator’s Guide UNIX, Windows, Linux Release 6.5




EMC DL1500 and DL3000 with Veritas NetBackup OpenStorage (OST) · Configure the backup policy ......

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