BPG00001A v11 DXi Best Practice Guide With Symantec NetBackup

7/29/2019 BPG00001A v11 DXi Best Practice Guide With Symantec NetBackup

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NetBackup 6.5, 7.0 and 7.1 from Symantec with DXi-Series

20020428-009 Rev A (BPG00001 V11)


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Table of Contents

DXi-Series Best Practices for NetBackup ................................................................... 1Scope ....................................................................................................................................... 1

Installation Recommendations .................................................................................... 2Virtual Tape Library Presentation: Fibre Channel .................................................................... 2Robot/Media Changer Device Serialization and Recommendations ................................................. 2

Links to Mapping Files and Supported Device by NetBackup ............................................................ 2Supported Hardware Compatibility List .............................................................................................. 2Virtual Tape Drive Device Description and Recommendation ........................................................... 3Fibre Channel SAN Zoning ................................................................................................................. 3DXi Tape Drive Emulations and Recommend Drivers ....................................................................... 4Number of Concurrent Tape Drives in Use ........................................................................................ 4Quantity and Capacity of Tapes ......................................................................................................... 5Suggested Tape Cartridge Capacity .................................................................................................. 5Tape Drive LUN Mapping ................................................................................................................... 6

Application Specific Path to Tape ....................................................................................................... 6Network Attached Storage Presentation: GbE ......................................................................... 6OpenStorage API Support........................................................................................................ 7Quantum Accent Support ......................................................................................................... 7Replication Recommendations ................................................................................................. 7

Integration Recommendations ..................................................................................... 8NetBackup with DXi Series Configuration Guide ............................................................................... 8

VTL - Fibre Channel ................................................................................................................. 8Performance Tuning ........................................................................................................................... 8

Eliminating Interference from the Host System ............................................................................................. 8Fragment Size for the Storage Unit ............................................................................................................... 8Performance Gains with Buffer Settings in NetBackup ................................................................................. 9Network Buffering For Windows Servers Overview .................................................................................... 10

DXi as Network Attached Storage .......................................................................................... 12General Best Practices for DXi as a NAS target. ............................................................................. 12 Network Attached Storage Settings and Tuning .............................................................................. 12

NFS/CIFS Recommended Mount Options ............................................................................. 12Sun Solaris NFS Settings ................................................................................................................. 13Linux NFS Settings ........................................................................................................................... 15IBM AIX NFS Client Settings ............................................................................................................ 16HP HP-UX NFS Settings .................................................................................................................. 16Testing the Source Data to Isolate Bottlenecks ............................................................................... 19

Utilization Recommendations .................................................................................... 20Deduplication Limitations ....................................................................................................... 20

Good Candidates for Data De-Duplication ....................................................................................... 20

Not So Good Candidates for Data De-Duplication ........................................................................... 20Space Reclamation ................................................................................................................ 20Recommended Handling of Expired Media ............................................................................ 20

Addi tional Information ................................................................................................ 21

Quantum Corporation 20020428-009 Rev A (BPG00001 V11) Page i


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DXi-Series Best Practices for NetBackup

Quantum Best Practices Guide for DXi-Series (DXi4500, DXi6500-Series, DXi6700, DXi6701/DXi6702,DXi7500-Series and DXi8500) and NetBackup by Symantec is provided to assist system administrators

and backup administrators in getting the most out of their investment. Quantums global field teams anddevelopment engineering teams contributed their expertise in creating these recommendations. TheQuantum Best Practices Guides are routinely updated to include the latest enhancements; check withyour Quantum sales team for the latest version.

Scope

The intended audience for this guide is our customers and field sales teams as guidance to enhance theinstallation, integration, and utilization of the Quantum DXi-Series. Specifically, this guide provides rec-ommendations and considerations impacting installing, integrating, and utilizing the DXi-Series productsspecifically for NetBackup by Symantec environments.

Quantum Corporation 20020428-009 Rev A (BPG00001 V11) Page 1


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Installation Recommendations

Virtual Tape Library Presentation: Fibre Channel

Robot/Media Changer Device Serialization and Recommendations

Quantum is a leading manufacturer of automation devices and extends this knowledge and experience tothe Virtual Tape Library (VTL) disk-based solutions. One of the key components to ensure that SAN-connected physical and virtual tape libraries are detected properly by backup servers is serialization.Serialization provides a unique identifier for each device in a physical or virtual tape library to automatedevice association from multiple backup servers. These identifiers, returned by the VTL devices, are sep-arate from the element address that defines the position of devices in the library. The element addressis used by the librarys robot or medium changer to manage the tape drives.

Serialization allows the servers running the data protection application (the media servers) to coordinatetape drive configuration by aligning the device serial number with the devices element address. Thisenables the data protection application to automatically discover the devices in the library during the de-vice discovery and configuration phase (e.g., the NetBackup Device Configuration Wizard), reducing thepotential for improper configuration. This feature enables Symantec NetBackup device discovery to align

these two addresses. If the Device Configuration Manager does not serialize the devices listed, do notcommit the changes, and check the VTL online state. The DXi VTL partition must be online for this tofunction properly.

The Quantum recommended device identification for each DXi system is the native mode (e.g., use theDXi6700, DXi7500 or DXi8500 inquiry response string as the identification for each model respectively).This allows product identification for the service teams at both Symantec and Quantum. When using thenative device mode, Windows environments will display the device in the device manager as an unknownmedia changer. This is normal and not an error or problem to NetBackup. If the customer environmenthas requirements for a specific changer device for compatibility, the Quantum DXi products support emu-lation of many popular devices to meet those requirements.

Please note NetBackup requires that VTLs be configured with the native inquiry string. Emulation stings

are not supported.

Quantum recommends installing NetBackups latest device mapping file to support properly identifyingdevices in NetBackup.

Links to Mapping Files and Supported Device by NetBackup

Links to current device mappings files are located in the Hardware Compatibility List or at the locationsbelow.

Windows platforms:

Linux/UNIX platforms:

Supported Hardware Compatibility List

NetBackup enterprise server hardware compatibility list:

http://www.symantec.com/business/support/index?page=landing&key=15143

http://www.symantec.com/business/support/index?page=landing&key=15143http://www.symantec.com/business/support/index?page=landing&key=15143http://www.symantec.com/business/support/index?page=landing&key=15143


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Virtual Tape Library operation can be tested with the robtest utility included with NetBackup. Details ofthe robtest utility can be downloaded form the NetBackup support site:http://seer.entsupport.symantec.com/docs/274063.htm

Virtual Tape Drive Device Descrip tion and Recommendation

Quantum DXi products support multiple tape drive emulations and allow user-definable capacities of tapecartridges to support the drive type. The drive type selection does not internally impose any throttling ofthe ingest rate. The host system uses tape device drivers to communicate with the virtual tape drives andthe NetBackup application. The qualified tape drive emulations published on the hardware compatibilitylist are HP and IBM LTO drives which have the widest support across platforms.

Quantum recommends using the Symantec tape drive drivers for backup hosts running the Windows 32-bit operating systems. For backup hosts running the 64-bit versions of the Windows operating system, theOEM tape device drivers are recommended. Symantecs complete tape drive driver recommendationscan be located in their hardware compatibility list (see above). Quantum recommends against using theWindows update function to get the latest tape drive drivers, as it is possible that Windows Update canfind unexpected driver matches for a tape drive. These unexpected matches often are not the same asthose supplied by the tape drive manufacturer and may introduce unexpected incompatibilities. This canresult in a change to the device in the Windows Device Manager.

Fibre Channel SAN Zoning

There are several different approaches to zone a Fibre Channel SAN for a variety of different SAN ob-jects. The best practice for zoning a single backup server or a group of backup servers to connect to asingle shared backup target could become quite complex. If the backup server consists of two or moreFibre Channel nodes, a single object such as a tape drive could possibly be presented to the backupserver multiple times. The Fibre Channel Host Bus Adaptor (HBA) is normally configured as a SAN initia-tor because the request for a dialog or transaction is normally initiated by the backup server via the FCHBA. The object that receives the signal from the SAN Backup initiator is called the SAN Backup Targetor SAN Target.

Implementing a SAN zone dictates that the SAN Initiator Node or port on the HBA is assigned to a zonethat speaks to only one target Node or port is called a Single Initiator Zoning method.

By implementing Single Initiator Zoning, an administrator will have a much greater flexibility (and confi-dence) with adds, moves, and changes as each Initiator is separately zoned and changes won't affectother Initiator/Target combos in the same fabric. The following illustration shows a Single Initiator Zoningmethod across multiple servers that contain 2 FC Nodes / ports.

http://seer.entsupport.symantec.com/docs/274063.htmhttp://seer.entsupport.symantec.com/docs/274063.htmhttp://seer.entsupport.symantec.com/docs/274063.htm


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Notice that a single FC Node could reside in multiple zones. This is due to the fact that it has multipletargets to contact.

DXi Tape Drive Emulations and Recommend Drivers

All drive types are tested by Quantum, and any limitations are listed below:

DLT7000: Use the Symantec driver or OEM driver

SDLT 600 and DLT-S4: Use the Symantec driver or OEM driver

HP LTO drives: Use the Symantec driver or OEM driver

IBM LTO drives: IBM Driver 6.1.5.4 with DPO function for 64-bit systems

Please note: Quantum does not support mixing drive types in a single partition.

Number of Concurrent Tape Drives in Use

Each DXi model has a maximum number of virtual tape drives that can be configured.Each DXi modelhas a maximum aggregate throughput rate that will be divided relatively equally between the virtual tapedrives in use. That does not prohibit a single tape drive from utilizing all available bandwidth. The mediaserver typically determines individual tape drive performance.

It is not a good idea to configure the maximum number of virtual tape drives and to perform I/O through allof them concurrently. Better performance can be achieved by using a subset of those virtual tape drivesat the same time. Quantum expects the customer configuration to distribute those virtual tape drives



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among multiple media servers to simplify initial installation by providing dedicated resources to each me-dia server. Quantum recommends that backups be staggered such that only a subset of drives are in useat one time. During a backup the data transfer rate is primarily controlled by the media server becausethe DXi system does not restrict the ingest data rate. This creates the opportunity for one or more mediaservers to burst data at a higher rate, leaving the remaining virtual tape drives less bandwidth. Converse-ly, it supports the coexistence of fast data streams with slow streams for maximum utilization of the avail-able bandwidth.

Note: Increasing the number of concurrently active virtual tape drives does not increase the aggregateDXi bandwidth and could result in a failed backup job due to a timeout from a bandwidth-starved opera-tion.

The table below lists the recommended maximum number of concurrently active virtual tape drives for therespective system bandwidth.

DXi ModelMaximum

Virtual TapeDrives

Maximum AggregateBandwidth

Recommended Maximum Number ofConcurrently-Acti ve Virtual Tape Drives

DXi6700 80 3.5TB/Hr or 972 MB/sec Up to 48 concurrently-active virtual tape drives **

DXi6701/DXi6702 80 5.8TB/Hr or 1610 MB/sec Up to 80 concurrently-active virtual tape drives **

DXi7500 Express 80 1.28TB/Hr or 355 MB/sec Up to 17 concurrently-active virtual tape drives **DXi7500 Enterprise 160 4TB/Hr or 1,111MB/sec Up to 55 concurrently-active virtual tape drives **

DXi8500 160 6.4TB/Hr or 1,777MB/sec Up to 88 concurrently-active virtual tape drives**

** Based on a user wanting no less than20 MB/sec per virtual tape drive.

Quantity and Capacity of Tapes

Quantum suggests not oversubscribing the device capacity when initially creating tape cartridges, andrecommends that the DXi installation team show the customer how to create additional virtual tape car-tridges to be added as needed. This recommendation is to assist the user with managing the availablespace on the DXi device. The initial number of tapes to create should be based on the sizing exerciseperformed by the Quantum System Engineer.

The DXi system can send alerts when the unit detects the user-selectable capacity point. Quantum re-commends this feature be configured and utilized to alert the user before unknowingly arriving at a low-space condition. When the backup environment requires additional virtual tapes cartridges and there issufficient space available, the user can add additional virtual tape cartridges to a partition and run an in-ventory to update the NetBackup database.

Suggested Tape Cartridge Capacity

Space on tape cartridges cannot be reused until all backup data on that cartridge has expired. The great-er the cartridges capacity, the longer it typically takes for all data on that cartridge to expire. Expired datacontinues to take up space on the virtual tape cartridge as well as in the DXi. Having tape cartridges witha lesser capacity is more desirable because tapes are returned to the scratch pool for reuse sooner.

There is virtually no relationship between the configured capacity of a virtual tape cartridge and the tapedrive emulation that has been configured for the partition:

Any backup/restore operation will span the number of tapes required, ignoring the configured ca-pacity.

Any vaulting/duplicating operation performed by the backup application will ignore the virtual ca-pacity when writing to another cartridge, whether virtual or physical.

DXi8500, DXi7500, DXi6700 and DXi6701/DXi6702 will limit you to the maximum capacity permit-ted by the tape drive emulation; the minimum is 5GB.



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Be aware that capacity utilization for DXi8500, DXi7500, DXi6700 and DXi6701/DXi6702 istracked in COMPRESSED GB and the data is stored compressed. That is, 100GB of data thatis 2:1 compressible will report that it occupies 50GB of virtual tape cartridge space.

If Application Specific Path to Tape is utilized, the ultimate cartridge destination size is the suggestedsize.

Quantums general guidance is to specify a smaller virtual tape cartridge capacity (such as 100GB) forthe reasons mentioned above.

Tape Drive LUN Mapping

Quantum recommends mapping the device starting with LUN 0 on each port and not skipping any LUNs.

Quantum recommends a best practice of zoning the VTL devices and the NetBackup media servers toprevent other servers from taking control of the VTL resources. Additionally, Quantum recommends usingthe HBA driver to bind the devices to a specific address. This helps keep devices in the same order aftera reboot.

Quantum DXi-Series VTL devices support reserve and release to accommodate the SSO NetBackup op-tion. The option allows devices to be shared between media servers. The advantage is having a pool ofdrives available to each media server. Other SAN architectures assign drives to each media server andeliminate the shared function. For both conditions, it is a good practice to keep the NetBackup mediaserver separate from the production server to eliminate downtime from maintenance. This requires themedia servers to have a fast network connection to the source data.

Appl ication Speci fi c Path to Tape

When creating physical tapes from virtual tapes in a DXi8500, DXi7500, DXi6700 and DXi6701/DXi6702users have two options:

Cloning tapes through the NetBackup Media Server, or

Using the DXi Application Specific Path to Tape option in conjunction with NetBackup "Direct to

Tape" functionUsing the Application Specific Path to Tape combined with Direct to Tape has important advantages forthe end user. The process creates physical media from the data stored on virtual tapes using a dedicatedFibre Channel connection and a directly connected tape library. The data is moved by the DXi, and doesnot use the resources of the Media Server, freeing the Media Server's resources for other operations. Butbecause the operation uses the NetBackup Direct to Tape utility to coordinate the data duplication, thereis a single point of management and the NetBackup catalog tracks the virtual and the physical tapes asseparate instances and allows the user to assign them different expiration policies. A user might, for ex-ample, decide to expire the disk based virtual tape copies after 60 days but retain the copy of the data onphysical tape for 24 months.The close integration of DXi and NetBackup also allows users to change media types and sizes whenthey move from virtual to physical while maintaining a single point of management--data from severalsmall virtual cartridges, for example, might be consolidated onto a single, larger physical piece of media.

For details see the Quantum DXi8500, DXi7500 and DXi6700: Symantec NetBackup Application Spe-cific Configuration Guide6-66537-xxx).Network Attached Storage Presentation: GbE

The Quantum Network-Attached Storage (NAS) appliance is intended to act as a target for backup appli-cations. This includes Network-Attached Storage or shares. NetBackup can use the NAS shares as DiskStorage Units (DSUs).



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Note: The NAS shares created on the DXi system are not recommended for general-purpose storage.

Quantum DXi systems support both CiFS (Windows-based) and NFS shares. Each system can supportmultiple NAS shares with a maximum of 128 shares. Quantum recommends that users create only therequired number of shares for each media server. DXi systems can support concurrent NFS and CiFSshares and can support Fibre Channel VTLs concurrently with those NFS and CiFS shares.

When using NAS shares on the DXi systems, Quantum recommends creating at least one share for eachmedia server to use. Media servers should not share the NAS shares during normal backup operations.

Root access to an NFS share is not allowed, and the access rights will be changed to nfsnobody as asecurity precaution. This does not impact access to the share from the NetBackup application.

OpenStorage API Support

The integration of Symantec's OpenStorage (OST) API initiative with Quantum's DXi4500, DXi6500 Se-ries, DXi6701/DXi6702, DXi7500 and DXi8500 disk backup, deduplication, and replication solutions pro-vides end users with a highly optimized solution for managing backup data across multiple locations andstorage tiers. The DXi's OST support allows users to set up Storage Servers and Logical Storage Units

(LSUs) on the DXi units, and to use NetBackup to duplicate data between DXi-based LSU's in differentlocations, providing disk-to-disk DR protection while leveraging the DXi's deduplication technology todramatically reduce network bandwidth requirements. Beginning with NetBackup 6.5.4, the DXi6540,DXi6550, DXi6701/DXi6702, DXi7500 and DXi8500 also provide support for the OST Direct to Tape func-tionality. This will allow users to move data written to DXi-based LSUs directly to a tape library using thedata movement resources of the DXi while NetBackup manages the data on disk and tape with indepen-dent retention policies.

For complete details, refer to Symantec's OST documentation, and Quantum Configuration Guides:Quantum DXi-Series Symantec NetBackup OST Configuration Guide 6-67079-xx

DXi Accent Support

Designed for bandwidth-constrained environments, DXi Accent dramatically increases backup perfor-mance using a hybrid-mode workflow to move part of the deduplication process to the backup server sothat only new blocks in each backup are sent to the appliance.

For complete details on configuration of Netbackup with Accent, refer to Quantum Configuration Guides:Quantum DXi-Series Symantec NetBackup OST Configuration Guide 6-67079-xxDXi-Series Configuration Guide with NetBackup PN 20020429-xxx

Replication Recommendations

For first-time replication setup, it is important to manually replicate the name space once the target sys-tem is configured and is online. This facilitates the first replication following the first backup to thatshare/partition. The replication is only available to VTL and NAS shares with de-duplication enabled. TheDXi supports 128-bit AES encryption for replication. Data is only encrypted while in transit between repli-cation source and replication target. Data is unencrypted upon arrival at the replication target. Encryptionmay affect replication performance. It should be disabled if the customers WAN is already secured.

Please refer to the Quantum DXi-Series Best Practices for Data Replication (Document 20020430-xxx).



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Integration Recommendations

NetBackup with DXi Series Configuration Guide

The NetBackup with DXi Series Configuration Guide contains additions additional information about con-figuring solutions with NetBackup (see the DXi-Series Configuration Guide with NetBackup PN

20020429-xxx)

VTL - Fibre Channel

Performance Tuning

Combining our in-house testing, partner information sharing and customer feedback, we have found en-hanced performance for NetBackup environments by using the following tuning parameters:

Eliminating Interference from the Host System

According to Microsoft: A conflict in Windows Server 2003 causes a Test Unit Ready (TUR) request is-

sue on SCSI-attached and fiber-attached devices. When this issue occurs, an overflow of TUR requestscauses the storage unit not to respond or to respond slowly to SCSI commands. In a SAN environment,any Windows Server 2003-based computer that is zoned to detect the Tape Backup Unit hardware cansend TUR requests. The cause and workaround are documented in the Microsoft knowledge base articlenumber 842411. Microsoft support link: (http://support.microsoft.com/kb/842411/en-us).

Fragment Size for the Storage Unit

Based on customer feedback and performance tuning, changing the fragment size for the storage unit inNetBackup from the default to 2000 balances backup and restore operations. The fragment size indicatesthe size for a single fragment before a file mark is inserted. When restoring a file, the operation mustsearch the full fragment. Using the smaller size allows the operation to search a limited area of the back-up.

http://support.microsoft.com/kb/842411/en-ushttp://support.microsoft.com/kb/842411/en-us


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Figure 1. Fragment Size Change

Performance Gains with Buffer Settings in NetBackup

Three main settings in NetBackup have been shown to have a major performance impact for backups:the size of the data buffer, the number of the data buffers, and the size of the network data buffers.

SIZE_DATA_BUFFERS

After changing this value, it is important to test both backups and restores, because sometimes data canbe written at the modified size but potentially cannot be read at the modified size. Our lab environmenttesting and field experience has been positive using the recommended 262,144 block size.

To change the SIZE_DATA_BUFFERS setting:

1. Create a file called SIZE_DATA_BUFFERS in the \\NetBackup\\db\config.

Note: The file name is case sensitive and must have no extension.

2. Add the value 262144 in this file.

Note: If the file is not present, the default value for the SIZE_DATA_BUFFER is 65,536.

Windows-specific guidance to use 256K block size: Windows Server 2003 requires that SP2 be installed;otherwise, the maximum allowed is 64K.

After this file is created you do not have to cycle any services. The change will be done when the nextbackup job starts.

In combination with the change in block size, the number of buffers used will impact overall system per-formance. The default setting for the number of buffers used is 16. Increasing the number of buffers al-



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lows more data to be buffered before being sent to the device. Our lab testing has yielded better resultsusing 32 for the number of buffers.

NUMBER_DATA_BUFFERS

To change the NUMBER_DATA_BUFFERS setting:

1. Create the


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From the NetBackup Administration console, Host Properties | Clients, double-click the client youare configuring.

Expand the options underWindows Client | select Client Settings. Change the Communicationsbufferto the desired size in KB.

Figure 2. Communication Buffer Size

For additional information on the settings, see our partner site link:http://support.veritas.com/docs/244652

http://support.veritas.com/docs/244652http://support.veritas.com/docs/244652http://support.veritas.com/docs/244652


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DXi as Network Attached Storage

General Best Practices for DXi as a NAS target.

In Windows Active Directory environments, the share acts as the target for the NetBackup MediaServer. The share is not intended as primary storage or drag-and-drop storage. A best practice is

to create a new account and workgroup as opposed to joining the domain to limit the access andprevent accidental file deletion by another user. Quantum recommends users not reconfigure ordelete NAS shares while data is being written. There is no mechanism to detect the I/O and pro-vide a warning to the user.

Use a dedicated network for backup data or use QoS features that guarantee network bandwidth.Another option would be to use virtual networks (VLANs) to segregate backup from productionnetwork traffic.

Configure network interface cards (NICs) in servers, clients and set routers to full duplex.

Use only CAT 5e or CAT 6 cables (1Gb/s rated cables).

If using a DNS server, verify the DNS server configuration settings are correct using nslookup onthe host name as well as the IP address

It is also a good idea to add the HOST NAME and IP Address to the host file

Use multiple DXi ports when connecting to the network. The more DXi Ports used the better theperformance capability will be across the ports.

For redundancy, connect a least two DXi ports to an Ethernet switch.

Set each switch port used by the DXi to auto-negotiate/auto-sensing. The DXi network interfacecards are preset to auto/auto and cannot be changed.

Network Attached Storage Settings and Tuning

If you experience slow performance on disk storage units and disk staging storage units, implement thefollowing recommendations:

Increase the data buffers used by Symantec NetBackup disk manager process on the master and mediaservers. The Default value is set to 262144 (256K).

Create a file /usr/openv/netbackup/db/config/SIZE_DATA_BUFFERS_DISK Add thevalue 1048576 to the file content. Note: The file name is case sensitive.

Create a file /netbackup/db/config/NUMBER_DATA_BUFFERS_DISK Add the value16 to the file. This can be increased based on available memory.

NFS/CIFS Recommended Mount Options

The following additional mount options are recommended for all NFS clients:

Use NFSv3, not NFSv2.

Do not use sync or noac mount options.



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Use the largest rsize/wsize that both the client and server support since the client and serverwill negotiate down. Use 1048576 (the default for many clients) since this is the maximumsupported by DXi.

1. Mount with rsize/wsize set to 1M.

mount o ver s=3, t cp, rsi ze=1048576, wsi ze=1048576

2. Verify the mount options by running the command cat /proc/mounts

NOTE: The older versions of Linux (pre-2.6.16) only support maximum of 32K rs-ize/wsizes that are not optimal. 2.6.18 and recent versions showed better performance.

Sun Solaris NFS SettingsNOTE: The commands are based on Solaris 10 client.

Solaris# uname aSunOS 5.10 Sun 4u Sparc SUNw Sun-Fire-v245

Step # Solaris TCP/IP Settings

1 For OST configurations; 8M buffer size is recommended for DXi software versions 1.4.3 and later. Thebuffer size for earlier versions was 4M. For the most current information and tuning details, please referto the following documents:

OST Plug-in Installation Instructions. 6-67074-xxQuantum DXi-Series Symantec NetBackup OST Configuration Guide 6-67079-xx

2 For NAS configurations set socket buffer size to 4M.Solaris# ndd set /dev/tcp tcp_xmit_hiwat 4194304Solaris# ndd set /dev/tcp tcp_recv_hiwat 4194304Solaris# ndd set /dev/tcp tcp_max_buf 4194304Solaris# ndd set /dev/tcp tcp_cwnd_max 2097152

NOTE: 1M and 4M are both fine. Also, as per Solaris documentation, some of these can be added in/etc/system file for persistence.set tcp:tcp_xmit_hiwat = 4194304set tcp:tcp_recv_hiwat = 4194304

NOTE: Set the socket buffers before doing mounts from clients. If they are already mounted, clients need tounmount and remount for the settings to take place. The unmount and remount may be done after theclient is fully configured.

3.Verify the settings by issuing the command

ndd get /dev/tcp tcp_recv_hiwat



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4OPTIONAL. If your client has multiple NICs bonding can be beneficial.

Create Link aggregation group with LACP.

Solaris# dladm create-aggr d bge0 d bge1 1Solaris# ifconfig aggr1 unplumbSolaris# dladm modify-aggr P L4 l active 1

Solaris# ifconfig aggr1 plumb netmask up

Verify the settings by issuing the commands:

dladm show-aggrdladm show-aggr -L

Step# Solaris NFS Client Settings

1Add the following lines to /etc/system to support > 32K rsize/wsize.

set nfs:nfs3_bsize=1048576set nfs:nfs3_max_transfer_size=1048576set nfs:nfs3_max_threads=32set maxphys=1048576

NOTE: this step needs a reboot, prior to mounting (step 3 below).

2.Maximize parallelism between an NFS client and its servers; set the following in the /etc/system file

set rpcmod:clnt_max_conns = 8

3.Mount with rsize/wsize set to 1M.

mount o vers=3,tcp,rsize=1048576,wsize=1048576

NOTE: If the settings in Step 3 are executed correctly, the default rsize, wsize should be 1M without a needfor specifying in the mount command.

NOTE: forcedirectio may not be available on all versions of Solaris

4.Verify the actual rsize and wsize.

nfsstat m

5.Maximize the contiguous blocks on the NFS share with the following command

tunefs a 256 /



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Linux NFS Settings

Step # Linux TCP/IP Settings

1 For OST configurations; 8M buffer size is recommended for DXi software versions 1.4.3 and later. Thebuffer size for earlier versions was 4M. For the most current information and tuning details, please refer

to the following documents:OST Plug-in Installation Instructions. 6-67074-xxQuantum DXi-Series Symantec NetBackup OST Configuration Guide 6-67079-xx

2For NAS configurations set socket buffer settings to 4M default. Append these lines to /etc/sysctl.conf

net.ipv4.tcp_rmem = 4194304 4194304 4194304net.ipv4.tcp_wmem = 4194304 4194304 4194304net.ipv4.tcp_mem = 10485760 10485760 10485760net.core.netdev_max_backlog = 30000

Run the commandsysctl p for the newly added configuration to take effect.

Verify the configuration by running sysctl net.ipv4.tcp_rmem, it should show4194304 4194304 4194304.

Note: Set the socket buffers before doing mounts from clients. If they are already mounted, clients need tounmount and remount for the settings to take place. The unmount and remount may be done after the clientis fully configured.

3OPTIONAL. If your client has multiple NICs bonding can be beneficial.

Create Link aggregation group with LACP

And add bonded round robin policy by adding this line in /etc/modprobe.conf:options bonding mode=6 miimon=500

[NOTE: During this testing, in lieu of LACP, Layer3+4 xmit_hash policy was also successfully used to re-

duce TCP retransmissions.

In the /etc/modprobe.conf, add the lineoptions bonding mode=2 xmit_hash_policy=layer3+4 miimon=500

NOTE: this step needs a reboot.

Step# Linux NFS Client Settings

1Mount with rsize/wsize set to 1M. This testing almost always had at least 4 mounts to the DXI. Eachmount was to one unique IP address.


NOTE: The older versions of Linux (pre-2.6.16) only support maximum of 32K rsize/wsizes that are not op-timal. 2.6.18 and recent versions showed better performance.

2Verify the mount options by running the command

cat /proc/mounts



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IBM AIX NFS Client Settings

Step# AIX Ethernet Interface Settings

1.Configure the Ethernet channel by using the smit etherchannel command.

OPTIONAL. If your client has multiple NICs bonding can be beneficial.

Step # AIX TCP/IP Settings

1Change socket buffer settings to 4M default.

Append these lines to /etc/sysctl.conf/usr/sbin/no -o tcp_sendspace=4194304/usr/sbin/no -o tcp_recvspace=4194304

To make them permanent, add the following lines into the /etc/rc.net file:/usr/sbin/no -o tcp_sendspace=4194304

/usr/sbin/no -o tcp_recvspace=4194304

Step# AIX NFS Client Settings

1Mount with rsize/wsize set to 1M.


NOTE: The AIX in the test ignored the rsize, wsize and defaulted to 65536

HP HP-UX NFS Settings

Step # HPUX TCP/IP Settings

1Change socket buffer settings to 4M default.

# ndd -set /dev/tcp tcp_recv_hiwater_def 4194304# ndd -set /dev/tcp tcp_xmit_hiwater_def 4194304

To make the changes permanent add the following lines to the /etc/rc.config.d/nddconf file and issue thecommand ndd c to activate the changes:TRANSPORT_NAME[0]=tcpNDD_NAME[0]=tcp_recv_hiwater_defNDD_VALUE[0]=4194304TRANSPORT_NAME[1]=tcpNDD_NAME[0]=tcp_xmit_hiwater_defNDD_VALUE[0]=4194304

2 OPTIONAL. If your client has multiple NICs bonding can be beneficial.

See HP-UX System Administration documentation.



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Step # HPUX NFS Client Settings

1In order to support greater than the default maximum of 32K rsize/wsize do the following:.

# kctune nfs3_bsize=1048576# kctune nfs3_max_transfer_size=1048576

# kctune nfs3_max_transfer_size_cots=1048576

confirm they were added to the Tunable entries section of the file /stand/system:# cat /stand/system

This change will take effect either after a reboot or after the NFS file systems are unmounted and re-mounted.

2Mount with rsize/wsize set to 1M.


3Verify the actual rsize and wsize.

nfsstat m

Microsoft Windows Settings

Step # Windows TCP/IP Settings

1 OST Configuration Options:

For the most current installation and tuning recommendations, please refer to the followingdocuments:OST Plug-in Installation Instructions. 6-67074-xxQuantum DXi-Series Symantec NetBackup OST Configuration Guide 6-67079-xx

2 CIFS Configuration Options:

Under Windows XP SP2, the "DefaultReceiveWindow" value in the AFD branch of the Registry takesprecedence over the RWIN values in the TCP branch. Under SP1, it is the other way around, the valuesin the TCP branch override the AFD value and go out in TCP packet headers.

Afd.sys is the kernel-mode driver that is used to support Windows Sockets applications. When there arethree default values, the default is calculated based on the amount of memory detected in the system:

The first value is the default for smaller computers (less than 19 MB).

The second value is the default for medium computers (64MB on Windows Server 2003).

The following values should be set to 16384 on larger backup servers, or the defaults based on the ma-chine sizes listed above.

HKEY_LOCAL_MACHINE \SYSTEM\CurrentControl Set\Services\Afd \Parameters

DefaultReceiveWindow



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Value Type: REG_DWORD

Default: 4096/8192/8192

The number of receive bytes that AFD buffers on a connection before imposing flow control.For some applications, a larger value here gives slightly better performance at the expense of

increased resource utilization. Applications can modify this value on a per-socket basis with theSO_RCVBUF socket option.

DefaultSendWindow

Value Type: REG_DWORD

Default: 4096/8192/8192

This is similar to DefaultReceiveWindow, but for the send side of connections.

Step# Windows CIFS Recommendations

1 On a Windows backup server using a DXi system and a CIFS share, you must change the

SESSTIMEOUT value from the default of 45 seconds to decimal 600 seconds (10 minutes).

Detailed background information on changing this value can be found here:http://support.microsoft.com/kb/102067/.

Workaround:

1. Go to Start>Run and type REGEDT32.

2. Open the Registry Key:

HKEY_LOCAL_MACHINE\SYSTEM\CURRENTCONTROLSET\SERVICES\LANMANWORKSTATION\PARAMTERS\

3. Locate the Key SESSTIMEOUT in the right panel.

NOTE: If the SESSTIMEOUT key does not exist: Click in the right panel and select New and DWORD val-ue. Create a new key, SESSTIMEOUT.

4. Change the value of the Key SESSTIMEOUT from 0 to 600.

Now all new Read append Operations will wait for 600 seconds before they Timeout. This gives the blockpoolenough time to reconstruct the data out of the blockpool.

http://support.microsoft.com/kb/102067/http://support.microsoft.com/kb/102067/


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Microsoft provides comprehensive guidelines for configuration and tuning for networks and storagein the documents referenced below.

Windows XP

ht t p: / / suppor t . mi cr osof t . com/ kb/ 314053/

Windows 2003

ht t p: / / downl oad. mi cr osof t . com/ downl oad/ 2/ 8/ 0/ 2800a518- 7ac6- 4aac- bd85-74d2c52e1ec6/ t uni ng. doc

Windows 2008

ht t p: / / downl oad. mi cr osof t . com/ downl oad/ b/ b/ 5/ bb50037f - e4ae- 40d1- a898-7cdf cf 0ee9d8/ WS08_STEP_BY_STEP_GUI DE/ WS08Per f or manceTuni ngGui de_En. docx

ht t p: / / downl oad. mi cr osof t . com/ downl oad/ 9/ c/ 5/ 9c5b2167- 8017- 4bae- 9f de-d599bac8184a/ Per f - t un- sr v. docx

Windows Vista

ht t p: / / downl oad. mi cr osof t . com/ downl oad/ c/ 2/ 6/ c26893a6- 46c7- 4b5c- b287-830216597340/ TCPI P_ Reg. doc

Testing the Source Data to Isolate Bott lenecks

The following commands show if bpbkar can read data from a hard disk. An even better use of this com-mand is for performance troubleshooting, because it is never possible to write to tape any faster than the

disk subsystem can produce it. The command shows how fast bpbkar can read data from the hard disk.

Note on command syntax: The "" is the path to the directories to back up, and "> /dev/null"is where the files list will be sent along with the report regarding the speed of reading data from the disk.

On UNIX systems:

./netbackup/bin/bpbkar -nocont > /dev/null

Example: ./netbackup/bin/bpbkar -nocont /home > /dev/null

On Windows systems:

.\netbackup\bin\bpbkar32 -nocont > NUL 2>temp.f

Example: .\netbackup\bin\bpbkar32 -nocont C:\ > NUL 2>temp.f

The starting point for reading data for the path in the Windows example is on C:\ and it will continue toread down all subdirectories. So C:\winnt is also valid, for example.

http://support.microsoft.com/kb/314053/http://download.microsoft.com/download/2/8/0/2800a518-7ac6-4aac-bd85-74d2c52e1ec6/tuning.dochttp://download.microsoft.com/download/2/8/0/2800a518-7ac6-4aac-bd85-74d2c52e1ec6/tuning.dochttp://download.microsoft.com/download/b/b/5/bb50037f-e4ae-40d1-a898-7cdfcf0ee9d8/WS08_STEP_BY_STEP_GUIDE/WS08PerformanceTuningGuide_En.docxhttp://download.microsoft.com/download/b/b/5/bb50037f-e4ae-40d1-a898-7cdfcf0ee9d8/WS08_STEP_BY_STEP_GUIDE/WS08PerformanceTuningGuide_En.docxhttp://download.microsoft.com/download/b/b/5/bb50037f-e4ae-40d1-a898-7cdfcf0ee9d8/WS08_STEP_BY_STEP_GUIDE/WS08PerformanceTuningGuide_En.docxhttp://download.microsoft.com/download/9/c/5/9c5b2167-8017-4bae-9fde-d599bac8184a/Perf-tun-srv.docxhttp://download.microsoft.com/download/9/c/5/9c5b2167-8017-4bae-9fde-d599bac8184a/Perf-tun-srv.docxhttp://download.microsoft.com/download/c/2/6/c26893a6-46c7-4b5c-b287-830216597340/TCPIP_Reg.dochttp://download.microsoft.com/download/c/2/6/c26893a6-46c7-4b5c-b287-830216597340/TCPIP_Reg.dochttp://download.microsoft.com/download/c/2/6/c26893a6-46c7-4b5c-b287-830216597340/TCPIP_Reg.dochttp://download.microsoft.com/download/c/2/6/c26893a6-46c7-4b5c-b287-830216597340/TCPIP_Reg.dochttp://download.microsoft.com/download/c/2/6/c26893a6-46c7-4b5c-b287-830216597340/TCPIP_Reg.dochttp://download.microsoft.com/download/c/2/6/c26893a6-46c7-4b5c-b287-830216597340/TCPIP_Reg.dochttp://download.microsoft.com/download/9/c/5/9c5b2167-8017-4bae-9fde-d599bac8184a/Perf-tun-srv.docxhttp://download.microsoft.com/download/9/c/5/9c5b2167-8017-4bae-9fde-d599bac8184a/Perf-tun-srv.docxhttp://download.microsoft.com/download/b/b/5/bb50037f-e4ae-40d1-a898-7cdfcf0ee9d8/WS08_STEP_BY_STEP_GUIDE/WS08PerformanceTuningGuide_En.docxhttp://download.microsoft.com/download/b/b/5/bb50037f-e4ae-40d1-a898-7cdfcf0ee9d8/WS08_STEP_BY_STEP_GUIDE/WS08PerformanceTuningGuide_En.docxhttp://download.microsoft.com/download/b/b/5/bb50037f-e4ae-40d1-a898-7cdfcf0ee9d8/WS08_STEP_BY_STEP_GUIDE/WS08PerformanceTuningGuide_En.docxhttp://download.microsoft.com/download/2/8/0/2800a518-7ac6-4aac-bd85-74d2c52e1ec6/tuning.dochttp://download.microsoft.com/download/2/8/0/2800a518-7ac6-4aac-bd85-74d2c52e1ec6/tuning.dochttp://support.microsoft.com/kb/314053/


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Utilization Recommendations

Deduplication Limitations

Deduplication results can be negatively impacted by compression, encryption, software deduplicationand, multiplexing. These functions all change the data stream in a way that obscures patterns in the data

content that will reduce the performance and deduplication from any downstream appliance including DXi.To obtain effective deduplication rates, users should NOT encrypt, deduplicate, compress, or multiplextheir backup data before sending it to a DXi appliance.

The use of multiplexing was intended for slow source data and a minimum transfer rate required by phys-ical tape drives. Multiplexing backup streams was intended to provide a more efficient use of a limitednumber of physical tape drives. Since the virtual tape drives in the DXi systems are not susceptible toperformance losses from slow data transfer rates, the number of virtual tape drives can easily be in-creased in quantity without any time penalty for re-positioning. It is not necessary to use multiplexing withthe DXi systems. Additionally, the multiplexing adds additional header information to the data lowering thededuplication ratio.

Good Candidates for Data De-Duplication

VMware, large databases (note exceptions below), PowerPoint presentations, Word documents, Excelspreadsheets, SQL, Oracle (note exceptions below), Exchange database, source code

Not So Good Candidates for Data De-Duplication

In-line compressed data, SQL with LiteSpeed (in-line compression), inline multiplexed data, Oracle withmulti-channel RMAN (in-line multiplex), and in-line encrypted data

For long-term archiving, Quantum recommends vaulting the data to a physical tape device.

Space Reclamation

Space management involves two processes: data reconciliation and data reclamation. Data reconciliationis used to create a list of what can be removed. It runs automatically every twelve hours at noon and mid-night, unless data reclamation is running. Data reclamation is the process of deleting the data on the datareconciliation list. It can be scheduled or run manually. There is significant overhead associated with thisprocess, and therefore it should not be run during periods of high appliance use. Replication, reclamation,and backup stream ingest all consume system resources, and consequently should not all be done at thesame time.

Quantum recommends scheduling daily reconciliation and reclamation to manage the available space.The scheduled time should be configured to start the data reclamation process after the daily backups arecomplete. The default schedule is weekly, and the default time for the data reclamation is set to 12:00AMSunday. These parameters are user configurable and should be configured for the customer backupwindow.

Recommended Handling of Expired Media

When a tape is expired by NetBackup, there is no direct communication of the event to the DXi-series.

The result is that a tape might be displayed as empty or SCRATCH to the NetBackup graphical Interface,but show the same tape on the DXi-series GUI as containing data. This indicates the data on the expiredtape is still using space on the DX-Series. To reclaim this space (for example, in an emergency low spacecondition), Quantum recommends using the bplabel utility. This will tell NetBackup to write a new label



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on the tape at the beginning of tape. This new label is a data block written to the virtual tape cartridge.The DXi-Series VTL will act similar to a physical tape and the data after the label becomes no longer ac-cessible. The space reclamation can be initiated by the scheduled time or started manually from the DXi-series GUI. Additional information about the reclamation process can be found in the DXi-Series usermanual.

Note: Running the bplabel utility on a tape will make the contents inaccessible. Make sure the tape is ex-pired before labeling the cartridge.

Addit ional Information Quantum web site:http://www.quantum.com

Symantec web site: http://www.symantec.com

Microsoft web site: http://www.microsoft.com

Guardian web site:http://www.quantum.com/ServiceandSupport/Services/GuardianInformation/index.aspx

StorageCare Vision web site:http://www.quantum.com/Products/Software/Storagecarevision/Index.aspx

Quantum Service web site: http://www.quantum.com/ServiceandSupport/Index.aspx

Call Center Americas. To contact our world-class support representatives, please refer to the in-formation below:

Telephone: 800-284-5101 (toll-free), 949-725-2100 (local/long distance)

Hours of operation (subject to change without notice): 7 days a week, 24 hours a day with va-lid contract

All other contracts can contact Quantum during normal business days from 5AM to 5PM USPacific Time.

View ourService Level Objective:http://www.quantum.com/ServiceandSupport/ServiceLevelAgreement/Index.aspx
http://www.quantum.com/http://www.quantum.com/http://www.quantum.com/http://www.microsoft.com/http://www.microsoft.com/http://www.quantum.com/ServiceandSupport/Services/GuardianInformation/index.aspxhttp://www.quantum.com/ServiceandSupport/Services/GuardianInformation/index.aspxhttp://www.quantum.com/Products/Software/Storagecarevision/Index.aspxhttp://www.quantum.com/Products/Software/Storagecarevision/Index.aspxhttp://www.quantum.com/ServiceandSupport/Index.aspxhttp://www.quantum.com/ServiceandSupport/ServiceLevelAgreement/Index.aspxhttp://www.quantum.com/ServiceandSupport/ServiceLevelAgreement/Index.aspxhttp://www.quantum.com/ServiceandSupport/ServiceLevelAgreement/Index.aspxhttp://www.quantum.com/ServiceandSupport/ServiceLevelAgreement/Index.aspxhttp://www.quantum.com/ServiceandSupport/ServiceLevelAgreement/Index.aspxhttp://www.quantum.com/ServiceandSupport/Index.aspxhttp://www.quantum.com/Products/Software/Storagecarevision/Index.aspxhttp://www.quantum.com/ServiceandSupport/Services/GuardianInformation/index.aspxhttp://www.microsoft.com/http://www.quantum.com/

Documents

BPG00001A v11 DXi Best Practice Guide With Symantec NetBackup