NetBackup™ Backup Planning and Performance Tuning Guide

Last Published:
Product(s): NetBackup & Alta Data Protection (10.4, 10.3.0.1, 10.3, 10.2.0.1, 10.2, 10.1.1, 10.1, 10.0.0.1, 10.0, 9.1.0.1, 9.1, 9.0.0.1, 9.0, 8.3.0.2, 8.3.0.1, 8.3)
  1. NetBackup capacity planning
    1.  
      Purpose of this guide
    2.  
      Changes in Veritas terminology
    3.  
      Disclaimer
    4.  
      How to analyze your backup requirements
    5.  
      How to calculate the size of your NetBackup image database
    6. Sizing for capacity with MSDP
      1. Key sizing parameters
        1.  
          Data types and deduplication
        2.  
          Determining FETB for workloads
        3.  
          Retention periods
        4.  
          Change rate
        5.  
          Replication and duplication of backups
        6.  
          Sizing calculations for MSDP clients
    7.  
      About how to design your OpsCenter server
  2. Primary server configuration guidelines
    1.  
      Size guidance for the NetBackup primary server and domain
    2.  
      Factors that limit job scheduling
    3.  
      More than one backup job per second
    4.  
      Stagger the submission of jobs for better load distribution
    5.  
      NetBackup job delays
    6.  
      Selection of storage units: performance considerations
    7.  
      About file system capacity and NetBackup performance
    8.  
      About the primary server NetBackup catalog
    9.  
      Guidelines for managing the primary server NetBackup catalog
    10.  
      Adjusting the batch size for sending metadata to the NetBackup catalog
    11.  
      Methods for managing the catalog size
    12.  
      Performance guidelines for NetBackup policies
    13.  
      Legacy error log fields
  3. Media server configuration guidelines
    1. NetBackup hardware design and tuning considerations
      1.  
        PCI architecture
      2.  
        Central processing unit (CPU) trends
      3.  
        Storage trends
      4.  
        Conclusions
    2. About NetBackup Media Server Deduplication (MSDP)
      1.  
        Data segmentation
      2.  
        Fingerprint lookup for deduplication
      3.  
        Predictive and sampling cache scheme
      4.  
        Data store
      5.  
        Space reclamation
      6.  
        System resource usage and tuning considerations
      7.  
        Memory considerations
      8.  
        I/O considerations
      9.  
        Network considerations
      10.  
        CPU considerations
      11.  
        OS tuning considerations
      12. MSDP tuning considerations
        1.  
          Sample steps to change MSDP contentrouter.cfg
      13. MSDP sizing considerations
        1.  
          Data gathering
        2.  
          Leveraging requirements and best practices
    3.  
      Cloud tier sizing and performance
    4. Accelerator performance considerations
      1.  
        Accelerator for file-based backups
      2.  
        Controlling disk space for Accelerator track logs
      3.  
        Accelerator for virtual machine backups
      4.  
        Forced rescan schedules
      5.  
        Reporting the amount of Accelerator data transferred over the network
      6.  
        Accelerator backups and the NetBackup catalog
  4. Media configuration guidelines
    1.  
      About dedicated versus shared backup environments
    2.  
      Suggestions for NetBackup media pools
    3.  
      Disk versus tape: performance considerations
    4.  
      NetBackup media not available
    5.  
      About the threshold for media errors
    6.  
      Adjusting the media_error_threshold
    7.  
      About tape I/O error handling
    8.  
      About NetBackup media manager tape drive selection
  5. How to identify performance bottlenecks
    1.  
      Introduction
    2.  
      Proper mind set for performance issue RCA
    3.  
      The 6 steps of performance issue RCA and resolution
    4. Flowchart of performance data analysis
      1.  
        How to create a workload profile
  6. Best practices
    1.  
      Best practices: NetBackup SAN Client
    2. Best practices: NetBackup AdvancedDisk
      1.  
        AdvancedDisk performance considerations
      2.  
        Exclusive use of disk volumes with AdvancedDisk
      3.  
        Disk volumes with different characteristics
      4.  
        Disk pools and volume managers with AdvancedDisk
      5.  
        Network file system considerations
      6.  
        State changes in AdvancedDisk
    3.  
      Best practices: Disk pool configuration - setting concurrent jobs and maximum I/O streams
    4.  
      Best practices: About disk staging and NetBackup performance
    5.  
      Best practices: Supported tape drive technologies for NetBackup
    6. Best practices: NetBackup tape drive cleaning
      1.  
        How NetBackup TapeAlert works
      2.  
        Disabling TapeAlert
    7.  
      Best practices: NetBackup data recovery methods
    8.  
      Best practices: Suggestions for disaster recovery planning
    9.  
      Best practices: NetBackup naming conventions
    10.  
      Best practices: NetBackup duplication
    11.  
      Best practices: NetBackup deduplication
    12. Best practices: Universal shares
      1.  
        Benefits of universal shares
      2.  
        Configuring universal shares
      3.  
        Tuning universal shares
    13. NetBackup for VMware sizing and best practices
      1.  
        Configuring and controlling NetBackup for VMware
      2.  
        Discovery
      3.  
        Backup and restore operations
    14. Best practices: Storage lifecycle policies (SLPs)
      1.  
        Data flow and SLP design best practices
      2.  
        Targeted SLP
      3.  
        Limiting the number of SLP secondary operations to maximize performance
      4.  
        Storage Server IO
    15.  
      Best practices: NetBackup NAS-Data-Protection (D-NAS)
    16.  
      Best practices: NetBackup for Nutanix AHV
    17.  
      Best practices: NetBackup Sybase database
    18.  
      Best practices: Avoiding media server resource bottlenecks with Oracle VLDB backups
    19.  
      Best practices: Avoiding media server resource bottlenecks with MSDPLB+ prefix policy
    20.  
      Best practices: Cloud deployment considerations
  7. Measuring Performance
    1.  
      Measuring NetBackup performance: overview
    2.  
      How to control system variables for consistent testing conditions
    3.  
      Running a performance test without interference from other jobs
    4.  
      About evaluating NetBackup performance
    5.  
      Evaluating NetBackup performance through the Activity Monitor
    6.  
      Evaluating NetBackup performance through the All Log Entries report
    7. Table of NetBackup All Log Entries report
      1.  
        Additional information on the NetBackup All Log Entries report
    8. Evaluating system components
      1.  
        About measuring performance independent of tape or disk output
      2.  
        Measuring performance with bpbkar
      3.  
        Bypassing disk performance with the SKIP_DISK_WRITES touch file
      4.  
        Measuring performance with the GEN_DATA directive (Linux/UNIX)
      5.  
        Monitoring Linux/UNIX CPU load
      6.  
        Monitoring Linux/UNIX memory use
      7.  
        Monitoring Linux/UNIX disk load
      8.  
        Monitoring Linux/UNIX network traffic
      9.  
        Monitoring Linux/Unix system resource usage with dstat
      10.  
        About the Windows Performance Monitor
      11.  
        Monitoring Windows CPU load
      12.  
        Monitoring Windows memory use
      13.  
        Monitoring Windows disk load
    9.  
      Increasing disk performance
  8. Tuning the NetBackup data transfer path
    1.  
      About the NetBackup data transfer path
    2.  
      About tuning the data transfer path
    3.  
      Tuning suggestions for the NetBackup data transfer path
    4.  
      NetBackup client performance in the data transfer path
    5. NetBackup network performance in the data transfer path
      1.  
        Network interface settings
      2.  
        Network load
      3. Setting the network buffer size for the NetBackup media server
        1.  
          Network buffer size in relation to other parameters
      4.  
        Setting the NetBackup client communications buffer size
      5.  
        About the NOSHM file
      6.  
        Using socket communications (the NOSHM file)
    6. NetBackup server performance in the data transfer path
      1. About shared memory (number and size of data buffers)
        1.  
          Default number of shared data buffers
        2.  
          Default size of shared data buffers
        3.  
          Amount of shared memory required by NetBackup
        4.  
          How to change the number of shared data buffers
        5.  
          Notes on number data buffers files
        6.  
          How to change the size of shared data buffers
        7.  
          Notes on size data buffer files
        8.  
          Size values for shared data buffers
        9.  
          Note on shared memory and NetBackup for NDMP
        10.  
          Recommended shared memory settings
        11.  
          Recommended number of data buffers for SAN Client and FT media server
        12.  
          Testing changes made to shared memory
      2.  
        About NetBackup wait and delay counters
      3.  
        Changing parent and child delay values for NetBackup
      4. About the communication between NetBackup client and media server
        1.  
          Processes used in NetBackup client-server communication
        2.  
          Roles of processes during backup and restore
        3.  
          Finding wait and delay counter values
        4.  
          Note on log file creation
        5.  
          About tunable parameters reported in the bptm log
        6.  
          Example of using wait and delay counter values
        7.  
          Issues uncovered by wait and delay counter values
      5.  
        Estimating the effect of multiple copies on backup performance
      6. Effect of fragment size on NetBackup restores
        1.  
          How fragment size affects restore of a non-multiplexed image
        2.  
          How fragment size affects restore of a multiplexed image on tape
        3.  
          Fragmentation and checkpoint restart
      7. Other NetBackup restore performance issues
        1.  
          Example of restore from multiplexed database backup (Oracle)
    7.  
      NetBackup storage device performance in the data transfer path
  9. Tuning other NetBackup components
    1.  
      When to use multiplexing and multiple data streams
    2.  
      Effects of multiplexing and multistreaming on backup and restore
    3. How to improve NetBackup resource allocation
      1.  
        Improving the assignment of resources to NetBackup queued jobs
      2.  
        Sharing reservations in NetBackup
      3.  
        Disabling the sharing of NetBackup reservations
      4.  
        Disabling on-demand unloads
    4.  
      Encryption and NetBackup performance
    5.  
      Compression and NetBackup performance
    6.  
      How to enable NetBackup compression
    7.  
      Effect of encryption plus compression on NetBackup performance
    8.  
      Information on NetBackup Java performance improvements
    9.  
      Information on NetBackup Vault
    10.  
      Fast recovery with Bare Metal Restore
    11.  
      How to improve performance when backing up many small files
    12. How to improve FlashBackup performance
      1.  
        Adjusting the read buffer for FlashBackup and FlashBackup-Windows
    13.  
      Veritas NetBackup OpsCenter
  10. Tuning disk I/O performance
    1. About NetBackup performance and the hardware hierarchy
      1.  
        About performance hierarchy level 1
      2.  
        About performance hierarchy level 2
      3.  
        About performance hierarchy level 3
      4.  
        About performance hierarchy level 4
      5.  
        Summary of performance hierarchies
      6.  
        Notes on performance hierarchies
    2.  
      Hardware examples for better NetBackup performance

When to use multiplexing and multiple data streams

For backup to tape, multiple data streams can reduce the time for large backups. The reduction is achieved by first splitting the data to be backed up into multiple streams. Then you use multiplexing, multiple drives, or a combination of the two for processing the streams concurrently. In addition, you can configure the backup so each physical device on the client is backed up by a separate data stream. Each data stream runs concurrently with streams from other devices, to reduce backup times.

Note:

For best performance, use only one data stream to back up each physical device on the client. Multiple concurrent streams from a single physical device can adversely affect the time to back up the device: the drive heads must move back and forth between tracks that contain the files for the respective streams.

Multiplexing is not recommended for database backups when restore speed is of paramount interest or when your tape drives are slow.

Backing up across a network, unless the network bandwidth is very broad, can nullify the ability to stream. Typically, a single client can send enough data to saturate a single 1Gb or 10Gb network connection. A gigabit network has the capacity to support network streaming for some clients. Multiple streams use more of the client's resources than a single stream. Veritas recommends testing to make sure of the following: that the client can handle the multiple data streams, and that the high rate of data transfer does not affect users.

Multiplexing and multiple data streams can be powerful tools to ensure that all tape drives are streaming. With NetBackup, both can be used at the same time. Be careful to distinguish between the two concepts, as follows.

Multiplexing writes multiple data streams to a single tape drive.

Figure: Multiplexing diagram shows multiplexing.

Figure: Multiplexing diagram

Multiplexing diagram

The multiple data streams feature writes multiple data streams, each to its own tape drive, unless multiplexing is used.

Figure: Multiple data streams diagram shows multiple data streams.

Figure: Multiple data streams diagram

Multiple data streams diagram

Consider the following about multiplexing:

  • Experiment with different multiplexing factors to find the one that is minimally sufficient for streaming.

    Find a setting at which the writes are enough to fill the maximum bandwidth of your drive: that setting is the optimal multiplexing factor. If you get 5 MB per second from each of the read streams, use a multiplexing factor of two to get the maximum throughput to an LTO 7 or LTO 8.

  • Use a higher multiplexing factor for incremental backups.

  • Use a lower multiplexing factor for local backups.

  • Expect the duplication of a multiplexed tape to take longer if it is demultiplexed (unless "Preserve Multiplexing" is specified on the duplication). Without "Preserve Multiplexing," the duplication may take longer because multiple read passes of the source tape must be made. Using "Preserve Multiplexing," however, may affect the restore time (see next bullet).

  • When you duplicate a multiplexed backup, demultiplex it.

    By demultiplexing the backups when they are duplicated, the time for recovery is significantly reduced.

Consider the following about multiple data streams:

  • Do not use multiple data streams on single mount points.

    The multiple data streams feature takes advantage of the ability to stream data from several devices at the same time. Streaming from several devices permits backups to take advantage of Read Ahead on a spindle or set of spindles in RAID environments. The use of multiple data streams from a single mount point encourages head thrashing and may result in degraded performance. Only conduct multistreamed backups against single mount points if they are mirrored (RAID 0). However, degraded performance is a likely result.