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

About tape I/O error handling

Note:

This topic has nothing to do with the number of times NetBackup retries a backup or restore that fails. That situation is controlled by the global configuration parameter Backup Tries for backups and the bp.conf entry RESTORE_RETRIES for restores.

The algorithm that is described here determines whether I/O errors on tape should cause media to be frozen or drives to be downed.

When a read/write/position error occurs on tape, the error that is returned by the operating system does not identify whether the tape or drive caused the error. To prevent the failure of all backups in a given time frame, bptm tries to identify a bad tape volume or drive based on past history.

To do so, bptm uses the following logic:

  • Each time an I/O error occurs on a read/write/position, bptm logs the error in the following file.

    Linux/UNIX

    /usr/openv/netbackup/db/media/errors

    Windows

    install_path\NetBackup\db\media\errors

    The error message includes the time of the error, media ID, drive index, and type of error. The following examples illustrate the entries in this file:

    07/21/96 04:15:17 A00167 4 WRITE_ERROR 
07/26/96 12:37:47 A00168 4 READ_ERROR

  • Each time an entry is made, the past entries are scanned. The scan determines whether the same media ID or drive has had this type of error in the past "n" hours. "n" is known as the time_window. The default time window is 12 hours.

    During the history search for the time_window entries, EMM notes the past errors that match the media ID, the drive, or both. The purpose is to determine the cause of the error. For example: If a media ID gets write errors on more than one drive, the tape volume may be bad and NetBackup freezes the volume. If more than one media ID gets a particular error on the same drive, the drive goes to a "down" state. If only past errors are found on the same drive with the same media ID, EMM assumes that the volume is bad and freezes it.

  • The freeze or down operation is not performed on the first error.

    Note two other parameters: media_error_threshold and drive_error_threshold. For both of these parameters, the default is 2. For a freeze or down to happen, more than the threshold number of errors must occur. By default, at least three errors must occur in the time window for the same drive or media ID.

    If either media_error_threshold or drive_error_threshold is 0, a freeze or down occurs the first time an I/O error occurs. media_error_threshold is looked at first, so if both values are 0, a freeze overrides a down. Veritas does not recommend that these values be set to 0.

    A change to the default values is not recommended without good reason. One obvious change would be to put very large numbers in the threshold files. Large numbers in that file would disable the mechanism, such that to "freeze" a tape or "down" a drive should never occur.

    Freezing and downing are primarily intended to benefit backups. If read errors occur on a restore, a freeze of media has little effect. NetBackup still accesses the tape to perform the restore. In the restore case, downing a bad drive may help.

For further tuning information on tape backup, see the following topics:

See About the threshold for media errors.