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Best practice for NetBackup catalog layout

Article: 100003918
Last Published: 2023-03-02
Ratings: 3 2
Product(s): NetBackup & Alta Data Protection

Problem

This document presents some suggestions on how the databases can be relocated to separate file systems to reduce I/O contention and improve performance.  The layouts presented in this document offer the best combinations for most environments. However it is possible that for some environments different arrangements of the various files might perform better.

By default the NetBackup binaries and databases are installed to a common path (/usr/openv on UNIX/Linux and install_path\Veritas on Windows) which is typically a single file system.  While this gives acceptable performance for most customer environments it does result in a lot of I/O contention between the database and logging process and can lead to degraded performance, particularly in larger environments where I/O traffic during backup windows is significant. 
 

Solution

Components that may be affected by I/O contention:

The following components should, as much as possible, be located on different disks to minimize contention.  (For the purposes of this document the word ‘disk’ means a file system configured on the storage to avoid I/O contention with other file systems.):
  • The Veritas Unified (VxUL) log files.
  • The catalog flat file components, in particular the image database.
  • The catalog relational database data files.

If running NetBackup 10.1.1 or earlier, these additional components should also be located on different disks:

  • The catalog relational database index files.
  • The catalog relational database transaction logs.

As a general rule the relational database files should be located on RAID 5 or RAID 10 storage to achieve the best mix of performance and resilience.

How to arrange things based on the number of disks available:

Here are some example configurations of how to arrange your files depending on the number of disks you have available. These examples assume NetBackup has been installed into a single path on Disk 1 and identify which components to move to which alternate disks:

  • 2 Disks– Place the catalog flat file components, and the relational database files on disk 2, leave all other components on disk 1:
    • Disk 2 - The flat file components, and the relational database files.
    • Disk 1 - All other components.
  • 3 Disks– Place the catalog flat file components on disk 2, place the relational database data files on disk 3, leave all other components on disk 1:
    • Disk 3 - The relational database files.
    • Disk 2 - The flat file components.
    • Disk 1 - All other components.
  • 4 Disks – Place the catalog flat file components on disk 2, place the relational database data files on disk 3, place the relational database index files and relational database transaction logs on disk 4, leave all other components on disk 1:
    • Disk 4 - Veritas Unified Logging (VxUL) files and other NetBackup log files.
      • If running NetBackup 10.1.1 or earlier, keep the VxUL files on Disk 1, and place the relational database index and transaction log files on Disk 4 instead.
    • Disk 3 - The relational database files.
    • Disk 2 - The flat file components.
    • Disk 1 - All other components.

If running NetBackup 10.1.1 or earlier, the relational database indices and transaction logs can further be separated:

  • 5 Disks – Place the catalog flat file components on disk 2, place the relational database data files on disk 3, place relational database index files and relational database transaction logs on disk 4, place the unified logs on disk 5, leave all other components on disk 1:
    • Disk 5 - Veritas Unified Logging (VxUL) files and other NetBackup log files.
    • Disk 4 - The relational database index and transaction log files.
    • Disk 3 - The relational database data files.
    • Disk 2 - The flat file components.
    • Disk 1 - All other components.
  • 6 Disks – Place the catalog flat file components on disk 2, place the relational database data files on disk 3, place the relational database index files on disk 4, place the unified logs on disk 5, place the relational database transaction logs on disk 6, leave all other components on disk 1.
    • Disk 6 - The relational database transaction log files.
    • Disk 5 - Veritas Unified Logging (VxUL) files and other NetBackup log files.
    • Disk 4 - The relational database index files.
    • Disk 3 - The relational database data files.
    • Disk 2 - The flat file components.
    • Disk 1 - All other components.

Relocating flat file components:

The flat file components reside under /usr/openv/netbackup/db on Unix & Linux and install_path\Veritas\NetBackup\db on Windows.

There are no commands to move the image database but it is possible to use soft links (created using the mklink command on Windows and ln -s on Unix and Linux) to create links to a separate file system. The catalog backup will follow these links.

The largest and most I/O intensive part of the flat file components is the image database (/usr/openv/netbackup/db/images on Unix and Linux and install_path\Veritas\NetBackup\db\images on Windows) and you can also link at this level to just relocate the image database.

For earlier versions of Windows where there is no link command the image database can still be relocated to a separate file systems by using ALTPATH entries at the client level (i.e. each client directory, install_path\Veritas\NetBackup\db\images\<client_name> must contain a file called ALTPATH which includes the path to the corresponding client directory on the alternative disk. Details of how to move catalog image trees and use the ALTPATH feature can be found in the section headed "Moving the image catalog" in NetBackup Administrator's Guide, Volume I.

Relocating relational database components:

Use the nbdb_move command to relocate the different components of the relational databases, the -data qualifier determines the location of the data files. 

For NetBackup 10.1.1 or earlier, additionally the -index qualifier can be use to determine the location of the index files and the -tlog qualifier can be used to determine the location of the transaction logs.

Example:

/usr/openv/db/bin/nbdb_move -data /netbackupdb/data

install_path\Veritas\NetBackup\bin\nbdb_move -data N:\netbackupdb

Pre 10.1.1 example:

/usr/openv/db/bin/nbdb_move -data /netbackupdb/data -index /netbackupdb/index -tlog /netbackupdb/logs

install_path\Veritas\NetBackup\bin\nbdb_move -data N:\netbackupdbdata -index M:\netbackupdbindex -tlog O:\netbackupdblog

In this example there may be a single disk/mount point of /netbackupdb or separate mount points for each component.

Relocating log files:

The default location for the most of the NetBackup log files, sometimes referred to as the "legacy logs" is /usr/openv/netbackup/logs on Unix and Linux and install_path\Veritas\NetBackup\logs on Windows.

The default location for NetBackup's Unified log files is /usr/openv/logs on Unix and Linux and install_path\Veritas\NetBackup\logs on Windows. 

On Windows the VxUL logging directories are co-located in the same directory as the other NetBackup log files, install_path\Veritas\NetBackup\logs.  

The Unified logging can be configured to log files to an alternate location using the vxlogcfg command, specify the new path to the log files using "-s LogDirectory <new_log_path>".

For Unix/Linux the syntax is:
/usr/openv/netbackup/bin/vxlogcfg -a -p NB -o Default -s LogDirectory=new_log_path

For Windows the syntax is:
install_path\NetBackup\bin\vxlogcfg -a -p NB -o Default -s LogDirectory=new_log_path
 
The NetBackup logs, /usr/openv/netbackup/logs on Unix and Linux and install_path\Veritas\NetBackup\logs on Windows, should be co-located with the Unified log files.  If Unified logs are being moved, additionally soft link the rest of the NetBackup logs to the same disk where Unified logs are being relocated.  The soft links can be made using mklink for Windows and ln -s for Unix and Linux.
 
Relocating the relational database staging area:
 
One final piece of the catalog that can be optional relocated is the staging area used to hold the temporary databases that created at catalog backup time.  By default this area is /usr/openv/db/staging on Unix/Linux machines and install_path\Veritas\NetBackupDB\staging on Windows machines.  Relocating the staging area to a different disk can improve performance during backup and restore. The following command can be used to relocate the staging area.

nbdb_admin -vxdbms_nb_staging new_staging_area

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