Subclients for Lustre (File System)

Subclients contain information about what data is backed up. Lustre (File System) supports the following types of subclients:

  • Default subclients
  • User-defined subclients

When you create an instance, a default subclient is automatically created. You can configure only one Lustre volume for a subclient. To protect different groups of data, you can create user-defined subclients.

You can change the data access nodes that are associated with the default subclient and with the user-defined subclients.

Scan Integration with Meta Data Target (MDT) and Changelog Server

Lustre scan performance is improved by integrating with changelogs retrieved from the MDT Lustre file component.

Commvault software runs the scan operation on the Lustre clients. You must register the changelog users on the MDT so that the changelog user ID can be used to query the MDT. For more information about registering changelog users, go to Lustre Software Release 2.x - Operations Manual, Working with Changelogs.

A changelog reader per subclient is registered on the MDT during the first full backup. Incremental scans retrieve changelogs from the MDTs by using the changelog reader registered to get modified items.


  • Set the changelog mask to HSM CREAT UNLNK TRUNC SATTR CTIME MTIME CLOSE RENME RNMTO RMDIR HLINK LYOUT on the MDT. To prevent data backup failures, do not change the mask between backup jobs.
  • Run a full scan operation, if you change the mount point.

Synchronizing Data on the Disk and the Index for Lustre (File System)

Synchronizing data on the disk and the index operation uses the recursive scan method and might take longer to complete.

Last modified: 9/4/2020 11:07:32 AM