MS SQL AG with a primary, as well as a secondary replica, which replica is used as a source for Commvault backup?

https://documentation.commvault.com/2023e/essential/always_on_availability_groups_for_sql_server.html

You can run the following backups on the primary and secondary replica:

• Full and differential backups: These backups always run on the primary replica.

• Transaction log backups: If the primary replica is set as the preferred replica for running backups, then transaction log backups run on the primary replica. Otherwise, the transaction log backups run on the secondary replica that has the highest backup priority.

Thanks,
Scott

Hi Scott, many thanks for reply.

If Commcell backup is an incremental backup, which AG’s replica will be accessed by Commvault?

is Primary or Secondary replica?

Since incremental backup is much often used in a real BK/DR environment…...

I guess it depends on what you mean when you say “Incremental”.
Depending on if you mean Transaction or Differential, see above doc.
 

Thanks,
Scott
 

Full and diffs are taken from the primary. Tlog (sometimes incorrectly referenced as incremental) backups are following the configuration set at AG level in the SQL server.

Hi Scott and Jacek, thank you so very much!