Does CommVault Support backing up SQL Server Express databases on a client server?

Hi @COE-GT 

We certainly do, you can refer to: https://documentation.commvault.com/commvault/v11/article?p=3002_3.htm which highights the versions of SQL we support (as of feature release 20).

I’d suggest ensuring that auto-close is disabled however otherwise you may encounter failures when we attempt to backup the databases.

Refer to: https://docs.microsoft.com/en-us/sql/relational-databases/policy-based-management/set-the-auto-close-database-option-to-off?view=sql-server-ver15

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​​​​​​​Hopefully this helps.