Two backup programs, diff and log out of sync I am running encrypted backup on SQL Server 2017.
Doing a test restore, it failed:
RESTORE DATABASE [test] 
FROM DISK = N'\\DPH-DD-SLI-001\SLI_SQL_Backups\Encrypted\DPH-SQL-SLI-12P\BTBLEAD\FULL\DPH-SQL-SLI-12P_BTBLEAD_FULL_20201021_185145.bak' 
WITH NORECOVERY, REPLACE; 

RESTORE DATABASE [test] 
FROM DISK = N'\\DPH-DD-SLI-001\SLI_SQL_Backups\Encrypted\DPH-SQL-SLI-12P\BTBLEAD\DIFF\DPH-SQL-SLI-12P_BTBLEAD_DIFF_20201022_071002.bak' 
WITH NORECOVERY; 

Processed 199264 pages for database 'test', file 'BTBLEAD_Data' on file 1.
Processed 2 pages for database 'test', file 'BTBLEAD_Log' on file 1.
RESTORE DATABASE successfully processed 199266 pages in 446.348 seconds (3.487 MB/sec).
Msg 3136, Level 16, State 1, Line 6 This differential backup cannot be restored
because the database has not been restored to the correct earlier state.
Msg 3013, Level 16, State 1, Line 6 RESTORE DATABASE is terminating abnormally.

It WAS running flawlessly, until they installed Commvault cloud backup.
I found that if a Commvault backup kicks off, I can no longer restore my native local backup past the point in time that Commvault kicked off!
Apparently, SQL Server resets the LSN on each backup, but doesn't know there are two distinct programs running.  When Commvault kicks off, the LSN is brought forward, and my native backup does not know about it
I like having my own local backup, as it is faster and quicker to restore than the cloud backup, than waiting for another group to do the restore from the cloud for me.
Is there any way to keep the backups separated?
Another group manages the Commvault backup. I am new to SQL Server - I am an Oracle DBA by trade.
Differential backups are attached to the Full. If your other backup tool takes a full, it's normal that you cannot restore your diff without that full.
You should not use 2 different backup tool in parallel. If you really need to, then you can check if it's possible to specify the &quot;copy_only&quot; option for the backup in CommVault (so your native backup will remains the &quot;official&quot; backups).
If it's not possible, you could then do only full (with copy only) on your side. Of course, if the database are big, this mean bigger backup and longer time to restore.
Maybe you should address the problem at the source. It seems to me that what you really need is permission in CommVault to be able to run restore from that tool.