@Ajal 

Truncation occurs essentially the same as with a standalone SQL server. However, with AG transaction log backup will occur on the preferred replica for backup which is most cases is the secondary replia.

Logs are truncated and MSSQL handles updating the copy on primary node.

No action is needed, or backup option needed as long as database is in full recovery model and transaction log backup type is ran.

This doc explains where the backup will run and details:

https://documentation.commvault.com/2022e/expert/18295_always_on_mssql_availability_groups.html#backups-on-availability-group-client

Can truncation be turned off on  SQL? If so how?

Hello @Commvault387 

No there is no way within MSSQL or CVLT or any backup application to perform a transaction log backup and not truncate the log.

Scott

Hi Scott and Thanks for your quick reply.

Okay, because a DB has requested that the CommVault  backup not truncate the transaction log.  They have a log shipping job that runs every 15 minutes that is doing that now.

• Transaction logs are truncated every time a checkpoint is processed. At checkpoint, data and logs are in a consistent state.
• Transaction log is not truncated if you select the Do Not Truncate Log check box.
• Full and differential backups do not truncate the transaction logs.

Thanks Ajal,

Yes, I see that however after I Select the box and click ok and go back in to check it. The selection is blank again. How do you get it to say permanently for the scheduled hourly transaction log backups?

Also is there anyway to check and make sure the backups are not being truncated?

Thanks for you reply

create a schedule and try it , i think you are running manual backup 

Thanks Ajal,

I have done that, now I need to STOP the formerly scheduled SQL Transaction LOG backup from taking place every hour. That can be stopped correct?

if your db team is taking care of transcation log , do only db full job once in a day, 
if you need a transcation log schedule hourly you can use these option , instead of daily use continuous and choose 60 minute also you can create it as subtask in the same schedule 

Thank You ajal,

I will have to check on doing the full job once a day.  I believe they they just do not want CommVault to truncate the transaction backup log hourly.  I am setting up the new schedules now.

Thanks for the help!

The new Transaction NO Truncate backup logs seem to be working.  However, I am getting 

Failed to Start for the old scheduled transaction log backups how do I stop/disable the old scheduled transaction log backup?