Question about "Windows VSS enabled" EC2 AWS backups and MS SQL transaction log truncate

Question

Hi,

if I perform an EC2 backup with Windows VSS enabled (i.e. with VSS Agent installed), why is there no log truncate? I can see that the log files keep growing despite the successful application action consistent backup. An SQL query also shows me that a full backup is “not performed in copy only mode”.

Am I making a mistake, is there something else that needs to be configured or is this not possible at all?

regards

Jan

SHAJAM · Answer

You can check if the backup is copy-only by running.
```
SELECT name, is_copy_only FROM msdb.dbo.backupset ORDER BY backup_finish_date DESC;
```
If` is_copy_only = 1`, then VSS is performing a copy-only backup, which does not truncate logs. Note, copy-only backup does not truncate logs. You can take a full backup `BACKUP LOG [YourDatabase] TO DISK = 'NUL';`.

jotge · Answer

Hello SHAJAM,

thank you for your reply.

I realize that a copy-only backup does not perform a log truncate, so I had already tested with another SQL statement of the status of the backup and made sure that it is not a copy-only backup.

Here is the result of my script:
![Enter image description here](/media/postImages/original/IMtITbAARXRuyLa9_ieAR8-w)

That's why I'm wondering about the check of the log file sizes and their fill level which I query with the following script.

`DBCC SQLPERF(LOGSPACE);
GO`

![Enter image description here](/media/postImages/original/IMyL0DF6G8QIyu9YwtvAsOKw)

But I take it from your answer that the AWS EC2 backup with Windows VSS enabled should actually perform a log truncate under normal circumstances. So now I have to look for the reason why this is not happening.

Have a nice day

Question about "Windows VSS enabled" EC2 AWS backups and MS SQL transaction log truncate

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