Frequent Copy-only full backups running on SQL Server VM in Azure

Question

We got a SQL Server VM in Azure with both Azure Server backups and Azure SQL Database backups configured.

Azure SQL Database backups are configured as FULL backups on Sunday and DIFF backups the other 6 days but I noticed there are frequent (7 times a day) copy-only full backups running.

I understand that that as part of Azure SQL Server VM backup, it will trigger a copy-only full backup (and we got VM Backups running at 10:00 pm, so the copy-only full backup at around 10:15 pm is related to this), but not sure what's taking the other 6 copy-only full backups (they run every 4 hours at 1:30 AM, 5:30 AM, 9:30AM, 1:30PM, 5:30PM, 9:30PM). Any ideas where to look for

I have attached a screenshot of backup history for one of the databases on the SQL Server. A normal FULL backup which run on Sunday at 7:00PM takes about 200 mins and DIFF backups which run the other 6 days at 7:00 pm takes about 8-10 mins. The copy-only full backups take only few seconds but when they run, the I/O gets frozen and its impacting the SQL performance during business hours.

I would like to know what could be triggering these copy-only FULL backups so we can disable them. We don't have any other database backup tools (SQL Agent jobs or 3rd party tools like NetBackup, Veaam, CommVault etc.)

Answer 1

@GeethaThatipatri-MSFT We are experiencing similar behavior.
We are aware that Azure VM backup trigger this copy-only full backups.

What I don't understand is why in logs of SQL server these copy-only full backups finish in 5 seconds and regular full backups have times like 5 minutes.

If copy-only full backups are almost identical to full backups, they both need to finish in similar time right?

If so why then these timings in logs are not correct?

Answer 2

Ocorreu isso comigo após um update do KB5029376, depois de muita pesquisa, em meu caso desativei o serviço SQL Server VSS Write solucionando o problema, espero que ajude!