10-11-2016 04:13 AM
What are peoples experience with SQL log behaviour, when doing a Hyper-V backup of a SQL server with databases in full mode ?
Have already looked at the theoretical stuff which seems to be conflicting as the Hyper-V VSS system is supposed to send a log truncate at successful backup and the SQL writer which does not seems to support log truncate.
10-11-2016 05:39 AM
To my knowledge, only NBU for VMware supports 'Application aware' backups.
For Applications and DBs on Hyper-V, regular agent backups should be performed.
10-11-2016 06:17 AM
Yes, I know that is the Veritas stand point. But I am as written interested in peoples real life experiences as the theoretical stuff is conflicting.
My personal suspicion is that the Hyper-V VSS sends the truncate log and that the SQL writer discards it as this writer does not support the log truncate.
10-11-2016 06:29 AM
Hello,
I am not sure I understand this question. Maybe Hyper-V/MS SQL forum is better for this discussion.
However I doubt that Hyper-V VM level snapshot will take care of MS SQL log truncations..
Regards
Michal
10-13-2016 12:32 PM
So far our testing show the SQL logs are not truncated, at least not with the default settings.
10-14-2016 12:38 AM
Hello,
yes , I think it would be "pretty" bug when Hyper-V snapshots (or any non-SQL snapshots) would truncate SQL transaction logs, thus compromising databases recoverability.
Michal