Does ZFS replication call qemu guest-fsfreeze?


Renowned Member
Mar 14, 2012

does ZFS replication (GUI option) call qemu geust-fsfreeze upon each sync? It seems so to me.
Is it really necessary, as it seems that VMs without qemu agent enabled are replicated just fine?

Yes it does. I suggest to keep guest-fsfreeze in order to have consistent backups.
Mandatory for SQL databases. I use it to backup a ZFS disk for my SQL Server 2016 (every 2 hours). It locks FS only 2 or 3 seconds.

If it's not the point, you could create your own scripts...
Wow, that is a fast reply TwiX. :)

I also do backups with my own scripts (need more history on backup server than on prod.) where I do not lock fs of guest.
Unless database spans across multiple ZFS volumes, snapshots should be atomic and databases as well as journaled fs shoud have no problem.
But I will leave it on, unless it starts to become a real problem (I do 1 minute sync interval). I just investigated where does these guest fs freezes come from.


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