VM Backups - Snapshot Option

[alasdairc]

Hi all,

I have a question regarding the 'Snapshot' option when it comes to backups. I am looking for a quicker option for less downtime and have been using the Snapshot backup option. I am aware the Snapshot option has more chance for inaccuracies and may cause problems with disk integrity - I may mix a Snapshot option with the Stop backup option schedule

My main question is, lets say my server caught fire and the server host was completely lost. With my Snapshot backups being stored elsewhere, if I rebuild Proxmox, can these VM Snapshot Backups be fully restored?

My backups are currently configured as:

Compression: ZSTD (fast and good)
Mode: Snapshot


Thanks in advance,
Alasdair

 

[Dunuin]

As far as I understand restoring a snapshot backup is like booting a VM that has crashed. KVM will tell the guest to finish async writes (freeze) and then snapshot the virtual disks. Whats not backuped is the RAM and the state of all running programs. For the programs it looks after restoring like a reboot after a power outage. As long as the software is well programmed it can handle that without too much problems and only the latest data will be lost.
But a "stop" mode backup would be way better because everything is shutdown correctly first so nothing is in a undefined state.

I would really like to see backups being able to dump the RAM like the ZFS snapshots with enabled state storage where it is possible to rollback into a running VM without loosing anything.

 

[alasdairc]

Thank you for clarifying that.

I think I will look at using the Snapshot backups for non-critical systems and then full 'Stop' backups for critical systems.

Another side question; I assume the Stop shutdown is a graceful shutdown?


Thanks again

 

[Dunuin]

Another side question; I assume the Stop shutdown is a graceful shutdown?

yes

 

[alasdairc]

yes

Coolio! Thank you!