Backup of VM with snapshot seems having some problems

albgen

Member
Jan 9, 2021
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Dears hello,

I just wanted to move some VMs from one Proxmox installation to another.
Usually when i have to do this kind of operation, i stop the vm, start a scp copy of the disk and the config file and all works perfectly.

This time wanted to change and use the backup functionality, basically this one:
1692974035557.png

The problem i noticed after taking the backup with mode "Snapshot", is that once restored, the windows server machine show the window that it did not shutdown properly. Tried with 3 different VMs and same behaviour.

Can be this considered normal behavior? Should i be worried about this?

Thank you,
E.
 
With snapshot-mode you backup the VM in a running state without the state of the RAM. So when restoring it all data in RAM will be lost, all services will kind of crash, like you would have done a hard reset. And without the QEMU guest agent running all cached async writes would be lost too so in that case a non-consistant backup.

So would be better to do a stop-mode backup when you are planning to do a restore.
 
i thought the snapshot mode was also backing up the RAM. It would be better to remove at all this mode or there are use cases when it's useful?
 
Stop-mode will shutdown your VM before doing a backup. So would be terrible without snapshot-mode if you care about uptime. Think of a hourly backup job that will shutdown your VM every hour so it's each hour not available for some minutes...