backups fill up the root volume

[ms-pve]

Hi everyone,

due to the default setup the root volume can become filled with backups and the whole system halts. What would be the best way to prevent this? Is it possible to reserve space for the root vol but not it's subvolumes?

 

[Dunuin]

First, are you storing your backups on the same drives as your VMs?
Are you using ZFS?

If your first answer is no and your second answer is yes you could create a new dataset on your root pool and use it as a storage for backups. Then you can set a quota (for example zfs set quota=100G rpool/backups) to limit the space that dataset is able to use.

 

[ms-pve]

NAME USED AVAIL REFER MOUNTPOINT
rpool 215G 683G 208K /rpool
rpool/ROOT 97.1G 683G 192K /rpool/ROOT
rpool/ROOT/pve-1 97.1G 683G 97.1G /
rpool/data 117G 683G 192K /rpool/data
rpool/data/vm-100-disk-0 4.26G 683G 4.26G -
rpool/data/vm-101-disk-0 24.0G 683G 24.0G -

I'm using the default setup. My first idea was a separate dataset for backups too, but then setting a refreservation on the ROOT - so no matter if vms or backups become too big, the system should remain responsive. Does this make sense?

 

[Dunuin]

NAME USED AVAIL REFER MOUNTPOINT
rpool 215G 683G 208K /rpool
rpool/ROOT 97.1G 683G 192K /rpool/ROOT
rpool/ROOT/pve-1 97.1G 683G 97.1G /
rpool/data 117G 683G 192K /rpool/data
rpool/data/vm-100-disk-0 4.26G 683G 4.26G -
rpool/data/vm-101-disk-0 24.0G 683G 24.0G -

I'm using the default setup. My first idea was a separate dataset for backups too, but then setting a refreservation on the ROOT - so no matter if vms or backups become too big, the system should remain responsive. Does this make sense?

It makes no sense if you are storing the backups on the same pool your VMs are running on. If the pool gets degrades you will loose the VMs and your backups (so everything).

You should by another hdd and create a separate pool to store your backups or better get a NAS and mount a SMB/NFS share as your backup storage.

 

[ms-pve]

absolutely, this is just the local copy, I am using a NAS for backups.
But you're right - if I keep them on the NAS and would set a refreservation on the ROOT vol the issue should be resolved.

 

[hepo]

then you should mount (Datacenter --> Storage) the NAS via NFS/CIFS and do backup directly on the NAS

Your other option is to set the backup retention (e.g. keep last 2) on your root volume, but this would be still lame