Help with LVM thin

[Jokerigno]

Hi,
I have a mini pc (NUC like) running proxmox 7.4-16 with 2 VM on it: Home Assistant and Nextcloud Pi.
I'm running some critical storage issue and can't find a way to fix it. Basically VMs becomes unavailabe and I temporary solved by adding space to VMs (following a suggestion received).
After few days LVM becomes once again full 100% and VM are again unresponsive.
any mid term solution?

This is my lvs output:

root@JARVIS:~# lvs
LV            VG  Attr       LSize    Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
data          pve twi-aotzD- <144.53g             100.00 4.34
root          pve -wi-ao----  <70.50g
swap          pve -wi-ao----    4.00g
vm-100-disk-0 pve Vwi-aotz--    4.00m data        0.00
vm-100-disk-1 pve Vwi-aotz--  156.00g data        28.91
vm-102-disk-0 pve Vwi-a-tz--  110.00g data        90.38

 

[gurubert]

You have provisioned more storage to the VMs (156G + 110G = 266G) than is available in the pool data (144G). The VMs do not know anything about this limitation and will happily try to write more data to their disks than fit in the pool.

 

[Jokerigno]

You have provisioned more storage to the VMs (156G + 110G = 266G) than is available in the pool data (144G). The VMs do not know anything about this limitation and will happily try to write more data to their disks than fit in the pool.

Ok and there’s a way to fix it without starting from scratch again?

 

[gurubert]

You could try to reduce the used size of the virtual disks by resizing the filesystems inside the VMs.

 

[Jokerigno]

ok. I think i'll ask support in the VMs forum (Nextcloud and home Assistant). But then when the space is free how can I reduce in Proxmox the space allocated (ex: from 156G to 100G)?

 

[abufrejoval]

Reducing file systems AFAIK is rarely supported on Linux nor shrinking disks on hypervisors. But I believe you can effectively reclaim the space by trimming inside the VM if discard is enabled on the disk. The logical allocation will remain at 156GB and the inherent danger of overcommit will remain, but at least you'll have your system back.