[SOLVED] LVM free space different than real usage

[impassenet]

Hello,

I have a LVM-Thin only for backup and when you check in the node / LVM-thin I can see only ~25 Gb free



Directly in storage it is only ~30% used



On command line using df -h:

/dev/mapper/prod0-backups 492G 145G 322G 31% /proxmox/backups

Using lvs -a:
backup prod0 twi-aotz-- 500.00g 95.30% (used)

Can someone explain me why the LVM-thin seems to be full? And how it is possible to clean it?

I am monitoring the LVM-thin space and receive a lot of alertes, could it be just false positive?

Regards,

 

[sg90]

This looks to me like you have created a LVM thin pool, then created a LVM of nearly the full size and mounted this as a filesystem on the VM. If you have wrote up to around the 500GB at some point unless the FS is passing through trim/discard commands the LVM layer wont remove old data untill its required to overwrite the data.

Try running fstrim /proxmox/backups

 

[impassenet]

Thanks sg90 !
fstrim -v /proxmox/backups

 

[impassenet]

This looks to me like you have created a LVM thin pool, then created a LVM of nearly the full size and mounted this as a filesystem on the VM. If you have wrote up to around the 500GB at some point unless the FS is passing through trim/discard commands the LVM layer wont remove old data untill its required to overwrite the data.

Try running fstrim /proxmox/backups

Thanks i found one thread in the forum speaking about that. Thanks !!