[PVE-User] Analysis of free space...

[Marco Gaiarin]

> Uh, wait... effectively we forgot to enable 'discard' on volumes, and we have
> enabled afterward (but rebooted the VM).

Still here. I've rechecked every passage and i summarize here:

1) ZFS storage had 'Thin provision' enabled from the start

2) we create a bounch of volumes for the VM, and, using LVM, bind that on some
 logical volumes XFS formatted. 'discard' was not checked.

3) we delete roughly 20+TB of data from VM, we try to copy some more data on
 VM volumes but storage fill up.

4) we enabled 'discard' on volumes, reboot VM and phisical node, do some
 manual trim: some TB get freed, but not 20+TB.

5) we find another 8TB of junk data and delete them; after that, we do a
 manual trim that freed 8TB on storage.


Evidently data copied (and deleted) on voluems before we set 'discard=on'
are not managed by trim, and we need in some way to force some FS
'rescan'...


How? Thanks.

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