[pve-devel] [PATCH pve-storage] lvm: use blkdiscard instead cstream to saferemove drive

[Wolfgang Bumiller]

On Thu, Aug 14, 2025 at 10:07:59AM +0000, DERUMIER, Alexandre wrote:
> > +        saferemove_discard => {
> > +            description => "Wipe with discard instead zeroing.",
> > +            type => 'boolean',
> 
> >>Not sure we need this (not sure when this is actually useful), but
> >>it's
> >>cheap enough to have around. Should add a `default => 0` for
> >>documentation purposes, though.
> 
> Some storage allow overprovisioning. (create a lun bigger than the real
> storage size), it can be interesting to discard instead zeroing (to
> free space on storage side).
> as snapshots currently use lvm volume with same size than the main
> volume, it can be interesting to have overprovisioning.

But this does not guarantee that the data is actually erased/zeroed, in
which case I'd just disable the thing altogether (but then again I use
`issue_discards` in lvm.conf to cause `lvremove` to discard the whole
thing... ;-)