> DERUMIER, Alexandre <alexandre.derum...@groupe-cyllene.com> hat am 19.05.2025
> 15:01 CEST geschrieben:
>
>
> > + #if first snapshot,as it should be bigger, we merge child, and
> > rename the snapshot to child
> > + if(!$parentsnap) {
> > + print "commit: merge content of $childpath into $snappath\n";
> > + $cmd = ['/usr/bin/qemu-img', 'commit', $childpath];
> > + eval { run_command($cmd) };
> > + if ($@) {
>
> >>should we add an error here about what state this leaves the snapshot
> >>in?
> >>AFAIU we've potentially written some of the data from $child to
> >>$snap, so
> >>the state of $snap is technically invalid now?
>
> yes, if you try to clone or rollback it, the content is invalid.
> the current is still working, so impact to run the vm, but the
> user really need to delete the snapshot later.
>
> (I'm not sure if you should have some kind of snapshot state in vm
> config, to avoid to call rollback,clone if state is invalid? as the vm
> is locked anyway, maybe some logs is enough ?)
I think we'd at least want to document the expected failure state(s) here,
either as a comment or as a warning..
e.g., we could have a comment detailing what's what (for all the cases), and
a log message recommending deletion of the snapshot that is now "invalid"
(for this particular branch here).
>
> > + $cmd = ['/usr/bin/qemu-img', 'rebase', '-b', $parentpath, '-F',
> > 'qcow2', '-f', 'qcow2', $childpath];
> > + eval { run_command($cmd) };
> > + if ($@) {
> > + die "error rebase $childpath from $parentpath; $@\n";
>
> >>same here, but in this case $child just contains some duplicate data
> >>so nothing is
> >>really broken?
>
> yes, no problem here.
>
>
>
> > + }
> > + #delete the snapshot
> > + eval { $class->free_image($storeid, $scfg, $snap_volname, 0);
> > };
> > + if ($@) {
>
> >>and here we just leave a stray volume around that is not part of the
> >>backing chain
> >>anymore, right?
>
> yes, the end of rebase is switching the backing_file info in the qcow2
> metadatas.
_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
