Re: [PATCH qemu-server v2 3/7] api: clone disk: downgrade failure to register unused volume to warning

["Elias Huhsovitz" <e.huhsovitz@proxmox.com>]

I like the approach. I was also considering to simply check the number of
slots used before the actual cloning of the disk, but then we might just
encounter a new edge case down the line... So IMO this solution is
better :D

Reviewed-by: Elias Huhsovitz <e.huhsovitz@proxmox.com>

On Thu Oct 29, 2026 at 1:06 PM CET, Fiona Ebner wrote:
> When reaching the call to register the source volume as unused after
> clone, a running VM will already be switched over to the new disk. If
> an error occurs there (because all unused slots are already in use),
> the new disk would be removed in the error handling. Even if it is an
> offline clone, the failure to register the source volume as unused
> should not lead to aborting/reversing the whole operation. Downgrade
> the error to a warning.
>
> Reported-by: Elias Huhsovitz <e.huhsovitz@proxmox.com>
> Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
> ---
>
> New in v2.
>
>  src/PVE/API2/Qemu.pm | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/src/PVE/API2/Qemu.pm b/src/PVE/API2/Qemu.pm
> index ebbfcb1b..9540db86 100644
> --- a/src/PVE/API2/Qemu.pm
> +++ b/src/PVE/API2/Qemu.pm
> @@ -5012,8 +5012,12 @@ __PACKAGE__->register_method({
>                  $conf->{$disk} = PVE::QemuServer::print_drive($newdrive);
>  
>                  if (!$param->{delete}) {
> -                    my $unused_key = PVE::QemuConfig->add_unused_volume($conf, $old_volid);
> -                    print("adding source volume '$old_volid' as '$unused_key' to config\n");
> +                    eval {
> +                        my $unused_key = PVE::QemuConfig->add_unused_volume($conf, $old_volid);
> +                        print("adding source volume '$old_volid' as '$unused_key' to config\n");
> +                    };
> +                    log_warn("cannot add source volume '$old_volid' as unused to config - $@")
> +                        if $@;
>                  }
>  
>                  # convert moved disk to base if part of template