Thank you for your quick feedback. I will fix it in the new patchset v2.
Along with it, I will also send a patchset for pve-manager, which adds support
to the UI as well.

David Riley píše v čt 05. 03. 2026 v 15:52 +0100:
> no deep review I just noted a small thing, comment inline
> 
> On 3/5/26 1:08 PM, mail@romanondracek.cz wrote:
> > From: Roman Ondráček <mail@romanondracek.cz>
> > 
> > Signed-off-by: Roman Ondráček <mail@romanondracek.cz>
> > ---
> >   debian/control                     |  1 +
> >   src/PVE/Storage.pm                 |  5 ++++-
> >   src/PVE/Storage/Plugin.pm          |  2 +-
> >   src/test/archive_info_test.pm      |  6 ++++--
> >   src/test/list_volumes_test.pm      | 11 ++++++++++-
> >   src/test/parse_volname_test.pm     |  8 ++++----
> >   src/test/path_to_volume_id_test.pm | 12 +++++++-----
> >   7 files changed, 31 insertions(+), 14 deletions(-)
> > 
> > diff --git a/debian/control b/debian/control
> > index 6bd55a2..9ef10e6 100644
> > --- a/debian/control
> > +++ b/debian/control
> > @@ -50,6 +50,7 @@ Depends: bzip2,
> >            smbclient,
> >            thin-provisioning-tools,
> >            udev,
> > +         xz-utils,
> >            zstd,
> >            ${misc:Depends},
> >            ${perl:Depends},
> > diff --git a/src/PVE/Storage.pm b/src/PVE/Storage.pm
> > index 6e87bac..b9ae6d7 100755
> > --- a/src/PVE/Storage.pm
> > +++ b/src/PVE/Storage.pm
> > @@ -115,7 +115,7 @@ PVE::Storage::Plugin->init();
> >   
> >   our $ISO_EXT_RE_0 = qr/\.(?:iso|img)/i;
> >   
> > -our $VZTMPL_EXT_RE_1 = qr/\.(?|(tar)(?!\.)|tar\.(gz|xz|zst|bz2))/i;
> > +our $VZTMPL_EXT_RE_1 = qr/\.(?|(tar)(?!\.)|tar\.(gz|xz|zst|bz2|xz))/i;
> seems like xz was already part of the regex.
> >   
> >   our $BACKUP_EXT_RE_2 =
> > qr/\.(tgz|(?:tar|vma)(?:\.(${\PVE::Storage::Plugin::COMPRESSOR_RE}))?)/;
> >   
> > @@ -1761,18 +1761,21 @@ sub decompressor_info {
> >               lzo => ['tar', '--lzop'],
> >               zst => ['tar', '--zstd'],
> >               bz2 => ['tar', '--bzip2'],
> > +            xz => ['tar', '--xz'],
> >           },
> >           vma => {
> >               gz => ['zcat'],
> >               lzo => ['lzop', '-d', '-c'],
> >               zst => ['zstd', '-q', '-d', '-c'],
> >               bz2 => ['bzcat', '-q'],
> > +            xz => ['xz', '-q', '-d', '-c'],
> >           },
> >           iso => {
> >               gz => ['zcat'],
> >               lzo => ['lzop', '-d', '-c'],
> >               zst => ['zstd', '-q', '-d', '-c'],
> >               bz2 => ['bzcat', '-q'],
> > +            xz => ['xz', '-q', '-d', '-c'],
> >           },
> >       };
> >   
> > diff --git a/src/PVE/Storage/Plugin.pm b/src/PVE/Storage/Plugin.pm
> > index 6f3d691..5b0216e 100644
> > --- a/src/PVE/Storage/Plugin.pm
> > +++ b/src/PVE/Storage/Plugin.pm
> > @@ -21,7 +21,7 @@ use JSON;
> >   
> >   use base qw(PVE::SectionConfig);
> >   
> > -use constant KNOWN_COMPRESSION_FORMATS => ('gz', 'lzo', 'zst', 'bz2');
> > +use constant KNOWN_COMPRESSION_FORMATS => ('gz', 'lzo', 'zst', 'bz2',
> > 'xz');
> >   use constant COMPRESSOR_RE => join('|', KNOWN_COMPRESSION_FORMATS);
> >   
> >   use constant LOG_EXT => ".log";
> > diff --git a/src/test/archive_info_test.pm b/src/test/archive_info_test.pm
> > index c5c3992..b8dfbff 100644
> > --- a/src/test/archive_info_test.pm
> > +++ b/src/test/archive_info_test.pm
> > @@ -115,19 +115,21 @@ my $tests = [
> >       },
> >   ];
> >   
> > -# add new compression fromats to test
> > +# add new compression formats to test
> >   my $decompressor = {
> >       tar => {
> >           gz => ['tar', '-z'],
> >           lzo => ['tar', '--lzop'],
> >           zst => ['tar', '--zstd'],
> >           bz2 => ['tar', '--bzip2'],
> > +        xz => ['tar', '--xz'],
> >       },
> >       vma => {
> >           gz => ['zcat'],
> >           lzo => ['lzop', '-d', '-c'],
> >           zst => ['zstd', '-q', '-d', '-c'],
> >           bz2 => ['bzcat', '-q'],
> > +        xz => ['xz', '-q', '-d', '-c'],
> >       },
> >   };
> >   
> > @@ -167,7 +169,7 @@ for my $virt (sort keys %$bkp_suffix) {
> >   my $non_bkp_suffix = {
> >       'openvz' => ['zip', 'tgz.lzo', 'zip.gz', ''],
> >       'lxc' => ['zip', 'tgz.lzo', 'zip.gz', ''],
> > -    'qemu' => ['vma.xz', 'vms.gz', 'vmx.zst', ''],
> > +    'qemu' => ['vms.gz', 'vmx.zst', ''],
> >       'none' => ['tar.gz'],
> >   };
> >   
> > diff --git a/src/test/list_volumes_test.pm b/src/test/list_volumes_test.pm
> > index 0876902..d79e991 100644
> > --- a/src/test/list_volumes_test.pm
> > +++ b/src/test/list_volumes_test.pm
> > @@ -90,6 +90,7 @@ my @tests = (
> >               "$storage_dir/images/16110/vm-16110-disk-1.raw",
> >               "$storage_dir/images/16110/vm-16110-disk-2.vmdk",
> >               "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_11_40.vma.gz",
> > +            "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_12_40.vma.xz",
> >               "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_12_45.vma.lzo",
> >               "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_13_55.vma",
> >               "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_13_55.vma.zst",
> > @@ -136,6 +137,15 @@ my @tests = (
> >                   'vmid' => '16110',
> >                   'volid' => 'local:backup/vzdump-qemu-16110-2020_03_30-
> > 21_11_40.vma.gz',
> >               },
> > +            {
> > +                'content' => 'backup',
> > +                'ctime' => 1585602760,
> > +                'format' => 'vma.xz',
> > +                'size' => DEFAULT_SIZE,
> > +                'subtype' => 'qemu',
> > +                'vmid' => '16110',
> > +                'volid' => 'local:backup/vzdump-qemu-16110-2020_03_30-
> > 21_12_40.vma.xz',
> > +            },
> >               {
> >                   'content' => 'backup',
> >                   'ctime' => 1585602765,
> > @@ -457,7 +467,6 @@ my @tests = (
> >               "$storage_dir/private/subvol-19254-disk-0/19254",
> >               "$storage_dir/dump/vzdump-openvz-16112-2020_03_30-
> > 21_39_30.zip.gz",
> >               "$storage_dir/dump/vzdump-openvz-16112-2020_03_30-
> > 21_39_30.tgz.lzo",
> > -            "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_12_40.vma.xz",
> >               "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_12_40.vms.gz",
> >           ],
> >           expected => [], # returns empty list
> > diff --git a/src/test/parse_volname_test.pm
> > b/src/test/parse_volname_test.pm
> > index 5c9478a..035e3ee 100644
> > --- a/src/test/parse_volname_test.pm
> > +++ b/src/test/parse_volname_test.pm
> > @@ -247,9 +247,9 @@ foreach my $s (@$disk_suffix) {
> >   
> >   # create more test cases for backup files matches
> >   my $bkp_suffix = {
> > -    qemu => ['vma', 'vma.gz', 'vma.lzo', 'vma.zst'],
> > -    lxc => ['tar', 'tgz', 'tar.gz', 'tar.lzo', 'tar.zst', 'tar.bz2'],
> > -    openvz => ['tar', 'tgz', 'tar.gz', 'tar.lzo', 'tar.zst'],
> > +    qemu => ['vma', 'vma.gz', 'vma.lzo', 'vma.xz', 'vma.zst'],
> > +    lxc => ['tar', 'tgz', 'tar.gz', 'tar.lzo', 'tar.xz', 'tar.zst',
> > 'tar.bz2'],
> > +    openvz => ['tar', 'tgz', 'tar.gz', 'tar.lzo', 'tar.xz', 'tar.zst'],
> >   };
> >   
> >   foreach my $virt (keys %$bkp_suffix) {
> > @@ -277,7 +277,7 @@ foreach my $virt (keys %$bkp_suffix) {
> >   
> >   # create more test cases for failed backup files matches
> >   my $non_bkp_suffix = {
> > -    qemu => ['vms.gz', 'vma.xz'],
> > +    qemu => ['vms.gz'],
> >       lxc => ['zip.gz', 'tgz.lzo'],
> >   };
> >   foreach my $virt (keys %$non_bkp_suffix) {
> > diff --git a/src/test/path_to_volume_id_test.pm
> > b/src/test/path_to_volume_id_test.pm
> > index dfa51e6..ad3f39a 100644
> > --- a/src/test/path_to_volume_id_test.pm
> > +++ b/src/test/path_to_volume_id_test.pm
> > @@ -92,6 +92,13 @@ my @tests = (
> >               'backup', 'local:backup/vzdump-lxc-16112-2020_03_30-
> > 21_39_30.tar.lzo',
> >           ],
> >       },
> > +    {
> > +        description => 'Backup, vma.xz',
> > +        volname => "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_12_40.vma.xz",
> > +        expected => [
> > +            'backup', 'local:backup/vzdump-qemu-16110-2020_03_30-
> > 21_12_40.vma.xz',
> > +        ],
> > +    },
> >       {
> >           description => 'Backup, vma.zst',
> >           volname => "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_13_55.vma.zst",
> > @@ -212,11 +219,6 @@ my @tests = (
> >           volname => "$storage_dir/dump/vzdump-openvz-16112-2020_03_30-
> > 21_39_30.tgz.lzo",
> >           expected => [''],
> >       },
> > -    {
> > -        description => 'Backup, wrong ending, qemu, vma.xz',
> > -        volname => "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_12_40.vma.xz",
> > -        expected => [''],
> > -    },
> >       {
> >           description => 'Backup, wrong format, qemu, vms.gz',
> >           volname => "$storage_dir/dump/vzdump-qemu-16110-2020_03_30-
> > 21_12_40.vms.gz",