[pve-devel] applied: [PATCH container] backup: warn that tar does not honor exclusion pattern with a trailing slash

[Thomas Lamprecht]

Am 31/05/2024 um 12:07 schrieb Fiona Ebner:
> As reported in the community forum [0], for tar, an exclusion pattern
> with a trailing slash will not match a folder with that name. For
> rsync and proxmox-backup-client however, such a pattern will exclude
> a directory with that name, but not a file.
> 
> rsync is used for 'suspend' mode backup and tar is used for all
> non-PBS backups to create the archive. So currently, in the presence
> of an exclusion pattern with a trailing slash, there is inconsistency
> between different backup modes (because for 'suspend' mode, rsync will
> already do the exclusion too) as well as between PBS and non-PBS
> backups.
> 
> There doesn't seem to be a straight-forward way to align the behavior
> for tar with command-line options exactly. The trailing slash can't be
> removed from the pattern, because that would also match files.
> Matching with
>> some/pattern/*
>> some/pattern/.*
> rather than
>> some/pattern/
> gets pretty close, which was suggested by Dominik. Just the empty
> directory is still included.
> 
> In any case, modifying current behavior would be a breaking change, so
> actually aligning the exclusion (more closely) is better done in the
> next major release.
> 
> Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
> ---
> 
> One could argue such a change is a bug-fix and so does not need to
> wait until the next major release. I opted for the safer variant for
> now, but happy to go with the aligning already if that is preferred.

a major release may indeed better for conveying such a change and it
seems not _that_ frequent, so fine by me to wait.

> 
>  src/PVE/VZDump/LXC.pm | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
>

applied, thanks!