[Samba] trouble with shadow_copy2

[Alexander Harm || ApfelQ]

Hello,

I’m running Samba 4.17.3 on Debian Bullseye installed from backports. The shares are located on btrfs subvolumes and we are trying to map them into Windows’ previous versions using shadow_copy2.

I noticed that at some point it stopped working and we have the following error in the logs:

[2022/11/17 18:27:38.865103, 0] ../../lib/util/modules.c:49(load_module)
Error loading module '/usr/lib/x86_64-linux-gnu/samba/vfs/shadow_copy2.so': /lib/x86_64-linux-gnu/libsmbconf.so.0: version `SMBCONF_0.0.1' not found (required by /usr/lib/x86_64-linux-gnu/samba/vfs/shadow_copy2.so)
[2022/11/17 18:27:38.865133, 0] ../../source3/smbd/vfs.c:185(vfs_init_custom)
error probing vfs module 'shadow_copy2': NT_STATUS_UNSUCCESSFUL
[2022/11/17 18:27:38.865148, 0] ../../source3/smbd/vfs.c:399(smbd_vfs_init)
smbd_vfs_init: vfs_init_custom failed for shadow_copy2
[2022/11/17 18:27:38.865160, 0] ../../source3/smbd/service.c:638(make_connection_snum)
make_connection_snum: vfs_init failed for service MyShare

The share is configured like this:

[MyShare]
create mask = 0664
directory mask = 0775
ea support = No
force create mode = 0664
force directory mode = 0775
hide special files = Yes
inherit acls = Yes
inherit permissions = Yes
path = /srv/data/MyShare/
read only = No
store dos attributes = No
valid users = a b @c
vfs objects = btrfs shadow_copy2
write list = a b @c
shadow:snapdir = .snapshots
shadow:sort = desc
shadow:localtime = no
shadow:format = "S.%Y%m%dT%H%M%S%z”

We use btrbk which creates snapshots like this “S.20221206T104601+0100”.

My Google foo unfortunately fails me. I checked that all installed Samba packages are from backports with the same version.

After I rebooted the server the error seems to have disappeared. However, there is still nothing in previous versions. I also played with shadow:localtime = yes|no but it has no effect.

Has anyone an idea? Highly appreciated.

Alexander