Q&A: Can I use UCS for TimeMachine Backups from MACs?


Can I use UCS shares as TimeMachine backup target from MACos machines?


Up to Samba version 4.8 there was a bug 3 regarding TimeMachine backups.
With UCS version 4.4 we ship Samba version 4.10 where the bug should have been fixed and therefor could be used as TimeMachine target.
Up to UCS version 4.3-3 Univention does not ship Samba 4.8 (latest is Samba 4.7.8) so UCS prior 4.4 can not be used out-of-the box as TimeMachine target.

SURFsara team tested this solution and found out that it works, but they proposed to edit the following usefull setting:

In /etc/samba/smb.conf the following lines need to be added (via a package, but they have changed template file /etc/univention/templates/files/etc/samba/smb.conf.d/10global to temporally test it ):

print ‘[TimeMachine]’

print ‘\tvfs objects = catia fruit streams_xattr’

print ‘\tfruit:time machine = yes’

print ‘\tfruit:aapl = yes’

Now ucr commit needs to be run.

On the share that has been made, the following parameters need to be added (via the webgui at advanced settings > samba options or at /etc/samba/shares.conf.d/):

fruit:time machine = yes

fruit:advertise_fullsync = true

fruit:nf_aces = no

fruit:resource = file

fruit:metadata = netatalk

fruit:locking = none

fruit:encoding = native

fruit:appl = true

ea support = yes

and vfs_objects need to be changed to vfs objects = catia fruit streams_xattr
After this Time Machine can be mounted and backed-up to the Share.

Surfsara team also found via https://www.spinics.net/lists/samba/msg156952.html that setting the parameter fruit:time machine max size = will break samba and result in [352279.228529] traps: smbd[46647] trap divide error ip:7ffb30813930 sp:7ffefa676d50 error:0 errors in /var/log/syslog and result in samba not working properly.
Setting a qouta at the webgui also works, so the parameter is not needed.

Note: There is a workaround (German) available to use a Samba share as backup target.