[Samba] group membership inconsistency on AD domain member

Matthias Leopold matthias.leopold at meduniwien.ac.at
Fri Feb 1 17:00:51 UTC 2019


I've been running a samba server with winbind (CentOS 7) as a member of 
an AD Domain (Windows 2012 R2) for several months without a problem. 
"Suddenly" I'm seeing the problem that the membership in newly created 
AD groups isn't correctly visible for some users on the samba server or 
only after some indefinite amount of time. I'm looking simply at the 
output of the 'id' command. This information is always consistent with 
the output of 'wbinfo -r', so I don't think it's a NSS problem. The 
"funny" thing is that this doesn't apply to all of the members of the 
newly created group, only for some of them.

On the DC i checked the affected users with the powershell command 
"get-aduser $username -Properties memberof | select -expand memberof", 
everything is correct.

To my experience the problem goes away after some time (a couple of 
hours) for some users, again not all of them. I fiddled with some 
winbind options in smb.conf, restarted winbind a couple of times, used 
"net cache flush", none of these changed anything. I didn't restart the 
AD or smbd though. Can anybody give me a hint?


Example (i temporarily set "winbind expand groups = 1" to use "getent 
group", but this doesn't affect the problem):

# getent group 'FOOBAR\testgroup'

# wbinfo -r 'FOOBAR\user01' | grep -c 13688

# wbinfo -r 'FOOBAR\user01' | grep -c 13688


         load printers = No
         log file = /var/log/samba/log.smbd
         realm = FOOBAR.DOMAIN.TLD
         security = ADS
         unix extensions = No
         workgroup = FOOBAR
         idmap config foobar : range = 10000-999999
         idmap config foobar : backend = rid
         idmap config * : range = 3000-7999
         idmap config * : backend = tdb
         map acl inherit = Yes
         store dos attributes = Yes
         strict sync = No

         browseable = No
         path = /srv/samba01/lv01/exampleshare
         read only = No
         vfs objects = acl_xattr

More information about the samba mailing list