[Samba] Samba AD: gidNumber?

[Viktor Trojanovic]

I joined a Samba AD member server (file server) to a Samba AD DC. This 
seems to have worked. However, if I try to access the file server from 
the domain administrator account on a Windows client, I am asked to 
provide authorization details. Since I have no other privileged users, I 
am using the domain admin credentials but they're not accepted.

I'm not sure exactly where to look but I think the problem could be 
connected to the following: On my member server, the getent command does 
not yield any results. As per the recommendations on the "Samba Member 
Server Troubleshooting" page, I checked on the DC if the group Domain 
Users has a gidNumber. Well, it doesn't. Neither do my users have 
uidNumbers though this, allegedly, is not such an issue.

To solve it, all it says is to "add a gidNumber to Domain Users".

How do I do that?