[Samba] Keeping idmap in sync cross DC

[Rowland Penny]

On Thu, 23 Nov 2017 14:01:03 +0200
Ian Coetzee via samba <samba at lists.samba.org> wrote:

> On 22 November 2017 at 17:45, Rowland Penny <rpenny at samba.org> wrote:
> 
> > On Wed, 22 Nov 2017 16:01:17 +0200
> > Ian Coetzee via samba <samba at lists.samba.org> wrote:
> >
> > > Hi Guys,
> > >
> > > I have run into a very interesting problem using GPO's on our
> > > DC's.
> > >
> > > As you may (or may not) know, we have migrated to a pure Samba4
> > > (Git stable branch checkout) AD network. I can't be happier.
> > > *Kudos to the Samba team*
> > >
> > > We are running to DC's, DC1 and DC2, both full fledged DC's, both
> > > running CentOS 6.9, fully up to date.
> > >
> > > For the sysvol partition I decided to run a glusterfs between the
> > > DC's. I started out with a unison sync, but being the impatient
> > > person I am, I needed more real time.
> > >
> > > Now my problem is with the permissions in the sysvol folder
> > > structure.
> > >
> >
> > Sorry, but your problem is that you missed this:
> >
> > https://wiki.samba.org/index.php/Bidirectional_Rsync/osync_
> > based_SysVol_replication_workaround#FAQ
> >
> > Where it quite clearly says this:
> >
> >      Why can't I simply use a distributed filesystem like GlusterFS,
> > Lustre, etc. for SysVol?
> >         A cluster file system with Samba requires CTDB to be able
> > to do it safely. And CTDB and AD DC are incompatible.
> >
> > Rowland
> >
> 
> Hi Rowland,
> 
> Yes, you are right, I completely missed that part.
> 
> I actually had the system set up using
> https://wiki.samba.org/index.php/Bidirectional_Rsync/Unison_based_SysVol_replication_workaround
> 
> But then I decided to become creative with a glusterfs setup.
> 
> I now have a Osync set up (much easier IMO), but the permissions are
> still not quite right, bringing me back to my idmap syncing question.
> 
> Kind regards

There are instructions here:

https://wiki.samba.org/index.php/Joining_a_Samba_DC_to_an_Existing_Active_Directory#Built-in_Groups_GID_Mappings

Rowland