[Samba] Upgrade Samba versions on the domain

[Andrew Bartlett]

On Tue, 2019-10-29 at 22:41 +0100, Norbert Hanke via samba wrote:
> On 29.10.2019 22:16, Mircea Husz via samba wrote:
> > > On Tuesday, October 29, 2019, 03:41:35 PM CDT, Andrew Bartlett
> > > via samba <samba at lists.samba.org> wrote:
> > > > On Tue, 2019-10-29 at 19:23 +0000, Mircea Husz via samba wrote:
> > > > We're adding a new datacenter and am taking the opportunity to
> > > > upgrade Samba version to 4.11. We have three AD servers
> > > > currently on
> > > > version 4.7.9.
> > > > I plan to add a new AD DC, version 4.11, by joining it to the
> > > > domain.
> > > > Can the domain function in production with three DCs on 4.7.9,
> > > > and a
> > > > new one running 4.11 ?
> > > > Thanks,-Mike
> > > 
> > > Yes, that should be fine.
> > > 
> > > Andrew Bartlett
> > > 
> > 
> > Can DCs be upgraded forklift-style, as in shutting down the VMs and
> > bringing
> > up new VMs in their place, with the same name and address?
> > Obviously counting
> > on DC replication, which has worked without issues so far.
> > 
> > 
> 
> If you demote the old DC before shutting down, and then freshly join
> the
> new one: yes that works.

I would start that new DC in the new datacenter first, before you start
demoting.  That way if there are any issues you know while you still
have a full set of DCs running.

Also, modern Samba versions have backup tools, they are a good thing
and running a remote backup first simulates most of a domain join so
finds issues before anything destructive happens.

Andrew Bartlett
-- 
Andrew Bartlett
https://samba.org/~abartlet/
Authentication Developer, Samba Team         https://samba.org
Samba Development and Support, Catalyst IT   
https://catalyst.net.nz/services/samba