Disjoining one domain from a CTDB cluster and joining another

[Richard Sharpe]

On Sat, Jan 10, 2015 at 9:24 AM, Michael Adam <obnox at samba.org> wrote:
> Richard,
>
> On 2015-01-10 at 07:09 -0800, Richard Sharpe wrote:
>>
>> When disjoining a domain from a CTDB cluster
>
> Do you rather mean having the cluster leave the Domain?
>
>> do you have to disable CTDB control of winbindd and then
>> re-enable CTDB control of winbindd when you have joined
>> the new domain?
>
> What do you actually mean by "disable CTDB control of winbind"?
>
> 1) If you mean removing "clustering = yes" from smb.conf,
>    then the answer is no. You never do that!
>
> A server is either clustered or not, but it does usually not
> change during its lifetime, and especially not temporarily for
> some administrative tasks!
>
> If you disable clustering in smb.conf, then all of a sudden you
> are faced with a completely different server because it uses
> different databases.
>
>
> 2) If you mean "CTDB_MANAGES_WINBIND=yes/no", then the answer
>    is also no, you don't need to do that. But you could.
>
> When you think about what CTDB is for Samba, namely just
> the provider of its databases, and what you have to do
> in a non-clustered environment, the steps you need to
> take to put a clustered samba server into a new domain
> should be fairly obvious:
>
> on a high level generally
>
> - stop winbind (and samba)
> - leave the domain
> - enter new domain
> - start winbind (and samba)
>
> Of yourse for a clustered server, there are a few details:
> If you simply stop winbindd, then ctdb will get unhealthy.
>
> In order to perform the net ads leave/join operations,
> ctdb needs to be running, so you can't simply stop it.
>
> One option is to
> - stop ctdb
> - remove CTDB_MANAGES_SAMBA/WINBIND
> - start ctdb
> - net ads leave
> - modify config
> - net ads join
> - stop ctdb
> - add CTDB_MANAGES_SAMBA/WINBIND
> - start ctdb
>
> If you want to avoid complete cluster downtime
> though (e.g. for other services), then you can:
>
> - ctdb disablescript 50.samba
> - CTDB_BASE=/etc/ctdb bash /etc/ctdb/events.d/50.samba shutdown
> - ctdb disablescript 49.winbind
> - CTDB_BASE=/etc/ctdb bash /etc/ctdb/events.d/49.winbind shutdown
> - net ads leave
> - modify config
> - net ads join
> - CTDB_BASE=/etc/ctdb bash /etc/ctdb/events.d/49.winbind startup
> - ctdb enablescript 49.winbind
> - CTDB_BASE=/etc/ctdb bash /etc/ctdb/events.d/50.samba startup
> - ctdb enablescript 50.samba
>
> Note: the extra steps with 49.winbind only apply to ctdb 2.5 and
> newer. Older versions only have 50.samba.

Thank you for that very detailed reply. However, wouldn't we have to
perform the samba shutdown and winbindd shutdown on all nodes in the
cluster, and then after having done the unjoin and the join, perform
the startup on each node in the cluster?

-- 
Regards,
Richard Sharpe
(何以解憂？唯有杜康。--曹操)