[Samba] CTDB and PDC Role

Ciro Iriarte cyruspy at gmail.com
Tue Nov 2 15:46:10 MDT 2010

2010/11/2 Volker Lendecke <Volker.Lendecke at sernet.de>:
> On Tue, Nov 02, 2010 at 06:48:38PM +0000, Alex Crow wrote:
>> I asked a question like this ages ago:
>> If you had a shared filesystem between the PDC and BDC(s) then
>> surely you wouldn't need to migrate your BDC to a PDC automatically,
>> you could do it at your leisure.
> Well, depending on your passdb backend this might or might
> not work. I would not count on file system failover to get
> the passdb.tdb right in all cases. Probably I am too
> paranoid here, as we're using proper tdb transactions these
> days, but between a CPU and a disk spindle in a SAN setup
> too much can go wrong for my taste.
> The main difference between a PDC and a BDC in a Samba setup
> is the "domain master = yes/no". It is really just a matter
> of setting that to yes and a restart of smbd and nmbd to
> promote a BDC to a PDC.
>> For your logon scripts and profiles in your LDAP you'd just point to
>> a virtual IP/hostname of the PDC/BDC cluster.
>> Volker, would this work?
> Details pending, the general idea sounds okay. But please be
> aware that in HA setups so much can go wrong that it's not
> funny anymore. The devil is really in the details.
> Volker

So, what's the recommended approach in general using Samba3?. Having a
multimaster LDAP directory helps to accept any password modification
while the PDC is down, what about fileserving?, using another IP for
that service and moving it with the FS from one node to another would
work (am I right?).

If the missing WINS service breaks the network, would a single samba
instance moved as a resource between nodes be better that a PDC/BDC


Ciro Iriarte

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