[Samba] CTDB and nfs-ganesha

[Martin Schwenke]

Hi Max,

On Sat, 5 Oct 2019 10:58:12 +0000, Max DiOrio
<Max.DiOrio at ieeeglobalspec.com> wrote:

> I’ll have to check out the script issue on Monday.

> You said the lock needs to be the same on all nodes.   I can do that
> but this is now in production and restarting the ctdb service forces
> a failover of the ip, which actually causes a failure of a few of our
> Kubernetes sql database pods - they freak out and don’t recovery if
> storage is ripped out from under them.

> Is there a way to do this without an ip takeover on each node when
> ctdb is restarted?

There are 2 ways.

The first is the NoIPTakeover tunable (see ctdb-tunables(7)).  The
current semantics of this is that it is evaluated on the recovery
master node.  If you set it on all nodes (in /etc/ctdb/ctdb.tunables on
the any nodes you take down, or using "ctdb setvar NoIPTakeover 1" on
any nodes that are up... note that it only survives reboots if it is
in ctdb.tunables) then that should do what you want.

However, I think the easiest option is to temporarily empty the
/etc/ctdb/public_addresses file (comment out all lines?) on the nodes
that you don't want taking over addresses when you restart them.  When
you finally want takeover to occur then uncomment the addresses and run
"ctdb reloadips <node>" for the <node> in question.  That will cause
that node to reload its nodes file and trigger a failover.  Or just
uncomment the addresses and restart CTDB.  ;-)

> Thanks. This is slowly starting to make sense.

I'm glad.  If you can think of particular documentation that can be
improved then please point me at it...  or send a patch! :-)

peace & happiness,
martin