[Pacemaker] Question on ILO stonith resource config and restarting

[Dejan Muhamedagic]

Hi,

On Wed, Nov 05, 2008 at 09:27:06AM +0100, Andreas Mock wrote:
> > -----Urspr?ngliche Nachricht-----
> > Von: "Takenaka Kazuhiro" <takenaka.kazuhiro at oss.ntt.co.jp>
> > Gesendet: 05.11.08 03:32:08
> > An: The Pacemaker cluster resource manager <pacemaker at clusterlabs.org>
> > Betreff: Re: [Pacemaker] Question on ILO stonith resource config and restarting
> 
> Hi Takenaka-san,
> 
> > I think external/riloe isn't made to run as a clone resource
> > just same as external/ibmrsa-telnet. They are made to run in
> > a similar way to usual resource agents.
> > See the attached sample configuration.
> 
> I just asked Dejan some days ago what have to be done to make
> an external stonith plugin "cloneaware". He meant nothing.
> I never checked my ibmrsa-telnet running in a clone config.
> Therefore I'm really interested what went wrong running this
> plugin as a clone. Can you tell us your experiences?

Note that handling of clones is done on a different level, i.e.
by the CRM which decides where to run resources. The idea of
cloned stonith resources was to have "more" assurance that one of
the nodes which run the stonith resource may shoot the offending
node. Obviously, this may make sense only for clusters with more
than two nodes. On the other hand, if your stonith devices are
reliable and regularly monitored, I don't see any need for
shooting a node from more than one node. So, with the lights-out
devices which are capable of managing only its host (iLO, IBM
RSA, DRAC) I'd suggest having a normal (non-cloned) stonith
resource with a -INF constraint to prevent it from running on the
node it can shoot. This kind of power management setup seems to
be very popular and probably prevails today.

On larger clusters with stonith devices which may shoot a set of
nodes, a single cloned resource should suffice.

Does this help? A bit at least?

Thanks,

Dejan


> Best regards
> Andreas Mock
> 
> 
> 
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