[Pacemaker] Three questions...

[Takenaka Kazuhiro]

Hello

> It is completely dependent on your stonith architecture.
> Some devices support a list of hosts which means you only need one
> stonith resource.

Even if there is a such device, the Pacemaker stonith mechanism
provides insufficient support for it. Suppose: how should its plugin
instance do when it loses control to one of its target nodes? If a
monitor for the instance returns an error code, Pacemaker loses control
via it to all of its target nodes at a time. On the other hand, If a
monitor for the instance returns a success code, Pacemaker cannot
be aware of the trouble. In the later case, when the node that the
instance cannot control must be shooted, Pacemaker will request
the useless instance to shoot the node.

Andrew Beekhof wrote:
> 2009/3/16 Romi Verma <romi3rdfeb at gmail.com>:
>>>
>>> i guess if DC fails then CRM will elect any other node for DC role and
>>> then , this new DC  will try to fence the errant node , if it fails to fence
>>> then it will choose other node for this fencing task.
>>  Andrew could you please confirm the above .
> 
> [insert same rant as Lars - this is getting _really_ annoying]
> 
>> one thing more related to stonith design. suppose we have 4 nodes cluster so
>> do we need 3 stoniths on each node ( to make a node eligible to kill any of
>> other 3 nodes ) that will lead to 3x4 stoniths or  do we need only  one
>> stonith on  each node that will be total 4 stoniths .
> 
> It is completely dependent on your stonith architecture.
> Some devices support a list of hosts which means you only need one
> stonith resource.
> 
>> i experimented this and found that 3 stoniths on each node is required but i
>> guess it should not be the c ase as CIB has the stonith info so even if
>> stonith is not running on a node it shoul be able to  read the stonith
>> related info from CIB.
>>
>> Thanks,
>>>
>>> Thanks & Regards,
>>>
>>>>
>>>> Regards,
>>>>
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>>
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> 
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-- 
Takenaka Kazuhiro <takenaka.kazuhiro at oss.ntt.co.jp>