[Pacemaker] some questions about STONITH

[Digimer]

On 19/11/13 14:06, Andrey Groshev wrote:
> 
> 
> 19.11.2013, 22:30, "Lars Marowsky-Bree" <lmb at suse.com>:
>> On 2013-11-19T22:10:29, Andrey Groshev <greenx at yandex.ru> wrote:
>>
>> First, like digimer wrote, clearly stonith-by-ssh is useless for
>> production since you can't fence nodes that are having problems. But for
>> testing, it's worth a try.
> 
> Maybe I do not quite understand correctly the term "fence"
> If I want I can restart the server with the software profile, which will turn off all services except SSH.

Fencing is designed to put a node in an unknown state into a known
state. It guarantees that a node will not offer clustered services or
access clustered resources after it is declared lost.

Without fencing, a condition called "split-brain" (two or more nodes
offering the same HA services at the same time without coordinating)
becomes very possible. With shared storage, data divergence and data
loss are also quite possible. Fencing, when used properly, prevents
these conditions from occurring.

-- 
Digimer
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