[ClusterLabs] Recovering after split-brain

[Digimer]

On 21/06/16 01:05 PM, Dimitri Maziuk wrote:
> On 06/21/2016 11:47 AM, Digimer wrote:
> 
>> If you don't need to coordinate services/access, you don't need HA.
>>
>> If you do need to coordinate services/access, you need fencing.
> 
> So what you're saying is we *cannot* run a pacemaker cluster without a
> tiebreaker node *and* a network-controlled power socket.
> 
> I knew that, actually, that's why I hung on to heartbeat for as long as
> I could. It'd be nice to have it spelled out in bold at the start of
> every "explained from scratch" document on clusterlabs.org for the young
> players.

Quorum is optional. Fencing is not.

If you run a 2-node cluster, then you just need to take a couple
precautions, like adding 'delay="15"' to the preferred node's stonith
definition so that it will win if comms break.

Last I checked, CfS did emphasize the need for stonith. I know I
certainly explain it (over and over again) whenever it comes up.

-- 
Digimer
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