[Pacemaker] Configuring Pacemaker & DRBD

[Andreas Kurz]

On 10/10/2011 06:04 PM, Cliff Massey wrote:
> How does stonith work in a 2-node cluster? There aren't enough nodes to make quorum and vote the bad guy out.
> 

You need to set no-quorum-policy to ignore ... the faster one wins in a
real split brain ... if the stonith connection is still up.

So avoiding a split brain by using several independent communication
paths (including the stonith network if possible) and using direct
connected links will limit most of the stonith events to "real"
incidents and then only one node will try to fence the other, dead node.

Failed stop events will also trigger stonith by default...

Regards,
Andreas

-- 
Need help with Pacemaker?
http://www.hastexo.com/now

> 
> On Oct 7, 2011, at 4:31 PM, Cliff Massey wrote:
> 
>> ahh makes sense.
>>
>> I disabled allow-migrate and now I can move the kvm machine and at the same time drbd is automatically set to primary on the new node. 
>>
>> Time to setup stonith.
>>
>> On Oct 7, 2011, at 4:13 PM, Florian Haas wrote:
>>
>>> On 2011-10-07 21:23, Cliff Massey wrote:
>>>> I  meant 8.40 :)
>>>>
>>>> I ended up deciding to use Corosync instead of Heartbeat and it is working now. Now I'm configuring a KVM resource to depend on drbd. The KVM machine is started by Pacemaker,  but when I try "resource migrate" to move it to the other node nothing happens.
>>>
>>> Yeah, can't work. For a resource with meta allow-migrate=true to
>>> migrate, anything which that migrating resource depends on must already
>>> be present on the target node. Which, when your KVM resources use DRBD,
>>> can only ever work in a dual-Primary configuration. So, either set
>>> allow-migrate to false (so migration reverts to the default "shut down
>>> here, fire up there" method), or -- if and only if you're familiar with
>>> its implications -- set up a DRBD dual-Primary configuration.
>>>
>>> Cheers,
>>> Florian
>>>
>>> -- 
>>> Need help with DRBD?
>>> http://www.hastexo.com/now
>>>
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>>
>>
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>>
> 
> 
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