[DRBD-user] Split brain when starting resources by Pacemaker

[Carlos Xavier]

Hi Felix.

Tank you very much to sharing your point of view, so it seams that the 
temporary solution I took it will be a permanent solution.
Besides DRBD is being started outside of Pacemaker, Pacemaker is aware of 
DRBD by the device and by the filesystem. I tested stopping DRBD and 
starting it again and the partition got umounted ad mounted again, even on 
reboots :-).
Although sometime i need to do a resouce cleanup to get all the things 
working as it should.

Kind regards,
Carlos.


----- Original Message ----- 
From: "Felix Frank" <ff at mpexnet.de>
To: "Carlos Xavier" <cbastos at connection.com.br>
Cc: <drbd-user at lists.linbit.com>
Sent: Wednesday, August 29, 2012 4:34 AM
Subject: Re: [DRBD-user] Split brain when starting resources by Pacemaker


> On 08/28/2012 10:55 PM, Carlos Xavier wrote:
>> Hi.
>>
>> Since there was no one hint to solve this trouble, the only temporary
>> solution I found to allow me to continue with the cluster configuration
>> was wipe out all the related DRBD configuration from the crm and start
>> the DRBD resources by the /etc/init.d/drbd init script.
>>
>> If someone have another solution I´ll be glad to hear about.
>>
>> Kind regards,
>> Carlos.
>
> Hi,
>
> I believe the problem is that pacemaker is not yet very well equipped to
> handle dual-primary setups (at least to my knowledge).
>
> In a traditional primary/secondary setup, a node becoming master can
> fence its peer and give you some safety against split brains. It's much
> more complex for dual-primary. You would basically need to teach
> pacemaker to remember which node left the cluster last, and make sure
> the other node does not get to work standalone.
>
> Again, I disbelieve that's currently possible. Maybe there's a simpler
> solution, though.
>
> Regards,
> Felix
>
>