[Pacemaker] DRBD primary/primary + Pacemaker goes into split brain after crm node standby/online

[Alexis de BRUYN]

On 12.06.2014 22:44, Lars Ellenberg wrote:
> On Mon, Jun 09, 2014 at 08:07:51PM +0200, Alexis de BRUYN wrote:
>> Hi Everybody,
>>
>> I have an issue with a 2-node Debian Wheezy primary/primary DRBD
>> Pacemaker/Corosync configuration.
>>
>> After a 'crm node standby' then a 'crm node online', the DRBD volume
>> stays in a 'split brain state' (cs:StandAlone ro:Primary/Unknown).
>>
>> A soft or hard reboot of one node gets rid of the split brain and/or
>> doesn't create one.
>>
>> I have followed http://www.drbd.org/users-guide-8.3/ and keep my tests
>> as simple as possible (no activity and no filesystem on the DRBD volume).
>>
>> I don't see what I am doing wrong. Could anybody help me with this please.
> 
> Use fencing, both node-level fencing on the Pacemaker level,
> *and* constraint fencing on the DRBD level:
Thanks Lars, it is working fine now.

> 
>> # cat /etc/drbd.d/sda4.res
>> resource sda4 {
>>  device /dev/drbd0;
>>  disk /dev/sda4;
>>  meta-disk internal;
>>
>>   startup {
>>     become-primary-on both;
>>   }
>>
>>   handlers {
>>     split-brain "/usr/lib/drbd/notify-split-brain.sh root";
> 
>  fence-peer crm-fence-peer.sh;
>  after-resync-target crm-unfence-peer.sh;
> 
>>   }
> 
>  	disk {
> 	 fencing resource-and-stonith;
> 	 }
> 
>>
>>   net {
>>     allow-two-primaries;
>>     after-sb-0pri discard-zero-changes;
>>     after-sb-1pri discard-secondary;
>>     after-sb-2pri disconnect;
>>   }
>>  on testvm1 {
>>   address 192.168.1.201:7788;
>>  }
>>  on testvm2 {
>>   address 192.168.1.202:7788;
>>  }
>>
>>  syncer {
>>   rate 100M;
>>   al-extents 3389;
>>  }
>> }

-- 
Alexis de BRUYN