[Pacemaker] Strange behaviour of dual master DRBD

[Lars Ellenberg]

On Thu, Sep 10, 2009 at 05:10:39PM +0200, Michael Schwartzkopff wrote:
> Hi,
> 
> I configured a dual master DRBD-8.3.2. When the nodes stat there is no problem. 
> Both DRBD become master. But when I set on node to standby and wake it up 
> again, the DRBD on that node stays secondary and does not become master.
> 
> My config:
> primitive resDRBD ocf:linbit:drbd params drbd_resource="r0"
> ms msDRBD resDRBD meta notify="true" master-max="2"
> 
> No further constraints.
> 
> When the second node is online again ptest -sL shows:
> (...)
> resDRBD:0 promotion score on suse2: 50
> resDRBD:1 promotion scpre on suse1: -1
> 
> Since the "-1" prevents the resource from beein promoted, I understand the 
> behaviour of the cluster, but why isn't the resource beeing allowed th become 
> master on that node?
> 
> Thanks for any enlightenting answers.

Most likely it prevents you from shoting yourself in the foot ;)

look at /proc/drbd and the kernel logs (appart from the ha.log, of
course) on the drbd nodes to find out more.
I bet you manoevered yourself into diverging data sets (aka DRBD "split brain").

If it turns out to be a drbd.ocf bug,
let me know.

-- 
: Lars Ellenberg
: LINBIT | Your Way to High Availability
: DRBD/HA support and consulting http://www.linbit.com

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