[Linux-HA] Can't get the ping_group to work - problem with location constraints and DRBD

[Tobias Appel]

On Fri, 2009-01-30 at 12:16 +0100, Dejan Muhamedagic wrote:
> Hi,
> 
> On Fri, Jan 30, 2009 at 11:35:54AM +0100, Tobias Appel wrote:
> > Hi,
> > 
> > I'm using Heartbeat 2.1.4 and I tried to setup a ping_group so that if I
> > pull the ethernet cables on one of the two nodes a failover will occur.
> > 
> > I have configured a ping_group group 1 in ha.cf and created a clone
> > resource with pingd.
> > 
> > The problem is, I have a resource group + a master / slave resource for
> > DRBD. the resource group only runs on the node which is currently
> > master. Now I added another constraint for pingd, so that the failover
> > occurs, but it does not work - nothing is happening, I think it has to
> > do with the DRBD resource. Here are my current constraints:
> > 
> >  <constraints>
> >    <rsc_order id="order_drbd_filesys" from="nagios" action="start"
> > to="ms_drbd" to_action="promote"/>
> >    <rsc_colocation id="colocation_drbd_filesys" to_role="Master"
> > from="nagios" to="ms_drbd" score="INFINITY"/>
> >    <rsc_location id="location_resources" rsc="ms_drbd">
> >      <rule id="prefered_location_resources" score_attribute="pingd">
> >        <expression attribute="pingd"
> > id="66155d1f-2210-45ad-9010-a14e48825ead" operation="defined"/>
> >      </rule>
> >    </rsc_location>
> >  </constraints>
> > 
> > I'm not quite sure how to change the location constraint to the
> > following:
> > -if you are the active node and the ping group is not reachable, stop
> > resource group "nagios"
> > - promote the other node to master for ms_drbd and start resource group
> > nagios there
> 
> Add role=Master to the pingd location constraint. I think this
> was also described in the drbd howto.

I have read the DRBD howto's on linux-ha.org but this is only for the
basic setup, of course with a resource group, but not with pingd and
drbd and a resource group. I added role="Master" to the constraint but
it still will not work:

<rsc_location id="location_resources" rsc="ms_drbd">
     <rule id="prefered_location_resources" score_attribute="pingd"
role="Master">
       <expression attribute="pingd"
id="66155d1f-2210-45ad-9010-a14e48825ead" operation="defined"/>
     </rule>
   </rsc_location>

Btw, I did find some useful info here (even if it is for pacemaker):
http://www.clusterlabs.org/wiki/DRBD_HowTo_1.0

But like I said, it still does not work. Heartbeat does not stop the
resource group and does not promote the other node to master. Logfile
still says:

Jan 30 12:07:07 nagios2 pengine: [3758]: info: master_color: Promoting
resource_drbd:0 (Master nagios2)
Jan 30 12:07:07 nagios2 pengine: [3758]: info: master_color: ms_drbd:
Promoted 1 instances of a possible 1 to master
Jan 30 12:07:07 nagios2 pengine: [3758]: info: master_color: ms_drbd:
Promoted 1 instances of a possible 1 to master
Jan 30 12:07:07 nagios2 pengine: [3758]: notice: NoRoleChange: Leave
resource resource_filesys  (Started nagios2)

and so on...

one would not believe how complicated the most basic check for network
connectivity can be. *sigh*

> 
> > The logfile looks like this (especially line 3 mentions the problem with
> > DRBD master):
> > 
> > Jan 30 10:24:12 nagios2 pengine: [3758]: WARN: text2task: Unsupported
> > action: status
> 
> You should use monitor, not status. Don't know what does your
> configuration look like.
> 
I know, but I don't even know what text2task is. I don't have any
resource by that name and google didn't help much except that many
people have the same error message in their logfiles apparently but I
haven't figured out what kind of software that is.