[Linux-cluster] frozen services are stopped when rgmanager is restarted

[Tom Lanyon]

On 22/06/2010, at 1:20 AM, Martin Waite wrote:
> Hi,
> 
> RHEL 5.4:  cluster2 (I think).
> 
> I expected to be able to freeze a service on a node and restart rgmanager on that node without interrupting the service.   In practice, starting rgmanager causes the service to be stopped. 
> 
> Is this what is supposed to happen ?  I thought the whole point of freezing services was to allow maintenance (including restarting cluster software).
> 
> Are there any options to prevent the services from being stopped when rgmanager is started ?
> 
> One effect of rgmanager stopping the service is that the cluster reaches an inconsistent state.  Once rgmanager has restarted, the cluster believes that the services are still frozen, where in reality they are stopped.   Any attempt to unfreeze the service causes the service to failover to a standby node.

I did this recently to upgrade rgmanager on a production cluster with no downtime to services, however I can't find the reference materials I used to do so...

The basic steps are:

* freeze all services
	/usr/sbin/clusvcadm -Z <service>
* stop rgmanager
	/sbin/service rgmanager stop
* upgrade rgmanager 
	yum upgrade rgmanager
* restart rgmanager manually, using the -N flag
	/usr/sbin/clurgmgrd -N
* wait until rgmanager is running again (check 'clustat' output)
* unfreeze the services
	/usr/sbin/clusvcadm -U <service>

Tom