[Pacemaker] Proper way to migrate multistate resource?

[Lars Ellenberg]

On Tue, Feb 07, 2012 at 02:03:32PM +0100, Michael Schwartzkopff wrote:
> > On Mon, Feb 06, 2012 at 04:48:26PM -0800, Chet Burgess wrote:
> > > Greetings,
> > > 
> > > I'm some what new to pacemaker and have been playing around with a
> > > number of configurations in a lab. Most recently I've been testing a
> > > multistate resource using the ofc:pacemaker:Stateful example RA.
> > > 
> > > While I've gotten the agent to work and notice that if I shutdown or
> > > kill a node the resources migrate I can't seem to figure out the
> > > proper way to migrate the resource between nodes when they are both
> > > up.
> > > 
> > > For regular resources I've used "crm resource migrate <rsc>" without
> > > issue. However when I try this with a multistate resource it doesn't
> > > seem to work. When I run the command it just puts the slave node into
> > > a stopped state. If I try and tell it to migrate specifically to the
> > > slave node it claims to already be running their (which I suppose in a
> > > sense it is).
> > 
> > the crm shell does not support roles for the "move" or "migrate" command
> > (yet; maybe in newer versions. Dejan?).
> > 
> > What you need to do is set a location constraint on the role.
> >  * force master role off from one node:
> > 
> > 	location you-name-it resource-id \
> > 		rule $role=Master -inf: \
> > 		#uname eq node-where-it-should-be-slave
> > 
> >  * or force master role off from all but one node,
> >    note the double negation in this one:
> > 
> > 	location you-name-it resource-id \
> > 		rule $role=Master -inf: \
> > 		#uname ne node-where-it-should-be-master
> 
> These constraints would prevent the MS resource to run in Master state even on 
> that node. Even in case the preferred node is not available any more. This 
> might be not what Chet wanted.

Well, it is just what crm resource migrate does, otherwise.

After migration, you obviously need to "unmigrate",
i.e. delete that constraint again.


-- 
: Lars Ellenberg
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