[Pacemaker] pacemaker resource constraints

[Andrew Beekhof]

On Mon, Mar 22, 2010 at 9:18 PM, Alan Jones <falancluster at gmail.com> wrote:
> Well, I guess my configuration is not as common.
> In my case, one of these resources, say resource A, suffers greater
> disruption if it is moved.
> So, after a failover I would prefer that resource B move, reversing the node
> placement.
> Is this possible to express?

Make A stickier than B.

Please google for the following keywords:
    site:clusterlabs.org resource-stickiness

> Alan
>
> On Mon, Mar 22, 2010 at 11:10 AM, Dejan Muhamedagic <dejanmm at fastmail.fm>
> wrote:
>>
>> Hi,
>>
>> On Mon, Mar 22, 2010 at 09:29:50AM -0700, Alan Jones wrote:
>> > Friends,
>> > I have what should be a simple goal.  Two resources to run on two nodes.
>> > I'd like to configure them to run on separate nodes when available, ie.
>> > active-active,
>> > and provide for them to run together on either node when one fails, ie.
>> > failover.
>> > Up until this point I have assumed that this would be a base use case
>> > for
>> > Pacemaker, however, it seems from the discussion on:
>> > http://wiki.lustre.org/index.php/Using_Pacemaker_with_Lustre
>> > ... that it is not (see below).  Any ideas?
>>
>> Why not just two location constraints (aka node preferences):
>>
>> location l1 rsc1 100: node1
>> location l2 rsc2 100: node2
>>
>> Thanks,
>>
>> Dejan
>>
>> > Alan
>> >
>> > *Note:* Use care when setting up your point system. You can use the
>> > point system if your cluster has at least three nodes or if the resource
>> > can acquire points from other constraints. However, in a system with
>> > only two nodes and no way to acquire points, the constraint in the
>> > example above will result in an inability to migrate a resource from a
>> > failed node.
>> >
>> > The example they refer to is similar to yours:
>> >
>> > # crm configure colocation colresOST1resOST2 -100: resOST1 resOST2
>>
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>>
>>
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>
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