[Pacemaker] resource dependency
Hi list, I'm building a 4 node cluster where 2 nodes will export drbd devices via ietd iscsi target (storage nodes) and other 2 nodes will run xen vm (app nodes) stored in lvm partition accessed via open-iscsi initiator, using multipath to failover. Configuring the cluster resources order I came up with a situation that I don't find a solution. The xen vm resources depends of iscsi initiator resource to run, I have two iscsi initiator resources, one for each storage node, how can I make the vm resources dependent on any iscsi initiator resources ? I think in create a clone of the iscsi initiator resource, use rules to change the clone options in a way that I can have two clones per app node with different portal parameter. This way I could make the vm resouces dependency on this clone. Is this possible ? I'm using debian-lenny with the packages described at http://www.clusterlabs.org/wiki/Debian_Lenny_HowTo Excuse me for the bad english. Best Regards, Alexandre ___ Pacemaker mailing list Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker
Re: [Pacemaker] resource dependency
On Fri, Nov 20, 2009 at 2:53 PM, Matthew Palmer mpal...@hezmatt.org wrote: On Fri, Nov 20, 2009 at 02:42:29PM -0200, Alexandre Biancalana wrote: I'm building a 4 node cluster where 2 nodes will export drbd devices via ietd iscsi target (storage nodes) and other 2 nodes will run xen vm (app nodes) stored in lvm partition accessed via open-iscsi initiator, using multipath to failover. Configuring the cluster resources order I came up with a situation that I don't find a solution. The xen vm resources depends of iscsi initiator resource to run, I have two iscsi initiator resources, one for each storage node, how can I make the vm resources dependent on any iscsi initiator resources ? Personally, I think you've got the wrong design. I'd prefer to loosely couple the storage and VM clusters, with the storage cluster exporting iSCSI initiators which the VM cluster then attaches to the VMs as required. Put the error handling for the case where the iSCSI initiator isn't available for a VM into the resource agent for the VM. To me, this seems like a more robust solution. Tying everything up together feels like you're asking for trouble whenever any failover happens -- everything gets recalculated and the cluster spends the next several minutes jiggling resources around before everything settles back down again. Hi Matt, thank you for the reply. Ok. But if I go with your suggestion I end with the same question. Having the 2 node storage cluster exporting the block device via iSCSI, how can I make the VM resource at the VM cluster depend on *any* iSCSI target exported ? The standard order configuration just allow dependency on *one* resource. The only way I see is configure a ip resource on storage cluster and use this as portal on iSCSI initiator resource of VM cluster. I don't want to do this way because I think use multipath, for a quicked failover. Alexandre ___ Pacemaker mailing list Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker
Re: [Pacemaker] resource dependency
On Fri, Nov 20, 2009 at 4:35 PM, Andrew Beekhof and...@beekhof.net wrote: On Fri, Nov 20, 2009 at 5:42 PM, Alexandre Biancalana biancal...@gmail.com wrote: Hi list, I'm building a 4 node cluster where 2 nodes will export drbd devices via ietd iscsi target (storage nodes) and other 2 nodes will run xen vm (app nodes) stored in lvm partition accessed via open-iscsi initiator, using multipath to failover. Configuring the cluster resources order I came up with a situation that I don't find a solution. The xen vm resources depends of iscsi initiator resource to run, I have two iscsi initiator resources, one for each storage node, how can I make the vm resources dependent on any iscsi initiator resources ? The cluster can't express this case yet. But its on the to-doo list. Thank you for the answer Andrew and congratulations for this great peace of software. Best Regards, Alexandre ___ Pacemaker mailing list Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker
