Possible to set the specific order of a resource in a Pacemaker group?

Question

Given the Pacemaker/Corosync resource configuration described below, is it possible to add a resource in a specific position within the resource group? The configuration is CentOS 7.2 using the RHEL-supplied clustering add-ons.

This is a NFS server cluster, and Pacemaker handles the NFS daemon, volumes, exports, virtual-IP and NFS client notification.

When I want to add an NFS mount (exportfs resource) to the cluster setup, it ends up listed after the nfs-notify resource. This breaks the cluster in ugly ways.

I've found the rudimentary pcs resource order commands, which seem to allow specifying resource X needs to run before resource Y, but that's not scalable.

Is this possible?

[root@zfs1-node1 ~]# pcs status
Cluster name: zfs1
Last updated: Tue Jan  5 04:09:11 2016      Last change: Tue Jan  5 04:08:15 2016 by root via cibadmin on zfs1-node1
Stack: corosync
Current DC: zfs1-node1 (version 1.1.13-10.el7-44eb2dd) - partition with quorum
2 nodes and 9 resources configured

Online: [ zfs1-node1 zfs1-node2 ]

Full list of resources:

 fence-vol1 (stonith:fence_scsi):   Started zfs1-node1
 Resource Group: group-vol1
     vol1   (ocf::heartbeat:ZFS):   Started zfs1-node1
     nfs-daemon (ocf::heartbeat:nfsserver): Started zfs1-node1
     nfsinfo    (ocf::heartbeat:exportfs):  Started zfs1-node1
     vol1-management    (ocf::heartbeat:exportfs):  Started zfs1-node1
     vol1-ppro-mirrors  (ocf::heartbeat:exportfs):  Started zfs1-node1
     vol1-staging   (ocf::heartbeat:exportfs):  Started zfs1-node1
     ip-vol1    (ocf::heartbeat:IPaddr2):   Started zfs1-node1
     nfs-notify (ocf::heartbeat:nfsnotify): Started zfs1-node1

PCSD Status:
  zfs1-node1: Online
  zfs1-node2: Online

Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

No, the cluster resources were added in the right order initially. — ewwhite, Jan 05 '16 at 12:14
Would it be sufficient for your to insert your new resource at the right "place"? Do you've got `crm` available (or could install it)? — gxx, Jan 05 '16 at 12:18
I've got no `pcs` available, so I'm not sure, if this is possible as well, but using `crm configure edit` you would be able to directly edit the config. Keep an eye for line-breaks (marked via "\" (correct formatting doesn't work)) and indentation etc. I've just searched if `pcs` provides such an feature as well, but didn't found anything so far. — gxx, Jan 05 '16 at 12:26

score 4 · Accepted Answer · answered Jan 08 '16 at 00:04

You can use the cibadmin utility to query the Pacemaker configuration, move the primitives around accordingly within the <group id="group-vol1"></group> tags, and then push the new config back into Pacemaker.

The process would look something like this:

# cibadmin --query > /tmp/cib.xml
# vi /tmp/cib.xml
# cibadmin --replace --xml-file /tmp/cib.xml

When you edit cib.xml in vi, you will see your group defined by tags like this:
<group id="group-vol1"> *primitives within the group will go here* </group>

All the primitives will be defined inside of the group tags. They will look like this (ZFS primitive for example:
<primitive id="vol1" class="ocf" provider="heartbeat" type="ZFS"> *attributes and operations will go here* </primitive>

Move the primitives around as you'd like them to be ordered; top first, bottom last. Push the changes into Pacemaker, and you should be good.

Possible to set the specific order of a resource in a Pacemaker group?

1 Answers1