[Pacemaker] Renumbering cluster

[Chris Adams]

I have a two node cluster for NFS service.  The servers are running
CentOS 6.5 with corosync-1.4.1 and pacemaker-1.1.10.  They each have a
pair of NICs bonded together running a VLAN trunk, with interfaces
vlan10 and vlan11.  The "main" IP on each server is on vlan10, and
that's where the cluster communication takes place (the servers don't
actually have individual IPs on vlan11, just a cluster-managed IP for
NFS service).

I need to replace vlan10 with vlan9 (different subnet), changing the
"main" IP used for cluster communication.

I assume that I could do it by:

- add the new VLAN interface and IP on each node
- shut down cluster services on both nodes
- change /etc/hosts entries to point to the new IPs
- start cluster services on both nodes

But that would require a service outage I'd like to avoid if practical.
Is there another (better) way?

-- 
Chris Adams <linux at cmadams.net>