Cluster IP migration

Hi,


I need to change IPs of both nodes of a 2 nodes (up to date) unicast cluster with no downtime of any VM. (old IPs: 88.x.x.x, new ones: 195.x.x.x)


I planned to:
- move all VMs from one node (B) to the other (A)
- change B IP
- migrate back all VMs from A to B
- change A IP
- dispatch VMs like they were at the beginning


So far so good, I tried the following:
- move all VMs from node B to node A
- change IP of node B in
/etc/network/interfaces
/etc/hosts
also change /etc/hosts in node A
- /etc/init.d/networking restart (node B)


this led to node B glowing red in the cluster, and no VM migration possible.


- reboot node B


not better


- restore previous network config in the previously changed files
- /etc/init.d/networking restart (node B)


cluster still down


- reboot node B


cluster finally restored, back to start.


Since the new IPs are in different ranges than the old ones, I’m not sure if I have any chance to make a temporary cluster with node A in the old range and node B in the new one.


Removing node B from the cluster, moving IPs of both nodes and setting again node B in the cluster doesn’t feel that safe, according to:
http://pve.proxmox.com/wiki/Proxmox_...a_cluster_node


What is the safest way to operate this migration?