[PVE-User] Network migration of a hyper-converged cluster

[Iztok Gregori]

Hi to all!

I'm planning to migrate the network of a hyper-converged Proxmox cluster 
to a different subnet and I'm searching for some advice on how to do 
that without downtime and without the need to reinstall the nodes.

The migration will be performed one node at the time and the node will 
be emptied from VMs (via live-migration) also the "noout" parameter will 
be enabled to avoid unnecessary data movement. The "empty" nodes can be 
restarted if needed.

For Ceph I was thinking to add the new network to "public_network" and 
"cluster_network" (those 2 are the same), so Ceph will be ready to 
accept "requests" from the IPs of the new network. After that, I'm less 
sure of how to handle the configuration of monitors/managers. I was 
thinking something like that:

- Destroy the monitor/manager daemon (if the node has one).
- Stop OSDs.
- Change Node IP.
- Start OSDs (or restart the node).
- Recreate the monitor/manager.

Am I missing something?

I have more doubts about how to migrate Proxmox network (corosync). I 
think that I'll need to add a new "ring" network in corosync.conf with 
the nodes new IPs, so once the node changes its IP address it will be 
seen again "UP". At the end of the migration I'll remove the old "ring" 
network. Is it feasible or it will not work?

Any other advice or experiences are welcome!

Cheers
Iztok
-- 
Iztok Gregori
ICT Systems and Services
Elettra - Sincrotrone Trieste S.C.p.A.
Telephone: +39 040 3758948
http://www.elettra.eu