High availibility with nodes in different subnet

[neeko]

Hello,

I have 3 proxmox nodes that use iscsi on freenas as thier storage backend. We have three sites all connected via a vpls. I would like to know if it would be possible to put one of the nodes in at a separate site from the other 2. This would leave me with 2 nodes and the freenas server in my server room (10.12.4.0/22) and one node in my CoLo data center (10.4.4.0/24). What I would like to happen is if the the site where the server room is located was to go offline for some reason the VM's that were there would be brought up @ the datacenter. This would allow our 3rd administrative site (10.32.4.0/22) access to all of our VM's.

The 2 questions that I have not resolved are:

• can a node live in a separate subnet?
• can machines on a node in 1 subnet with an IP of say 10.12.4.103 be brought up in another subnet without changing their IP?
• If yes to above, how would this be configured?

Any help would be greatly appreciated.

Thanks.

 

[spirit]

you need multicast for the cluster, the I think it's not possible.

also note that you can will lose quorum, if the link between your room and datacenter is down.

 

[screenie]

you could insert a vde2 switch in your network config and span the vlan over both locations - in this case all cluster nodes are in the same subnet;
but the quorum issue still exists like spirit already mentioned;