Adding servers to existing ESX 3.X clusters

[ivoryt]

I am running esx 3.0.1 as a 3 node cluster (DL580) dual core) and want to add two servers from an an older cluster pre a migration. These servers are DL740 single core processor boxes. The new cluster is running on a HP EVA8100 and there are 2 vmfs luns presented to it.

Is it possible to A, add the older servers to this cluster or B, if not form a new cluster of the older servers and present that to the existing LUNS.

PS is there a writtren propcedure somewhere for adding ESX servers to an existing SAN connected cluster?

Regards Terry....

[Anders_Gregerse]

You can add your Hosts to your existing cluster with vm's on them, but you can't remove a server from a cluster without placing it in maintenance mode. Hosts in a cluster can be connected to different SANs, but you should be aware that it will limit the functionality of the cluster (not being able to move vm's freely around the hosts in the cluster). If you don't expect the hosts to see the same SAN you might as well have two clusters one for each SAN.

[ivoryt]

Thanks Anders, I was really wondering if it was possible to create a new cluster with new Hosts and have these sharing the SAME vmfs voumes as the existing cluster. I realise I won't be able to use Vmotion etc but can I have VM's from two different clusters running on the same VMFS volume? Alternatively, is it possible to have an additional host which is not in a cluster sharing the same vmfs as the cluster.

The reason for this is I do not think the servers I propose to add to the cluster are compatible. The existing ones are Dual core HP DL580's. the ones I want to add are single core HP DL740's

[Anders_Gregerse]

Hosts can share one or more SAN volumes without being in the same cluster. You can use vmotion between two hosts as long as they can see the same storage and network that the vm are using (but I don't know if you can vmotion a vm from a host in one cluster to a host in another cluster, but I can't why it shouldn't be possible). You might be able to get vmotion to work between your single core and multiple core based servers. Either HP or vmware has some whitepapers on that topic.

[daniel-san]

Hi there.

You can have your diffrent clusters to share VMFS. You can also use vmotion between them if the processors are in the same processorgroup. You should look that up in the compability list for processors. If thats not the case, you might want to check exakly why not and maybe mask out that problem. But you need to look in a little bit closer to that.

Regards

Daniel