Vcenter consolidation/migration

[renalpete]

Hi,

We currently have two unlinked vcenter 5 deployments, each handling up to a dozen ESX servers (mostly v5). We have quite a lot of VMs, clusters etc. Fairly shortly we are moving office, which will result in a change of IP address and DNS for the vcenter and ESX hosts. Ideally we would like to consolidate the two vcenter setups into one, though initially we'd settle for both setups continuing to work!

Can anyone offer any advice, or point me at KBs etc to help me come up with a plan for the migration?

Thanks!

Pete

[GreatWhiteTec]

Consolidating the vCenters into one is fairly easy. Just move VMs and host into the one vCenter. You may have to alternate between hosts and VMs to make sure you always have enough capacity and room for redundancy.

A change of ip for the vCenter, hosts, VMs sounds like a really big task. Just changing the IP address of one VM alone can make an application stop working. You would need to do a lot of testing on the Applications.

I recently did a similar migration but in a small scale. I created a new vCenter in the new network and moved hosts and VMs after testing.

[renalpete]

The two vcenters are on different networks, so I can't currently connect to both at once. When you say "move VMs and host into the one vCenter", what exactly do you mean - if ESX hosts A1 and A2 are managed by vcenter A, B1+B2 managed by vcenter B, do I connect the client to A, and add a host B1? I thought that all the cluster/folder definitions lived only on vcenter, and would be lost if I "remanaged" the ESX host. Is that not correct?

The addressing of hosted VMs is a decent sized job, but something we know how we're going to handle - my main concern is losing the vcenter setup (hierarchy of VMs etc)

[GreatWhiteTec]

OK got it. I was under the impression the 2 vCenter were under the same network. So, I am guessing the new office will have a new subnet? or can you just use the current network of the vCenter you plan to move?

Changing the IPs of the host is pretty easy, the vCenter IP change does have some steps.

http://communities.vmware.com/thread/119886

[renalpete]

Yep, we're moving from two unlinked subnets to two new, linked subnets. Those steps look fairly straightforward, probably we will hack up something so that we can renumber the vcenter first, still have it talk to the esx hosts on their old addresses, then renumber the ESX hosts to the new addresses one by one.

Could you provide some more details about the consolidation of vcenters? As I say, I'm worried that we'll lose fancy setup (clusters, folders etc) if we just remanage hosts to a different vcenter setup...

[GreatWhiteTec]

You would have to recreate your "fancy setup" on the target vCenter, unless you have it set up in a similar way. Migrating the hosts to the one vCenter won't get you your settings from the source vCenter, you are just adding more hosts to the vCenter.

In my opinion, recreating your settings on the target vCenter and migrating the hosts will minimize down time and the potential of messing up the vCenter.

Once you create your Clusters and vApps, or whatever else you have, you can migrate 1 host, set it up as the it was and create a host profile so you can apply the same settings to the other hosts as you move them.

I guess you have to pick your poison.

[renalpete]

We've probably got a couple of hundred VMs, I'm really not keen to lose the setup we currently have...

[GreatWhiteTec]

New IP for the vCenter then. Make sure you get a backup before. Good luck.