Moving ESX 4.0 Hosts to a VCenter-Server in different Windows Domain

[MMT201110141]

Hi folks,

Current situation: Two ESX 4.0 hosts controlled by a VCenter 4.0 Server (Cluster) inside a Windows 2003 – Domain. All user access control is done with domain users of the old domain. The cluster and all VMs are running fine without any problems.

There is a new Windows 2008 Domain. We want to set up a new VCenter 4.0 Server inside the new Domain and move the two ESX 4.0 hosts to the new cluster / VCenter 4.0 Server.

What is the right way to do this without locking me out of Vcenter / ESX?

1)      Set up the new VCenter Server an create a cluster

2)      Removing the two ESX Servers from the old cluster

3)      Joining the two ESX Servers to the new cluster

4)      Grant domain users of the new domain access to VMs, …

Is it really that easy?

What accounts do I need to join the two ESX-hosts to the new cluster/vcenter? The root-Passwort? We forgot it, but there is a way to reset it (Single user mode), this should not be a big problem.

Thanks for your kind support,

Wolfgang

[piaroa]

Hey there, your procedure looks good.

If you lost your root ESXi password, you can try these steps to reset it, should work fine:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=131789...

[MMT201110141]

Thank you for the KB-article.

So do I only need the root password to join the new cluster? Wow, that would be really easy.

I will try this evening (i cannot reboot the server in production hours...).

Kind regards,

Wolfgang

[piaroa · Accepted solution]

You need to add the hosts to the new cluster via their DNS names, and provide the root password when prompted.

Make sure you select "graft resource pools from host" if you want to keep your pools on the new vCenter. For that you need to enable DRS in the new cluster too.

[piaroa]

Also, when disconnecting from your old vCenter and adding to your new vCenter you don't need to reboot your ESX host. Your VMs will keep working and there is no downtime in this step.

Make sure you click on disconnect, then add the host to the new vCenter and then after you verify all is good, click on Remove from the old vCenter.

[idle-jam]

it's that simple, even if your vcenter is down your host will still continue to operate normally. there after just make sure the HA cluster is working fine by right click and enable HA. (if you have VMware HA)

[piaroa]

On the subject of HA, it's always good to "disable host monitoring" (but not HA), when doing these migrations, to avoid HA acting up. Edit your cluster's settings and you will see an option to disable monitoring.

When you are all set in the new vCenter check HA settings and enable host monitoring, etc.

[MMT201110141]

Thank you for the replies.

I will have to reboot the servers - lost root password.

Downtime will be on Saturday.

Thank you very much.

Kind regards,

Wolfgang

[MMT201110141]

Migration is done – all went well. :smileycool:

The only big problem was resetting the root-password on ESXi 4.0! We needed to boot with a Linux-Rescue CD (Knoppix), unpack the “state.tgz”, extract the “local.tgz” and remove the password-hash from the /etc/shadow-File for root.

There is no grub on ESXi – the document from the KB did not work.

Removing the ESX-hosts from the old cluster was only possible by going into maintenance mode. Adding to the new cluster was absolutely no problem – all VMs, all datastores were there.

Thank you for your support.

Kind regards,

Wolfgang