Upgrading VC to vSphere 4

[khughes]

Quick question, we're getting ready to install vSphere 4 on our VC server. Plan of action was to just uninstall 2.5, and reinstall vSphere 4 for a clean install and new database ODBC connection.

Question is I've heard rumors that if you're uninstalling the VC you should remove the hosts from the cluster, but in order to remove the hosts from the cluster you need to be in maintanence mode, and that would mean I would need to shut down all the VM's to do it. Do I need to remove them from the cluster or can I just recreate it all afterwards?

I'm doing this in like 20 min so a speady answer is much appriciated.

• Kyle

[lamw · Accepted solution]

If you're going to uninstall the existing vCenter, you should probably remove the ESX hosts, so when you deploy the new vCenter and add the hosts, it'll be clean. Technically you don't, since it'll allow you to transfer management from one vCenter to another (I've done this personally), but it's best to remove.

To remove an ESX(i) host from vCenter, you do NOT need to put the host into maintenance mode. Just right click and disconnect and then do a remove. If you for whatever reason have your 'remove' grayed out, just drag your hosts into a dummy cluster and then remove the cluster which will then remove the host. Once you get your vCenter up, just add your hosts and you're back in business, no need to take down any VMs.

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William Lam

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[Rammi]

If you are going for a fresh install of VC then you need not worry about removing the hosts from the cluster.All the inventory information for VC is stored in the VC database. so when you are installing vCenter server 4 you should point to the old database and your inventory information should be available.

[vmetc_rich]

Looks like the vGhetto master beat me to it, but you can always right click the host and "disconnect" from the Cluster. Once disconnected right click the host again and choose remove. That way the guest remain operational. Add the hosts back whenever and wherever when you are ready.

[khughes]

Thanks guys, sorry for the late response. I thought that is what I could do but with my boss and director there, I would've never heard the end of it if I did something like that and had all the hosts go offline and all the VM's going down. I ran out of time before the first response I just ended up removing the cluster (since we only run 4 hosts) which did the same thing. Upgrade to vCenter 4 went well so +1 for me and I guess +1 for everyone that helped

Thanks for the help

Kyle