Updating ESX hosts to 4.1 before updating vCenter from 4.0 to 4.1

[Anfernee86]

Does anyone see a problem updating my ESX hosts to 4.1 and leaving them in the old vCenter 4 Update 1 cluster? I rebuilt a new vCenter 4.1 server but can't shut the VMs down and put the ESX hosts all in maintenance mode until tomorrow night. I would like to put the ESX hosts in maintenance mode one at a time in the old vCenter server and update to 4.1 and then move remove/add into new vCenter tomorrow night.

[Troy_Clavell · Accepted solution]

you can't manage an ESXi4.1 host with anything less than vCenter4.1. So your plan will not work. You need to upgrade vCenter first.

http://www.vmware.com/pdf/vsphere4/r40/vsp_compatibility_matrix.pdf

[DSTAVERT]

Create a new cluster in the 4.1 vCenter. Delete the hosts from the old cluster and add them to the new cluster. No shutdown required. You can manage the 4.0 hosts in vCenter 4.1 but not the reverse.

[Anfernee86]

I can't Remove the host without going into Maintenance Mode which means I need to shut all the vm's down, correct? There lies my problem because I don't have enough resources to juggle running vm's on old ESX 4.0 hosts while I update the others. I will just shut down all vm's tonight.

[Troy_Clavell]

right click on the host, choose disconnect, then remove. In the new instance choose add host. This will allow all your guest to continue to run as normal.

Once all hosts have been added to the cluster, enable HA/DRS.

[Anfernee86]

Thanks for the reply. Unfortunately, it is an EVC cluster so no luck. I need to shut everything down.