vSphere 4.1u1 ESXi upgrade

[mtar]

Hi all, I need to upgrade a vi3 farm to vsphere 4.1u1 ESXi.

I will install a new virtual center so I won't migrate old one.

My problem is migrate without downtime (except of course for VMware tools and vHW which will be scheduled later during some nights after complete vSphere migration).

In my mind I would consider to disable HA and DRS on actual vi3 cluster, then disconnect and remove hosts from old virtual center.

Once done I would connect ESX vi3 servers on new virtual center 4.1, then I will start ESXi4.1u1 fresh install host by host moving VMs before in order to keep them up and running.

Is it possible ? Are there any warning or risk ?

Thanks in advance. Massimo.

[Troy_Clavell]

your plan will work. Just remember if you are going to manage VI3 hosts in vCenter 4.1 you will need to keep your VI3 license server running or build a standalone license server.  Once all hosts are vSphere4, you can down the license server.

[weinstein5]

A vcenter 4 can manage an ESX(i) 3 host - so you will be able to utilize vmotion to eveacuate a host and then upgrade it - here is VMware's upgrade  - http://www.vmware.com/pdf/vsphere4/r41/vsp_41_upgrade_guide.pdf

[MauroBonder · Accepted solution]

Without downtime, ok, did you have more than one host with resource to keep virtual machines running with DRS and HA ? or with supports to do VMotion  ?

You need basicly:

1- upgrade virtual center

2 - evacuate 1 host

3 - put in maintance mode

4 - do a fresh install on this host

5 - configure and add to vcenter

Check too http://www.vmware.com/pdf/vsphere4/r41/vsp_41_upgrade_guide.pdf

http://www.vmguru.nl/wordpress/2010/07/how-to-upgrade-to-vsphere-4-1/

good luck

Please, don't forget the awarding points for "helpful" and/or "correct" answers. 

Mauro Bonder - Moderator