My policy is not to update to new releases until they have stabilized for a decent period of time.
Therefore, we have not yet performed our upgrade to Version 4.0 yet. We were waiting for the release of Update 1 before migrating the system to version 4.
I have been using ESX4 since the private Beta, but not on a production environment.
Over the upcoming period I will share with you the process of the upgrade from 3.5 to 4.1.
First off, I will not perform the upgrade until the latest release stabilizes a bit, and the "oversights" that have and will pop up - calm down. I actually find this a good sound idea,
But just to lay out the Migration Plan:
- Installation of a new vCenter - 4.1
- Migration of environment to the new vCenter (this will probably be the most lengthy part)
- Upgrade ESX Hosts 1 by 1
- Upgrade VM's to Virtual Hardware Version 7
- Project complete.
It may look simple - but when dealing with a production environment and with so many dependencies - nothing is that simple.
I hope that the sharing of my experiences will be able to help those in their journey through the virtual universe (and also as a by-product, document my stages for the future reference).