VMware ESX 3.5 & VirtualCenter 2.5 with Update 2

So for my first post I thought I would mention something I have found while working with ESX 3.5 and VirtualCenter 2.5. Recently I was at a customers site doing a VMware ESX installation. We had three ESX 3.5 Update 1 servers up and running all being managed by a VirtualCenter server running 2.5 Update 1.

So when demoing Update Manager we set one of the ESX servers to apply the critical updates by applying the baseline and then setting remediate to run 5 minutes in the future. So the customer looks on happily at how the ESX server puts itself into Maintenance Mode and migrates VM's off in preparation for patching and the subsequent reboot. The ESX host comes back up and all is well. That is until we rebooted the VirtualCenter server, this is when the VirtualCenter service decides that it will no longer start... the following error is in Event Viewer...

Event ID 7024 - The VMware VirtualCenter Server service terminated with service-specific error 2 (0x2)

So with some google'ing about I find the following thread on the VMware forums, http://communities.vmware.com/thread/122543;jsessionid=7A5139DFE94BA6A4AD870E08F442DF23?tstart=0&start=15

Although this post lists this situation now, it didn't at the time, and admittedly I did add this scenario to that post... The post was mentioning IIS and Converter Services being the issue, I had no IIS and and even when disabling Converter I had the same issue...

So after stepping back to think about what had changed recently, I realised that one of the three ESX servers was a higher build version than VirtualCenter. So I installed VirtualCenter 2.5 Update 2 to the VC server and rebooted... the VC server came back up, all services started without any complaints and we were running again.

Historically speaking, when working with ESX environments pre-Update Manager, VirtualCenter was always updated first, thanks to Jason Willey (http://www.virtuallycrazy.blogspot.com). As it makes complete sense that the management server is backwards compatible with older versions of ESX, but cannot know about new features or changes.

I am a fan of Update Manager for ESX, my main reason for posting this is to get the point across that it will make your lives easier as long as you remember to keep VirtualCenter updated too, and more importantly updated before the ESX servers.