vCenter service fails to start after 4.0 to 4.1 upgrade with Event ID: 1000

I ran into an small issue while upgrading an environment’s vCenter 4.0 to 4.1 that I thought was worth mentioning. As I got to the end of the vCenter 4.0 to 4.1 upgrade (see this post for more information: http://terenceluk.blogspot.com/2010/11/upgrading-vmware-vcenter-40-to-41.html), I noticed that the service would fail to start:

[INFO] vCenter Server DB Server type: Custom

[INFO] vCenter Server DB Server type: Custom

[INFO] vCenter Server License path: 27000@vcs01.domain.com

[INFO] vCenter Server License path: 27000@vcs01.domain.com

[INFO] Launching installer with backed up install data configuration

[INFO] Starting vCenter Server...

[ERROR] Error: vCenter Server service failed to start

[ERROR] Exiting…

Reviewing the Windows event logs, I found an Event ID: 1000 logged:

The description for Event ID 1000 from source VMware VirtualCenter Server cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.

If the event originated on another computer, the display information had to be saved with the event.

The following information was included with the event:

Unable to get exclusive access to VC repository. Please check if another VirtualCenter instance is running against the same database schema.

the message resource is present but the message is not found in the string/message table

The event error was pretty self explanatory so I went ahead and logged onto the old vCenter 4.0 to stop the service. What I found interesting was that I performed the full update without stopping the service and did not get any complaints when the process went ahead to upgrade the database. Once I stopped the old vCenter database and re-ran the upgrade, the services started without an issue.

Lesson learned? I obviously missed the line in the instructions of the deployment guide but I suppose I did learn something out of this (aside from being more careful when reading instructions).