Took a whole day yesterday to upgrade my test rig from VMware ESXi 3.5.5 to 4.1 (the new one that shipped a few days ago). As well as having to buy a new network card (I can recommend the Intel Pro 1000/GT – cost me just shy of 30 quid and works just fine), I had to go to 4.01 and then to 4.1. I’m sure there is a more elegant way to upgrade, but I couldn’t figure out what it was. Obviously if you have a vCenter Server, it’s a piece of piss, but if you’re tight like me and have the free standalone ESXi server, what do you do? This is what I did….

So, in a nutshell :-

– Download vSphere client 4.0 and the 3.5.5. -> 4.01 upgrade ZIP

– Install the vSphere client, ensuring to check the installation of the Host Update Utility (or whatever it’s called)

– Once installed, run the Host Update Utility, point it at your ESXi server and the update ZIP file

– This process took bleedin’ ages on my server – seemed to be stuck on 3% for about 20 minutes, but hang in there, it does complete! Took around 40 minutes, I think. Though I wasn’t counting…

– Install the vSphere CLI tool and run the vihostupdate.pl script from the CLI with the update 4.01 to 4.1 ZIP file. This process is much quicker and took but a few minutes.

– Don’t forget to update the vSphere client on your management workstation too.

– If at any point in the vSphere client install/uninstall tangle you get Visual J# errors, uninstall the current one from Control Panel and get the latest one from Microsoft. Even though it’s dated 2007, I think that’s the latest. Solved it for me, anyway.

All in all a whole day burned, but at least it’s done now!!