I found the following blog article particularly useful in documenting the steps to upgrade an ESXi 4.0 server to 4.1.
I’d already downloaded upgrade-from-ESXi4.0-to-4.1.0-0.0.260247-release.zip to my vCenter server. I’d also downloaded and installed VCLI 4.1 on the vCenter server too from here. The following applicable steps in the article above.
- Power off your VM’s and put the host into maintenance mode
- Change your current directory to C:\Program Files\VMware\VMware vSphere CLI\bin
- From the vSphere CLI prompt
- vihostupdate.pl –server host name or IP address -i -b location of the ESXi upgrade ZIP bundle -B ESXi410-GA
- So in my case (don’t forget the .pl in vihostupdate.pl)C:\Program Files (x86)\VMware\VMware vSphere CLI\bin>vihostupdate.pl –server esxiblade2 -i -b d:upgrade-from-ESXi4.0-to-4.1.0-0.0.260247-release.zip -B ESXi410-GA
After rebooting the ESXi server it was then running at ESXi 4.1 !