Upgrade a single ESX1i 4.x host to a higher version by executing the following steps:
- On your laptop/pc install vSphere CLI
- Download an upgrade package like ESXi4.0-to-4.1.0-0.0.260247-release.zip
- Put the ESX host in maintenance mode.
- Open a MSDOS console on you laptop and goto C:\Program Files\VMware\VMware vSphere CLI\bin
- vihostupdate.pl –server 192.168.0.1 -i -b F:\upgrade-from-ESXi4.0-to-4.1.0-0.0.260247-release.zip
Enter username: root
Please wait patch installation is in progress …
The update completed successfully, but the system needs to be rebooted for the changes to be effective.
- Update your VI Client and login to the ESX server.
That' s it. I upgraded my free ESX version like this. You can also use vCenters host update utility.