High Point says running the Rocket Raid 4222 card in ESXi is fully supported, but the steps provided in the documentation don’t work. Here is how to install the driver in a few easy steps.

First, the driver file they provide on their website does not work. You have to extract and modify the metadata.zip file, then extract the metadata xml file. The metadata files need to include version 4.1, but they only say version 4.0. Then you have to repackage them into the zip file and back into the main zip file. I have done this for you and you can download the working driver here. hpt 4222 ESXi 4.1 driver

2. The install steps are totally bogus. ESXi doesn’t even have the commands listed in the installation procedure in the High
Point instructions. Do this instead:
a. Run the Vsphere CLI program included with Vsphere 4.1 on your desktop machine (start> programs> etc)
b. Put the host in maintinance mode from vsphere client or at the host terminal.
c. Run the command “perl vihostupdate.pl -server [ip address] -username root -bundle hpt.zip -n
d. Take the host out of maintinance mode and reboot.

Hopefully you find this helpful.