He used a usb CD drive, and a installed FreeNAS from the CD to the USB drive. Has the boot order usb, HD in bios.
stfn, Why are you wanting to run FreeNAS on a 4500.

Yes it's a standard 1U computer, but what a waste. At least for now. I will be a good option later on, when adaptec goes out business, after pissing all of the customer off.
Do something useful, figure out how to install FreeNAS on a 4000, 4100.