can't mount root from dell x300 mediabase usb cd drive using latest iso

["Bob Bagwill" <bob@xxxxxxxxxxxxxxx>]

I was able to boot from the cd drive in my Dell X300 MediaBase, but after
the initial boot, it wasn't able to mount root from the cd, probably
because it's a usb cd drive.  Any suggestions for the appropriate argument
to mountroot> ?  Thanks.

--
Bob Bagwill