I have Ubuntu 10.04 running on a MacBook Pro 5.5. It's using rEFIt to allow Ubuntu to boot via GRUB despite the Mac's EFI. For backup purposes, I'd like to clone it's hard drive using Clonezilla. I followed the instructions from the official Clonezilla website to create a live USB using the Clonezilla ISO and Tuxboot, however booting the Mac while the live USB is attached has no effect. Holding down the Option key during booting shows no additional drives, and bringing up the rEFIt screens also shows only the Ubuntu partition, and the original Mac OS X partition.
How do I make a live Clonezilla media that's bootable from a Mac running Linux?