I have a Western Digital MyBook Home Edition USB2/FW/eSATA 1TB drive http://www.amazon.com/gp/product/B000WBJDUA
attached to my Ubuntu 9.10 workstation. This drive is formatted FAT32 so I can easily share files between Linux/OSX/Windows machines, although it's usually just attached to my linux box.
I recently bought an identical drive to back up the first drive. I was planning to format the second drive FAT32, hook it up to the Ubuntu workstation, then use rsnapshot to mirror the first drive.
This is the first time I've tried something like this. Before I do this, I thought I'd post a message here to see if there is a better way to set up redundancy. Let me know if you think I should be backing up the first drive some other way. Thanks.