[dnanian]

Well, in general, you need a 1:1 relationship of source volume to destination. You can partition a particular backup drive to accomodate multiple source volumes, of course.

I wouldn't back up onto something you're already using for something (e.g. your Big Disk) -- you want some physical redundancy.

You can also rotate multiple backups to get yourself some redundancy (see the Introduction to the User's Guide).

Does tha thelp?