Expanding slice

Hi all
I am testing backupPC as a backup solution for machines, as far as i knew, backuppc cannot combine more than storage from different slices so it have to be in one slice my question is, what is the easy way to offer a virtual logical drive expanded/expandable to backuppc, i mean i want to assign a backup location to backuppc and i can extend it later with more disks,i am using ubuntu server, what do you recommend?

sounds like a job for the lvm (logical volume manager).