I have a 1 Tb USB external hard drive which I want to use to backup data from my home and office desktops (both running Linux). Should I format the drive (possibly split into a few partitions) as vfat or ext3? I don't anticipate using the drive with Windows very often so this is not a primary concern. The main thing holding me back from just using ext3 is the problems you can have when two different users (home and work accounts) try to access each others data. Is there any way to mount an ext3 drive with user id mapping?