I have a 12TB enclosure that's filled with data (ext3). I'd like to make a copy of it, spanned across individual 3TB disks, each of which is readable on its own (no RAID or bonding). Ideally, I'd like this process to spit out some index of which files are on which disk, but that's not strictly necessary. The end result must be readable files on the disk in the original directory structure, not an archive file. Splitting directories (duplicating the directory structure) across volumes is fine.
The 3TB disks are not all mounted at the same time (and not able to be), so I need something that will let me pause the copying to switch disks. I strongly prefer a solution that doesn't require me to figure out which files go on which disk or keep track of what's been copied.
Is there an existing package that will do this?