fpart
Sort files and pack them into partitions
... can then be used by third party programs.
Fpart also includes a live mode, which allows it to crawl very large filesystems
and produce partitions in live. Hooks are available to act on those partitions
(e.g. immediatly start a transfer using rsync(1)) without having to wait for
the filesystem traversal job to be finished. Used this way, fpart can be seen
as a powerful data migration tool.