Ubuntu :: Creating Really Big Volumes & Backups?

First Question: I have a very big volume (20+TB). When I try formatting it as ext4, I get the error message:

mke2fs 1.41.12 (17-May-2010) mkfs.ext4: Size of device /dev/sdc1 too big to be expressed in 32 bits using a blocksize of 4096. I understand that ext4 has a limit of 1EB (about a million terabytes), but a 32-bit limitation in e2fsprogs prevents me from creating a partition > 16TB.

Until e2fsprogs is updated to use 48-bit block addressing, it appears my choices are:Break up the volume into smaller volumes < 16TB, or Use xfs or zfs (I have already created a test xfs partition, and it works fine).

Does anyone have any opinions about which option is preferable? I have never used xfs before. Is it as robust as ext4? Is it as well supported by Ubuntu? What about zfs? Is it worth downloading from the ppa?

Second Question: I now have a huge amount of data to back up. In the old days, I remember making a full backup of a "big" 10 MB hard drive by taking a stack of floppies and inserting them one at a time into my floppy drive while my backup program split the backup into 1.4 MB chunks small enough to fit on a floppy.

I now have the same problem, but at a different scale. I need to back up 20+TB onto a stack of external 2TB drives. Is there any software package that can fragment a backup in this way?