On Wed, Apr 21, 2004 at 10:03:24AM +0200, Nicolas Ecarnot wrote:
> Level n backup is a backup where you save what has changed since the 
> last level n backup. period.

Minor correction:  A level N backup saves all files that have changed
since the last level N-1 backup.  Level 0 gets everything, since there
are no level -1s.

The practical effect of this is that restoring will require at most one
tape more than the highest-level backup that has been run.  (e.g., If a
DLE gets up to level 3 (the highest I've seen here), restoring it will
require, at most, 4 tapes (one each of L0, L1, L2, and L3) regardless
of the dumpcycle or how many tapes of each level have been run.)