>A level 1 dump does backup of everything that changed since last level
>0 dump. Level 2 does all since last level 1 and so on.
Strictly speaking, that's not quite right (although in practice it's
usually good enough).
A backup at level N is everything that has changed since the most recent
backup less than N. You could set up a schedule (although not in Amanda)
of 0, 3, 5, 7, 9 and the 5 would be everything since the 3, for instance.
It's also fairly common to set up what's called a "Tower of Hanoi"
schedule (again, not in Amanda):
level 0 dumps everything
level 3 dumps everything since the 0
level 2 dumps everything since the 0
level 5 dumps everything since the 2 (levels 2 and 3 are less than
5, but 2 is the most recent)
level 4 dumps everything since the 2
level 7 dumps everything since the 4
level 6 dumps everything since the 4
The advantage to this schedule is that you need at most four tapes for
a restore no matter where you are in the cycle.
Amanda does better than this by not bumping level numbers until it would
gain anything. On a partition where things are very static, you might
do a level 1 over and over until the cycle went back to the level 0,
thus only needing at most two tapes to do a restore.
>Jens Bech Madsen
John R. Jackson, Technical Software Specialist, [EMAIL PROTECTED]
