I have tried to understand this thing however I just don't get it. Why do Unix people like to use this number sequence for backups?
3, 2, 5, 4, 7, 6, 9, 8, 9
From what I can see from reading the dump man page closely an incremental backup is based on the dumps LESS THAN the current level not less than and equal too. (If it was I could understand it, as the 3, 2 would force it to backup all files since the level 0 again rather than basing on the previous dump, however this is not the case).
Why don't people use?
2, 2, 3, 3, 4, 4, 6, 5, 6
The only reason I can think that it is of any use is when each "Number" is a tape, and it is trying to maximise the versions available on the tapes, not destroying the previous days backup before it has written the new one. However it does not say this in the any manual most people don't use tapes these days anyway... is it just a throw back to the old days of tape management?