confused about dump/restore levels

[Sergei G]

Hi,

I had to use my backup to restore the system and it generally worked.
However, I run into an issue that made me question if I understood dump
right.

On Feb 1 I had a level 0 backup of root file system.
On Feb 2 and Feb 3 I had level 2 backups of the same file system.

In all cases I used newfs prior to restore.

I then tried to restore (Case A):

Feb 1 Level 0, ok
Feb 3 Level 2, reported errors (don't error message; got prompt y/n, then
message with option to abort and report core dump)

I tried again (Case B):

Feb 1 Level 0, ok
Feb 2 Level 2, ok
Feb 3 Level 2, error: Incremental dump too high

So, I got my system restored, but I am confused why Feb 3 backup did not
restore in Case A.

It has nothing to do with corrupted files, because I had the same issue on
other file system and it worked the same way.