* Jan Stary <hans@stare.cz> [091125 04:18]:
quoted text > Scenario: 4.5/i386, dumping filesystems as follows (via daily.local):
> level 0 dump on Monday, level 1 dump on Tuesday, etc, level 6 dump on Saturday.
> Then level 0 again on Monday, and erase the old level>0 dumps.
>
> Now, I changed one of the dumped filesystems in the following way:
>
> > --- /var/backups/disklabel.sd0.current Mon May 25 08:14:43 2009
> > +++ /var/backups/disklabel.sd0 Wed Nov 25 08:10:09 2009
> > @@ -25,5 +25,4 @@
> > c: 625142448 0 unused
> > d: 20980890 1060290 4.2BSD 2048 16384 1
> > e: 41945715 22041180 4.2BSD 2048 16384 1
> > - f: 251674290 63986895 4.2BSD 2048 16384 1
> > - g: 309476160 315661185 4.2BSD 2048 16384 1
> > + f: 561150450 63986895 4.2BSD 2048 16384 1
>
> That is, what used to be two separate filesystems (sd0f and sd0g)
> is now sd0f (one filesystem the size of the sum). I restored the
> original content of sd0f on the (now bigger) sd0f partition from
> a level 0 dump. (sd0g was moved elsewhere, and is sd1a now.)
>
> Now, when dumping /dev/sd0f during the next daily dump,
> which happens to be a level 2 dump, the _whole_ filesystem
> seems to get dumped (as if it were level 0).
>
> I just want to make sure this is to be expected: dump just dumps
> everything that changed from the last lower-level dump, which happens
> to be everything, _because_ the whole filesystem was re-created.
> Right? I don't suppose "dump ; newfs ; restore" preserves inode
> numbers for instance, so every single inode has 'changed', right?
>
Yes, the behavior you're seeing is by design.
quoted text > Is there something I can do (dumpdates?) to be able to "dump | restore"
> and not 'break' the incremental dump cycle, or should I just schedule
> any future "dump | restore" with my level 0 dump day?
>
No, I don't believe there is anything you can do to change this outcome.
quoted text > Thanks for your time
>
> Jan
>
Take a look at
http://www.openbsd.org/cgi-bin/cvsweb/src/sbin/dump/traverse.c
and note how dump walks your filesystem and detects change. In
particular, the mapfiles routine.
HTH,
jim
