Joshua Baker-LePain <jlb17 AT duke DOT edu> writes:

> From 'man dump':
>
>        -level#
>               The dump level (any integer). A level 0, full backup, guaran-
>               tees  the  entire  file  system  is copied (but see also the -h
>               option below). A level  number  above  0,  incremental backup,
>               tells  dump  to  copy  all files new or modified since the last
>               dump of a lower level. The default  level  is  9.  Historically
>               only levels 0 to 9 were usable in dump, this version is able to
>               understand any integer as a dump level.
>
> IOW, a level 2 only grabs stuff that has changed since the last level 1.

I think if you do

0 1 0 2

then the level 2 will dump things changed since the second 0.

FWIW, the NetBSD man page is similar:

     -0-9    Dump levels.  A level 0, full backup, guarantees the entire file
             system is copied (but see also the -h option below).  A level
             number above 0, incremental backup, tells dump to copy all files
             new or modified since the last dump of a lower level.  The
             default level is 9.

It's amusing that someone wanted to extend past 9.  I've only ever
seen 3 or maybe 4 in real use.



-- 
    Greg Troxel <gdt AT ir.bbn DOT com>