Dustin J. Mitchell wrote at 00:41 -0400 on Oct  3, 2008:
 > On Thu, Oct 2, 2008 at 9:03 PM, Aaron J. Grier <agrier AT poofygoof DOT com> 
 > wrote:
 > > I beg your pardon, but /sbin/dump is perfectly capable of dumping
 > > subdirectories on most unixes.  it just won't record (or read) the date
 > > of the dump in /etc/dumpdates.
 > 
 > I'm happy to be proven wrong (I've not used dump myself), but it was
 > my understanding that dump, in general, worked at the filesystem
 > level, against a block device.  For example, the OSX manpage (which is
 > just inherited from the BSD manpages) says:
 > 
 >      dump [-0123456789cnu] [-B records] [-b blocksize] [-d density]
 >           [-f file] [-h level] [-s feet] [-T date] filesystem
 > 
 > where the use of the term "filesystem" means, to my understanding, a
 > filesystem and not an arbitrary subdirectory.  Now, you may have a
 > filesystem mounted at /usr/local, in which case you can use dump to
 > back up /usr/local, but I don't think that's what you meant.
 > 
 > Can you point to some documentation to support your assertion?

This was touched on as part of a larger thread in April.

http://www.mail-archive.com/amanda-users AT amanda DOT org/msg40187.html

In short, some OS's support a dump with files, but it's not clear how
well that is supported (or will work at all) in amanda, particularly
with incremental dumps.

I think it'd be great if we could use the native filesystem's dump (or
dump-like) tool rather than gtar.  Then you can backup filesystem
specific attributes that gtar may not handle.  (and you don't touch
atime, which has always been an annoying quibble with having to use
tar).  Having to dump the whole filesystem, of course, is really the
big hurdle with using a dump or dump-like tool.