Because:
1. The files may well not *fit* on the disk if they aren't sparse! Take a
couple sparse 2GB cores, which really take less than 100KB each, handled
properly...
2. The file might *have* to be sparse, otherwise it won't work (rather
uncommon, but it do exist).
> I would argue that dump can't deal with *ANY* file perfectly, since it
> (in the typical configuration) is committing the utter no-no of
> reading a non-quiescent r/w mounted filesystem from the raw block
> device.
At least it's *tries* to handle them, which is more than I would claim
tar/cpio et al tries to do :-) Yes, another approach would be better, but
there are lots of cases where tar/cpio isn't anywhere near enough.
There *are* reasons why commercial UNIX backup systems doesn't usually use
the 'read the raw-device' approach (one of them is the porting nightmare),
but on the other hand the one's I know of does handle sparse files, it's
really a necessity for serious backups.
Wonder what it would take to make Legato (Networker) or Spectra Logic
(Alexandria) to create a backup client for Linux. Both support SCO after
all. The best would be to get them to port the Server too, but that might
be considerably harder :-)
-- Torbjörn Lindgren E-mail: tl@funcom.com If Santa ever DID deliver presents on Christmas Eve, he's dead now.