info needed on file archive software and DAT tapes

[Bill Johnston [csr]]

Unix-Wizards;
I am looking for file archive software, or pieces that I might
start from to make an archive system. What I want to do is more or less
the following:

Have a user cmd (archive) that marks a file as a candidate for archiving.
	``mark'' probably means make an entry in an archive DB file
	somewhere that do_archive reads.

Have a (probably cron run) command (do_archive) that checks the archive
DB for archivable files, writes those files to tape, and keeps track of
where they were put (updates the archive DB).
	``keeping track'' of where they were put means what tape, and
	where on the tape. This is somewhat tricky as it means a labled
	tape format (though the label could be a text string in the
	first file of the tape). It would be nice if the main part of the
	tape format were standard (e.g. tar).

Have a recover cmd (that uses the archive DB information written by
do_archive) to retrieve files without the user having to know what
tape, and what file on the tape has the (tar) archive containing the
required image file.
	The ``real'' file name (as kept in the archive DB) might be
	something like a full path name, but an alias mechanism would
	also be nice.

At the least I have seen potentially useful ``pieces'' pass by on the
source archives over the years: seems that there was a version of
dump that records files deleted since last dump (if I remember
correctly), and I seem to remember an ``incremental'' tar of some
sort. Pointers to these would be appreciated.

On a related topic, we are archiving images, and I am seriously
considering DAT instead of Exabyte type video format tape. The reason for
this is that I understand that access is much faster for DAT, and we
may be shuffling files off of and on to tape frequently.

Anyone have any experience with the DAT drives, software, etc? Any
problem with skipping to the end of previously written tape and adding
files?  (We will probably have several of these drives on Sun
SpacrStations.)


I do not normally read this list, so send comments directly to me if
you can:
	Internet: wejohnston at lbl.gov
	uucp probably is: .....ucbvax!csam.lbl.gov!johnston


	Thanks,

	Bill Johnston
	Human Genome Center
	Lawrence Berkeley Laboratory