From: pjs@euclid.JPL.NASA.GOV (Peter J. Scott)
Subject: Archival packages for Unix redux
Followup-To: comp.sys.sun
Reply-To: pjs@euclid.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, NASA/Caltech
Date: Wed, 15 Apr 1992 16:18:09 GMT

I posted a while back asking for info on archive programs for Unix,
and got a couple of bites, from AT&T for their CommVault product, and
Advanced Software Concepts for NetArchive.

These products are similar, unfortunately they don't do what I said
I needed!  They're very good products, I'm sure: they work by
sending files to an optical jukebox or DAT according to some
flexible heuristic, and leaving behind stub files of the same name
which trigger a retrieval when accessed.  Difficult stuff to do, I'm
sure they worked hard at it.

However, this doesn't work for us for several reasons: (1) the archival
files still have to be on-line; we need to archive many gigabytes,
we can't keep adding jukeboxes for that, we need to maintain a library
of 8mm archive tapes.  (2) the users frequently create files of the same
name in the same place later on, thus destroying the stub of the earlier
version which they might need to retrieve.  (3) the users need to be able
to archive files manually, with a simple command, and this operation is
complicated in these two products.

I must not have been clear enough in my original posting.  Let me put
it differently.  We are looking for something which we expect will have
user commands of the form:

arcput <filespec> [<tag>] [<comment string>] - archive a file, or group
of files (recursively if specified), and associate an optional tag and comment.
The files are immediately copied and then the user can do anything they like
with the originals.

arcdir <filespec> [<options>] - list the files in the archive that match the 
spec.  <options> are optional combinations of date, tag, comment strings
to match, perhaps containing wildcards, and combined with boolean operators
much like the options for the "find" utility.

arcget <filespec> [<destination> [<options>]] - restore the specified files,
select according to the same option syntax as arcdir, and put in a different
location if specified.

I imagine that "arcput" would copy the files to a buffer on disk, and then
put them off to tape when it has the chance.  I'm sure there are objections
to the command semantics I've outlined, this is just off the top of my head
but I'm also sure this is not so hard to implement.  I did something like
it on VAX/VMS (in DCL, no less) and I could do the same for Unix, but I'd
much rather buy something that already does it properly.  (We'd also like
a GUI interface; we want to make things as easy as possible for our users.)
The VMS system maintained a log on disk of the files that were stored on
tape and used these as the database for the "arcdir" and "arcget" commands.
A restore operation started a batch job that printed a message on the operator
console saying which archive tape needed to be mounted.  Something similar
is certainly possible for Unix.

I can't believe that we are the only people with this kind of requirement.
Tar, even GNU tar, does not fit the bill - our users are busy with their
own work (which frequently involves creating multi-gigabyte files) and
shouldn't be bothered with tape administration.  Is there no product
anywhere which does what we want (and does it on Sun 4s and HP 700s)?

-- 
This is news.  This is your       |    Peter Scott, NASA/JPL/Caltech
brain on news.  Any questions?    |    (pjs@euclid.jpl.nasa.gov)


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