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From: pwolfe@kailand.kai.com (Patrick Wolfe)
Newsgroups: comp.sys.sgi
Subject: Re: Network backup suggesstions?
Message-ID: <8912291517.AA02333@kailand.kai.com>
Date: 29 Dec 89 15:17:01 GMT
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Organization: Kuck and Associates, 1906 Fox Drive, Champaign IL USA 61820, voice 217-356-2288, fax 217-356-5199
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> From: Kian-Tat Lim <ktl@csvax.caltech.edu>
> Subject: Network backup suggestions?
>
>	We have a 95% full 500 megabyte filesystem on our 4D/240 that
> we would (very much) like to backup regularly.  The Iris only has a
> cartridge tape drive, but another of our machines (running a fairly
> standard 4.3 BSD) has a 6250 bpi 9 track.  The two machines are
> connected by a lightly-loaded Ethernet.
>
> 1)	The filesystem is NFS mounted on the BSD machine.  We would
> thus be able to use dump if we enabled root access to the remote
> filesystem.  Are there any additional security holes we would
> introduce by doing this?

If at all possible, try to forget about backing up with NFS access.  NFS is
fine for normal file access, but for really I/O intensive programs that access
lots of files (like backups), it's way too slow, and bogs down both machines.

> 4)	Any other suggestions?

Try GNU tar.  You can pick it up via anonymous ftp from expo.lcs.mit.edu
(something like /pub/gnu/tar1.07.Z).  It uses the /etc/rmt program (same as
BSD's rdump), allowing your IRIS to access a tape drive on a BSD machine.  It
also includes the rmt program, so you can access the IRIS cartridge tape from a
remote machine.  You need no special priviledges to compile and use it.

There are all kinds of options in GNU tar that make it an effective tool for
backups.  I use it on all of our System V machines (including two Iris 4D's)
for monthly full backups, dumping across our network to the 2.3 Gb 8mm
cartridge tape drive installed on a BSD 4.3 machine.  I also use it for daily
incremental backups on the BSD machines.

If you have trouble compiling it, check the options in the "port.c" file.

One other (beneficial, I think) side effect of GNU tar over regular AT&T tar.
On BSD systems, if you extract files from a tar archive, you become the owner
of all the new files (unless you are root).  On System V, AT&T tar restores the
original owner (because you are allowed to give away files), in which case you
may not have access to the new files (especially if the tar archive came on mag
tape from another site).  GNU tar doesn't restore the original owner, unless
you are root, so it acts just like BSD's tar from the user's standpoint.


-- 

        Patrick Wolfe	(pwolfe@kai.com, ...!kailand!pwolfe)
        System Manager, Kuck & Associates