Path: utzoo!attcan!uunet!mailrus!uwm.edu!ogicse!decwrl!ucbvax!hplabs!hpfcso!hpldola!paul
From: paul@hpldola.HP.COM (Paul Bame)
Newsgroups: comp.sys.hp
Subject: Re: Reading past end-of-tape mark on cartridge tape?
Message-ID: <11870010@hpldola.HP.COM>
Date: 2 Mar 90 01:37:27 GMT
References: <483@limbo.Intuitive.Com>
Organization: HP Elec. Design Div. -ColoSpgs
Lines: 59

Hi Dave!

There are two questions here:

	1) What does the image tape contain (HP-UX filesystem?)
	2) How was the tape written (stated as unknown)

I'll assume image was probably made with either the built-in "switch backup"
or using dd(1) or an equivalent program maybe on Pascal Workstation.

To find out what the image tape contains, remember that most HP stuff
produces LIF volumes - even HPUX looks like a LIF volume.  Here's what I
find out by using 'lifls' on my 7.0 root disc:

	# lifls -l /dev/root
	volume BOOT data size 20 directory size 1
	filename   type   start   size     implement  created
	===============================================================
	SYSHPUX    -5822  3       20       ffff0800   00/00/00 00:00:00
	SYSDEBUG   -5822  3       20       ffff0800   00/00/00 00:00:00
	SYSBCKUP   -5822  3       20       ffff0800   00/00/00 00:00:00

You can try this on your tape.  If it resembles this you have an HP-UX image
of some vintage.  If 'lifls' finds nothing, you've probably got a tape
written with some other method like tcio and you can disregard the rest
of this.

If it contains a relatively recent (HFS) HP-UX file system image, you can
probably mount(1M) the tape as a disc.  This is slow and tortures your tape
drive - you'll need a *block* CS80 device for the tape drive in order to
mount it.  To remove all the oxide on the tape and ruin your tape drive, run
'fsck /dev/rct'.  To save this wear and tear you can copy to a disc.  It has
to be a *SPARE* disc at least as big as a 7912 - this'll obliterate it!

	$ dd bs=something-big if=/dev/rct of=/dev/sparedisc

This'll take a while but is dumber than tcio and does the right thing
with true image backups (not made with tcio).  Then you can 'lifls' the disc
just as you did the tape and/or mount the disc (you might want to try
fsck(1M) first however).

If it is an older BFS-format file system you'll get to explore the bfs*(1)
utilities - but the 'dd' is still what you want.

If it's a LIF disc from a BASIC or PASCAL workstation, the lif*(1)
utilities are all you need - and may even be tolerably fast just
on the tape without restoring it to disc.

If you haven't got a disc you can completely obliterate, cry out and
I'll suggest some other ideas - this is getting long.

	-Paul Bame

#define DISCLAIMER These do not represent the official opinions, policies, \
		   or suggestions of Hewlett-Packard.  Use at your own risk.

P.S.  Back up everything - just in case.
P.P.S.  I skipped lots of things I just *assume* Dave knows - don't try this
at home!