Path: utzoo!attcan!uunet!fernwood!apple!usc!cs.utexas.edu!asuvax!mcdphx!fishpond!fnf
From: fnf@fishpond.UUCP (Fred Fish)
Newsgroups: comp.unix.wizards
Subject: Re: Accidentily messed up tar tape...
Message-ID: <110@fishpond.UUCP>
Date: 25 May 90 04:12:06 GMT
References: <5368@hub.ucsb.edu>
Reply-To: fnf@fishpond.UUCP (Fred Fish)
Distribution: comp
Organization: Amiga Library Services
Lines: 31

In article <5368@hub.ucsb.edu> jim@piggy.ucsb.edu (Oreo Cat) writes:
>                                   I backed up a bunch of files onto a
>1/4" tape, and deleted them from the disk.  Unfortunately I did not write
>protect the tape after I wrote the files.  Later I discovered that I needed
>a few files off of the tape, but instead of saying "tar xvf /dev/rst0 file1
>file2 ..." I said "tar cvf /dev/rst0 file1 file2 ...".  The files I listed
>did not exist, but tar went ahead and put an empty tar file on the tape.

This sort of tale of woe appears about once every 4-6 months on the net
and the general flurry of knowledgeable replies explain that for the current
crop of 1/4" tapes, there is NOTHING you can do with a stock tape drive
to recover the data.  The problem with recovery exists at the hardware
level within the drive itself.  It refuses to read past a written EOT, and
it also erases across the full width of the tape as it writes the first
track.

If I am mistaken, someone who has successfully recovered from this situation
using a stock 1/4" tape drive please send me the details of how you did
it.  If anyone has written up a long description of the details of why
recovery is impossible, I'd also appreciate receiving a copy.

Naturally, you should be able to recover at least part of your data
using special hardware and software techniques.  There are companies
that specialize in this sort of thing, though I don't have any names
or addresses quickly available (they are back at the office).

-Fred

 -- 
# Fred Fish, 1835 E. Belmont Drive, Tempe, AZ 85284,  USA
# 1-602-491-0048               asuvax!mcdphx!fishpond!fnf