From: Ade Barkah <mbarkah@hemi.com>
Message-Id: <199512132215.PAA23386@hemi.com>
Subject: Anyway to get tape head past end of tape mark ?
To: hackers@freebsd.org
Date: Wed, 13 Dec 1995 15:15:12 -0700 (MST)
Content-Type: text
Sender: owner-hackers@freebsd.org
Precedence: bulk

Hello,

Uhm, I managed to get an end of tape mark to be written at the
very beginning of one tape. I don't know much about tapes, but
I think that means there are two filemarks written there now.

Q: how can I recover from this ?

The tape is a Wangtek 5150es (SCSI), attached to a FreeBSD 2.0.5
machine. I'm wondering several questions:

1. Is EOT really signified by two filemarks ?

2. Is this behaviour hardware or software ? That is, can software
   force the tape to go pass the EOT ?

3. If it's software, can I simply use the tape's MTFSF ioctl to
   skip over the two filemarks, or do I need to modify the driver ?

4. If it's hardware, can I cut a few feet at the beginning of the
   tape (hopefully past the EOT mark) and recover that way ? How
   much of the tape should I cut ? Can I maybe do a 'cat /dev/nrst0 >
   /dev/null' to force the tape to get to the EOT, eject without
   rewinding, then cut just past that ?

Thanks in advance for any help,

-Ade Barkah
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