bin/106973: 'tar' cannot read own tape, but 'pax' can

[mjacob at FreeBSD.org]

The following reply was made to PR bin/106973; it has been noted by GNATS.

From: mjacob at FreeBSD.org
To: Bernd Luevelsmeyer <bdluevel at heitec.net>
Cc: mjacob at FreeBSD.org, FreeBSD-gnats-submit at FreeBSD.org,
        freebsd-bugs at FreeBSD.org
Subject: Re: bin/106973: 'tar' cannot read own tape, but 'pax' can
Date: Thu, 21 Dec 2006 11:48:02 -0800 (PST)

 I'm on vacation at present, but trying to follow this. This particular 
 tape drive is unfamiliar to me. I would assume that it must be some kind 
 of fixed blocksize device.
 
 Despite what you said, could you please try:
 
 mt -f /dev/sa0 seteotmodel 1
 cd /usr/include
 tar cvfb /dev/sa0 1 . || tar tvfb /dev/sa0 1
 mt -f /dev/sa0 rewind
 tar cvfb /dev/sa0 2 . || tar tvfb /dev/sa0 2
 
 > mjacob at freebsd.org wrote:
 >>
 >> Try using tar with a specified blocksize that's equal to the underlying
 >> h/w blocksize on the tape.
 >
 > The tape's blocksize is 10 KB, which is tar's default anyway. I tried
 > various other blocksizes nevertheless, to no avail; except an error in
 > dmesg ("(sa0:ahc0:0:4:0): 10240-byte tape record bigger than supplied
 > buffer") for small blocksizes.
 >
 > Greetings,
 > 	Bernd
 >