X-Recipient: archive-cygwin AT delorie DOT com
X-Spam-Check-By: sourceware.org
Date: Wed, 21 Oct 2009 12:59:14 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: Quantum LTO 4 tape drive and Cygwin 1.7?
Message-ID: <20091021105914.GG16678@calimero.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <4ADE1C79 DOT 1090701 AT RevolutionONE DOT com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4ADE1C79.1090701@RevolutionONE.com>
User-Agent: Mutt/1.5.17 (2007-11-01)
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Precedence: bulk
List-Id: <cygwin.cygwin.com>
List-Unsubscribe: <mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com

On Oct 20 15:24, Jeffrey C. Smith wrote:
> I'm trying to use tar from Cygwin 1.7 Beta on a Win 2008 R2 machine to 
> backup some files to a Quantum LTO 4 SAS tape drive. I've tried all the 
> usual POSIX paths (/dev/nst0, /dev/st0, /dev/st1, etc.) as well as some 
> other variants (\\.\tape0) with no joy. tar fails with a "No such file or 
> directory" error.

The right way to access tapes is to use the /dev/stX or /dev/nstX
variation.  Using the Windows path \\.\tapeX will not work as expected.

Typically the first tape drive attached to a Windows machine is
called "tape0", which is what Cygwin tries to access when specifying
/dev/st0 and /dev/nst0.

If you want to see the name of the tape drive on your system, just open
the Device Manager and then open the device tree element "Tape drives".
You should find an entry named like your tape device, for instance
"QUANTUM ULTRIUM 4" or something along these lines.  Double click opens
the Properties dialog.  There's a tab called "Tape Symbolic Name".  Open
it.  It will show you the string "tapeX" with X some number >= 0.  THis
is the same number to use in Cygwin.

I just mounted a tape drive to my Windows 7 machine and it showed up as
\\.\tape0 in the device manager.  I could use mt(1) on it:

  $ mt -f /dev/nst0 status
  drive type = STK 9840
  drive status = 1107361792
  sense key error = 0
  residue count = 0
  file number = 0
  block number = 0
  Tape block size 65536 bytes. Density code 42 (unknown).
  General status bits on (410b0000):
   BOT ONLINE IM_REP_EN

Using the correct /dev/[n]stX, I never saw a "No such file" error yet.
What I can easily reproduce is a "Permission denied", though.  Under
UAC, if you're using the standard command line you don't have admin
privileges.  More exact, you don't have backup/restore privileges.
Accessing a tape drive without these privileges fails.  If you want
to access the tape drive, you have to start cygwin elevated.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple