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To: Justin Piszcz <jpiszcz@lucidpixels.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Tape Drive Question (2.6.14.4) 
From: corbet@lwn.net (Jonathan Corbet)
In-reply-to: Your message of "Sat, 24 Dec 2005 10:10:27 EST."
             <Pine.LNX.4.64.0512241009230.2904@p34> 
Date: Sat, 24 Dec 2005 11:54:58 -0700
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> $ ls -l /dev/st0*
> crw-rw-rw-  1 root tape 9,  0 2004-09-18 07:51 /dev/st0
> crw-rw-rw-  1 root tape 9, 96 2004-09-18 07:51 /dev/st0a
> crw-rw-rw-  1 root tape 9, 32 2004-09-18 07:51 /dev/st0l
> crw-rw-rw-  1 root tape 9, 64 2004-09-18 07:51 /dev/st0m
> 
> What differentiates st0 from a,l,m?
> What does writing or reading to a tape using a,l,m signify?

By default, they're all the same.  You can tweak the driver parameters,
however, to cause the different devices to use different densities and
blocking modes.  See mt(1) and Documentation/scsi/st.txt.

jon

Jonathan Corbet
Executive editor, LWN.net
corbet@lwn.net