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From: "Tony Battersby" <tonyb@cybernetics.com>
To: 'ael' <law_ence.dev@ntlworld.com>
Cc: linux-scsi@vger.kernel.org
Subject: RE: st.c block limits
Date: Thu, 1 Aug 2002 09:14:55 -0400	[thread overview]
Message-ID: <002001c2395d$6e842150$e0019d89@cybernetics.com> (raw)
In-Reply-To: <3D491F96.5040604@ntlworld.com>

> >># tar -cf /dev/ntape blah_home.tar.bz2; mt  tell

> The tape has a real 10GB capacity. (I believe.)  The 20BG
> blocks is correct
> for the default block size of 512. So compression is not an
> issue here. And
> the report above is actually 17.8/2 = 8.9 GB :-(

Some compression algorithms will actually expand data by a significant
amount.  For example, many implementations of ALDC compression will give a
compression ratio of 0.8 on random data.  In your example above you are
writing a .bz2 file (which is already compressed), so it would probably
expand if compressed again.  Try turning drive internal compression off:

mt -f /dev/ntape compression off

This might help squeeze a little more data on your tape.

Anthony Battersby
Cybernetics


  reply	other threads:[~2002-08-01 13:14 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-07-30 20:20 st.c block limits ael
2002-08-01  4:45 ` Kai Makisara
2002-08-01 11:46   ` ael
2002-08-01 13:14     ` Tony Battersby [this message]
2002-08-01 15:49       ` Rogier Wolff
2002-08-01 22:51       ` ael
2002-08-01 11:57   ` ael
  -- strict thread matches above, loose matches on Subject: below --
2002-08-01 16:06 Bryan Henderson
2002-08-01 16:53 Bryan Henderson

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