Re: [SLE] SCSI Tape compression

From: Ken Schneider (
Date: 08/09/05

  • Next message: Bruce Marshall: "Re: [SLE] SCSI Tape compression"
    Date: Tue, 09 Aug 2005 12:49:36 -0400

    On Tue, 2005-08-09 at 13:31 -0300, Sebastian Jeremias wrote:
    > Hi,
    > I'm having troubles compressing a DDS-4 tape. I have an HP C5683A drive,
    > and when I do 'mt -f /dev/nst0 status' (or mtst) I get:
    > twist:/opt/ltt # mtst -f /dev/nst0 status
    > SCSI 2 tape drive:
    > File number=0, block number=0, partition=0.
    > Tape block size 0 bytes. Density code 0x8c (EXB-8505 compressed).
    > Soft error count since last status=0
    > General status bits on (41010000):
    > The problem is that it's not using compression, although it's turned on.
    > My questions are:
    > - Is EXB-8505 the right compression mode? I read you could change it to
    > DDS-4, but what's the compression code for DDS-4?
    > - Do I need a hardware specific driver for the SCSI controller for the
    > O.S. to recognize the tape in the proper way?
    > - Something I'm missing?
    > Thanks in advance,
    > Sebastian
    Try this command instead:

    mt -f /dev/st0 datcompression

    to see the status of compression. Use mt -f /dev/st0 datcompression 2 to
    turn it on.

    Ken Schneider
    UNIX  since 1989, linux since 1994, SuSE  since 1998
     "The day Microsoft makes something that doesn't suck is probably
      the day they start making vacuum cleaners." -Ernst Jan Plugge
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  • Next message: Bruce Marshall: "Re: [SLE] SCSI Tape compression"