[SLE] SCSI Tape compression

From: Sebastian Jeremias (ljeremias_at_lightech.com.ar)
Date: 08/09/05

  • Next message: James Wright: "Re: [SLE] Problem using xCHM"
    Date: Tue, 09 Aug 2005 13:31:56 -0300
    To: suse-linux-e@suse.com
    
    

    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):
    BOT ONLINE IM_REP_EN

    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

    -- 
    Sebastian Jeremias
    Ingenieria
    LIGHTECH
    +54 11 4311.9888
    http://www.lightech.biz
    -- 
    Check the headers for your unsubscription address
    For additional commands send e-mail to suse-linux-e-help@suse.com
    Also check the archives at http://lists.suse.com
    Please read the FAQs: suse-linux-e-faq@suse.com
    

  • Next message: James Wright: "Re: [SLE] Problem using xCHM"

    Relevant Pages

    • Re: DAT/DDS tape backups...
      ... >DDS-4 drive complete with a 8 tape cassette autoloader. ... >At least that is how the specifications for these drives (and all ... >With compression turned off, I get 19459MB to tape, with it on, I get ... Don't feed the hardware compressor already ...
      (Fedora)
    • Re: Reports for GB per hour to tape
      ... In addition to the overhead of software encryption, consider the effects of the loss of hardware compression for the data written to tape, which will affect both tape performance and thus elapsed time and the amount of tape used. ... For IBM-MAIN subscribe / signoff / archive access instructions, ...
      (bit.listserv.ibm-main)
    • Re: Why does measuring tape bend one way?
      ... > into tension and the edges into compression. ... > tape is thin compared to the length over which the compressive ... > slight curve with the energy released by the compressive force ... > moving as the deformation allows the force to move. ...
      (sci.physics)
    • Re: Adaptec 1542C with NT4
      ... Today I restored NTBackup from WinNT 3.1 and WinNT 3.5 installations. ... Backup made backups. ... Is it possible that the tape drive has been changed or had hardware ... hardware compression.) ...
      (comp.periphs.scsi)
    • Re: backup compress on the fly
      ... >>The point is that, if there is an error, all the CRCs in the ... > off the tape .. ... > there's an asumption that you only have 1 compressed file ... the "z" compression option specified, which results in a single tar ...
      (Debian-User)