dump compression and variable block sizes

From: Chris Cameron (chris_at_upnix.com)
Date: 10/26/04

  • Next message: Rik van Riel: "Re: BIND process size"
    To: redhat-list@redhat.com
    Date: Tue, 26 Oct 2004 11:44:15 -0600
    
    

    Gist of the problem is I'm trying to use dump's compression, and it
    gives the error "write error 40 blocks into volume 1: Input/output
    error".

    I have no reason to believe the tape drive doesn't support variable
    block sizes (although it does seem to be a crappy drive). I have run
    'mt -f /dev/st0 setblk 0', and tar's -z option works fine (although if
    I understand it correctly, tar and dump compress at different levels).
    The drive is used daily with uncompressed dump.

    Can anyone tell if I've done something wrong, or if there's some option
    I haven't set? Any certain way to tell whether this tape drive will do
    variable length blocks?

    More information.

    >From dmesg:
    st: Version 20030406, bufsize 32768, max init. bufs 4, s/g segs 16
    Attached scsi tape st0 at scsi0, channel 0, id 6, lun 0

    mt status:
    SCSI 2 tape drive:
    File number=2, block number=0, partition=0.
    Tape block size 0 bytes. Density code 0x40 (DLT1 40 GB, or Ultrium).
    Soft error count since last status=0
    General status bits on (81010000):
     EOF ONLINE IM_REP_EN

    Example dump:

    [ccameron@cgydc002 ccameron]$ sudo dump -0z -f /dev/nst0 /dev/sda7
    Password:
      DUMP: Date of this level 0 dump: Tue Oct 26 11:36:06 2004
      DUMP: Dumping /dev/sda7 (/) to /dev/nst0
      DUMP: Added inode 8 to exclude list (journal inode)
      DUMP: Added inode 7 to exclude list (resize inode)
      DUMP: Label: /
      DUMP: Compressing output at compression level 2 (zlib)
      DUMP: mapping (Pass I) [regular files]
      DUMP: mapping (Pass II) [directories]
      DUMP: estimated 258001 tape blocks.
      DUMP: Volume 1 started with block 1 at: Tue Oct 26 11:36:10 2004
      DUMP: dumping (Pass III) [directories]
      DUMP: write error 40 blocks into volume 1: Input/output error
      DUMP: Do you want to rewrite this volume?: ("yes" or "no") no
      DUMP: Do you want to start the next tape?: ("yes" or "no") no
      DUMP: The ENTIRE dump is aborted.

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  • Next message: Rik van Riel: "Re: BIND process size"

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