Conference cookie::archive_backup

    
    About the TLZ07 compaction problem.  How is the device connected to the
    system?  Is it through some controller?  What I heard is that some
    controller does not support compaction, so even if the drive/media
    supports it, you can never use in compaction mode.
    
    Masami

    Masami,
    
    the tape is connected through KZPAA. The customer is using the tape already
    with compaction!
    
      Thomas

    
    About the compaction problem :
    
    How did the customer determine that the data is not compacted?  Is it
    through show dev/full command?
    
    Masami

    
    Thomas,
    
    We need to see your tapestart.com and storage show volume output of the
    tape that was used at the point of compaction mode failure.
    
    We have been testing this case locally.  If you setup the following
    things correctly in MDMS, it should work:
    
    1. Media triplets for TLZ07L drive should have DENS_N field COMP.
    
    2. MDMS tape volume must be configured as DENSITY=COMP.
    
    3. Initialize the tape with /media_format=COMP
    
    When I did all 3 stpes above, the backup through ABS works with the
    drive showing compaction mode (show dev/full).
    
    What I found out (by accident) is that when I tried it without step 1
    (dens_n field was blank in tapestart), and when ABS initialize the tape
    (first backup to be done after the volume is allocated), the show
    device/full output shows compaction disabled and MDMS volume database
    shows DENSITY = blank.
    
    
    Thanks,
    Masami

    
    The further investigation revealed that when you do storage allocate
    in the way that ABS does storage allocate, unexpected things may
    happen.

    $ storage -
    allocate/user=abs/media_type=tlz07/loc=headquarters/pool=pool_name

    which does not specify density, the density field in volume database
    may be changed depending on what was in tapestart.

    Case 1 :

    Tapestart.com has the following configuration.

    $    MTYPE_1    := TLZ07
    $    DENS_1     := 
    $    DRIVES_1   := NODE$MKA500:

    Volume database for the volume TEST01 says density is COMP.

    After running the above storage allocate command, it will change
    the density field of volume TEST01 to blank. 

    Case 2 :

    Tapestart.com has the following configuration.
     
    $    MTYPE_1    := TLZ07
    $    DENS_1     := COMP
    $    DRIVES_1   := NODE$MKA500:

    Volume database for the volume TEST01 says density is blank.
    After running the above storage allocate command, it will change
    the density field of volume TEST01 to COMP.

    --------------------

    Also, if you have more than one mtype_n name to be identical, the first
    set in the order is used.

    For example if you have the following configuration in tapestart :

    $   MTYPE_1   := TLZ07
    $   DENS_1    := 
    $   DRIVES_1  := node$mka500
    $!
    $   MTYPE_2   := TLZ07
    $   DENS_2    := COMP
    $   DRIVES_2  := node$mka500

    since ABS does not support as the criteria for storage allocate, it
    always pick the mtype_1's set (with dens_1 blank).

    Does this help?

    Supporting density and length field of MDMS volume database from ABS
    has been discussed before as possible features to be added.  Do a lot
    of people feel this is a critical feature?

    If you do, please start lobbying by sending mails to Judy Cross
    (COOKIE::CROSS).  We are in the planning cycle for the next release,
    and your input is appreciated.

    Thanks
    Masami

    
    I need some input about he information I posted in .-1.  Will it be
    a good idea to make a STARS article from this information?
    
    Masami