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How to backup data to tape

This document explains how to backup data to and from tape.
  • How to transfer data to tape
  • How to read back the data from tape

    How to transfer data to a tape

    This section explains how to backup files which have not been backed up by MIDAS when running (see Writing data to tape with the Lazy Logger). This can be accomplished in the high energy counting room where there is a DLT tape drive attached to isdaq04 (any machine with a DLT drive will suffice though).

    1. Put data on a disc partition with lots of spare space e.g. /data2/dragon.

    2. If you are not already on isdaq04, switch host.

    3. Go into the directory that contains the .mid files to be backed up.

    4. Enable the tape environment. Open a terminal and type:

      setenv TAPE /dev/nst0

      (The device /dev/nst0 is the tape drive located in high energy counting room, attached to isdaq04.)

    5. Put the tape in the recorder nst0.

    6. Check the status of the tape/recorder. Type:

      mtape status

    7. To transfer data, enter:

      mtape backup [run#_start] [run#_end]

      For example, mtape backup 1278 1490, would copy the files run01278.mid, run01279.mid, ..., run01490.mid from the current directory. Transferred files will be listed on the screen.

    Notes:

    If error messages occur, the tape recorder (nst0) may need cleaning. This is done with a cleaning tape made specifically for this purpose, which should be placed into the tape drive. When cleaning has finished, the tape drive will display a green light and the tape can be removed.

    How to read back data from a tape

    1. Follow similar steps as above. Open a terminal and set the tape environmet with the setenv procedure.

    2. Navigate to a directory where the data should be restored i.e. one with plenty of spare disc space e.g. /data2/dragon.

    3. Use the command:

      mtape restore [n_files]

      This will transfer the next n_files of data from the tape to the current directory.

    Notes:

    Useful commands:
    • mtape -h (lists available commands)
    • mtape rewind (rewinds to start of tape)
    • mtape seod (moves tape to end of recorded data)
    • mtape status (prints status information about tape)
    Michael Lamey
    August, 2002
    Catherine Neish
    March, 2003
    JEP
    22 December, 2005
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