Backing up your data using the tape drive

General information

The local scratch disks and the drives on hera and elektra are not backed up and the drives will eventually fail, it is only a matter of when. To back up the large amounts of data on these drives we have a tape drive connected to phaedra in room 302C and tapes that hold 100GB of data, which are located in room 312H.

Step-by-step instructions

  1. Assemble all the data that you want to back up into a meaningful directory structure in your scratch directory. It's useful to put everything in one directory, ~/Scratch/TAPE_BACKUP/ for example. Then you need to get a tape from the box labeled "Ultrium Tapes" in room 312H and log onto phaedra in room 302C.

  2. You need to make sure the tape drive is turned on and recognized. Run this command to see if the drive is recognized:
    cat /proc/scsi/scsi
    and in the output, you should see a line that includes "Vendor: HP Model: Ultrium 1-SCSI Rev: N27D." If you do then you can move on to step three, but if you do not you need to run this command exactly as shown:
    sudo /bin/rescan-scsi-bus.sh
    Now check /proc/scsi/scsi again to make sure the drive is recognized.

  3. Place the tape in the drive by opening the door to the tape drive and inserting the tape with the arrow pointing into the tape drive. Do not force the tape, the drive will seat the tape automatically if you give it a little push. To perform the backup, go to the directory where you copied your data, in my example this is ~/Scratch/. You then run this tar command:
    tar -cvWf /dev/st0 TAPE_BACKUP
    The -W flag is to verify the data, and TAPE_BACKUP is the directory where the data is stored. It takes roughly an hour to back up 10GB of data and when the process is finished the tape will rewind automatically. Eject the tape with this command:
    mt -f /dev/st0 rewoffl
    It is a VERY good idea to label your tapes with what you backed up, the size, and the date. Labels are provided in the tape cases.

  4. To restore a backup, follow step 2, then insert your tape. Move to a scratch directory with enough free space and run this command:
    tar -xvf /dev/st0

    5. Back to pointers and information

    This page was last updated on February 12, 2008.