Making tape backups of diffraction data

revised 7/24/98

The following tape drives can be used to back up frames:

Tape format Host computer Device name Location
8 mm herb /dev/tape S-1061
4 mm mar /dev/tape S-1067
4 mm raxis /dev/tape S-1067
4 mm blue /dev/tape S-1061
4 mm charybdis /dev/tape S-1272

For any device the procedure is the same:

    Log in to the appropriate host computer and change to the directory containing your x-ray frames.

    Insert a new tape (unless you are a unix expert it is safest to use a new tape for each backup). 8mm tapes (120 meters) will hold 2.4Gb. 4 mm tapes (120 meters) will store between 4 and 8 Gb, since the drives provide hardware compression.

  1. Create a tape archive based on the following example: 
    2. tar -cvf /dev/nrtape . >& ~waddling/tar00may19

    In this example, 'c' creates a new tape, 'v' gives verbose output, 'f /dev/nrtape' writes the archive to the 8mm tape device, the period archives files in the present directory and all subdirectories, and '>& ~waddling/tar00may19' writes a permanent record of the archive to the file tar0may19 in waddling's home directory. Note--any attempt to write a second archive to the tape is likely to erase the first archive. It is highly advisable to protect your tape using the write-lock tab.

  2. You can check the status of your tape or rewind it with the following commands: 
    3. mt -f /dev/nrtape status 
mt -f /dev/nrtape rewind
  3. You can list the contents of an existing tape with 
    4. tar -tvf /dev/nrtape

    and recover files by changing to an empty directory and using 

    tar -xvf /dev/nrtape
  4. It is always advisable to make two backup tapes.


    5. Return to Policies Page.

    Return to MSG Home Page. 

    Web page maintained by Chris Waddling. Last modified: 5/19/00