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      STACKER NOTE                                         STACKER NOTE
                          BACKING UP STACKER DRIVES
                          (Applies to Stacker 4.0)
      STAC FAX  4403 (08-17-1994)
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      BACKGROUND
      
      You can use your favorite backup program, like Fastback, Norton
      Backup, or the DOS backup program to back up your Stacker drives.
      A Stacker drive may be backed up like any other drive.  If you
      compressed drive C, have your backup program back up the files on
      Stacker drive C.
      
      COMMON QUESTIONS
      
         - Which drive do I back up?
         - Do I back up the STACVOL file?
         - Are the backed up files compressed?
         - How do I restore my backup made on a Stacker drive?
         - How do I read the Stacker Toolbox Backup Status Gauge in
           Windows?
           
      Which drive do I back up?
      
      Back up your compressed drive(s) as you normally would. If you
      have left any of your drives uncompressed and have installed
      programs or data on them, you should back them up also. You do
      not need to back up the small uncompressed drives that are
      created when you compress your drives. In order to determine
      which drives are the uncompressed "host" drives, go to the DOS
      prompt and type:
           STACKER <enter>
      You will see a display something like this:
           Drive C was drive C at boot time [D:\STACVOL.DSK = 123.4MB]
           Drive D was drive D at boot time
      In this example, the C drive is compressed and the D drive is its
      uncompressed physical drive. Back up the C drive and not the D
      drive.
      
      Do I back up the STACVOL file?
      
      Your backup software may display a large hidden file on your
      uncompressed drive called STACVOL.xxx. This file is the file that
      contains all of your compressed data. When you back up the
      Stacker drive, you have already backed up the contents of the
      STACVOL file, and you do not need to back it up again.
      
      Are the backed up files compressed?
      
      Stacker uncompresses files as they are read from the hard drive.
      They are then handed to the backup software in their original,
      uncompressed state.  If the backup software uses compression, it
      will recompress the files before storing them to diskette or
      tape.  This means that the files can be restored to any drive,
      compressed or not.
      
      How do I restore my backup?
      
      Restore your backup to any drive in the same way that you
      normally would. You should remember that your backed up data is
      uncompressed. If you restore it to a drive that does not have
      Stacker running, it will also be uncompressed on the target hard
      drive. This means that if you have had a major disk crash and are
      restoring your backup to that drive, you must first run the
      Stacker SETUP on that drive in order for the restored backup to
      be compressed. This may be important if the drive is not
      physically large enough to hold all of the backed up data.
      
      How do I read the Stacker Toolbox Backup Status Gauge?
      
      The Backup Status Gauge displays the percent of your drive that
      is not backed up. This report is based on the percentage of disk
      space (not number of files) not backed up. The Gauge takes into
      account both the number and size of files when displaying its
      report.
      
      The Backup Status Gauge examines the files on your drive for the
      archive bit. The archive bit is a DOS attribute that is "set" on
      each file whenever it is created or modified. Most backup
      programs "clear" this attribute whenever they back up a file. The
      backup programs can use the archive attribute to keep track of
      files that have changed since the last back up. In the same way,
      the Backup Status Gauge can report the same files by telling you
      what percent of your files have the archive bit set. See your DOS
      documentation for further information on the archive attribute.
      
                                    Note
         Not all backup methods clear the archive attribute. If you
          use such a method, the Backup Status Gauge will not show
                          your disk's true status.
                                      
      
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      Copyright 1994 Stac Electronics
