      -----------------------------------------------------------------
      STACKER NOTE                                         STACKER NOTE
      NO ADDITIONAL SPACE AFTER CONVERSION OF DOUBLESPACE OR SUPERSTOR
                        /DS DRIVES TO A STACKER DRIVE
                          (Applies to Stacker 4.0)
      STAC FAX  4015 (06-24-1994)
      -----------------------------------------------------------------
                                      
      BACKGROUND
      
      In certain cases you may find that your drive size does not
      increase after upgrading to Stacker 4.0. This occurs when you are
      near the DOS limit for that drive. DOS's limits are related to
      the size of clusters used on the drive. The following table
      compares cluster size and drive size.
      
      Cluster Size (Allocation Unit)/Largest Logical Drive Size
                 8KB                            512MB
                16KB                      1GB (1024MB)
                32KB                      2GB (2048MB)
      
      Note that DoubleSpace and SuperStor /DS drives are normally set
      up with 8KB clusters. That limits the maximum logical size of the
      drive to 512MB. Stacker 4.0's Setup tries to give your drive the
      advantage of increased compression when you upgrade. But that
      increased compression may require your drive to cross the
      boundary between one cluster size and the next. Because Stacker
      cannot dynamically change cluster size, your drive is limited to
      the largest drive possible for the current cluster size.
      
                                    Note
                   StacFax 4505 discusses large compressed
                           drives & cluster size.
      SOLUTION
      
         - Recompress the drive.
         - Accept the current configuration.
         - Uncompress your drive and re-run Setup.
         - Shrink then grow the Stacker drive.
           
      Recompress the drive
      
      Make sure that you have recompressed the drive after upgrading to
      Stacker. If you have not already done so, open the Stacker
      Toolbox and select Optimize. Choose Full-MaxSpace. After the
      operation completes, check the space available on your drive.
      Accept the current configuration
      
      If you prefer your current configuration, simply use your system
      as before. You will still benefit from Stacker's improved safety,
      the Stacker Toolbox, and use of DPMS if you have DOS 6 or above.
      
      Uncompress your drive and re-run Setup
      
      If you do not gain any additional space after running the Stacker
      Optimizer, then uncompress your Stacker drives and run Stacker
      Setup again. This will allow Stacker to select the proper cluster
      size for your drive in relation to the data on the drive and the
      expected compression ratio. See your Stacker User's Guide for
      instructions on uncompressing your drive. This is the recommended
      method for gaining the most possible space.
      
      Shrink then grow the Stacker drive
      
      An alternate method of gaining additional space is to shrink,
      then grow, the Stacker drive. This method will not permit a new
      cluster size, but may gain additional space within the current
      drive limits.
      
       1.  Go to the DOS prompt and change to the Stacker directory.
           Type STACKER <enter>. Look for a line something like this:
           Drive C was drive C at boot time [D:\STACVOL.DSK = 256.0MB]
           Note the size of the STACVOL file listed.
       2.  See chapter 4 of the Stacker User's Guide for instructions
           to make your Stacker drive smaller. You will be using the
           option to make more uncompressed space. When asked how much
           uncompressed space to add, use this formula:
           Size of STACVOL file (noted above) -(Largest drive size
           allowed by cluster size/2.5)
      
           For example, if your STACVOL file is 256.0MB, and you have
           8K clusters, you would  add 51.2MB of uncompressed space.
           256 - (512/2.5) = 51.2.
       3.  After the resizing of the Stacker drive is complete, use the
           Stacker Toolbox to run the Stacker Optimizer, choosing Full-
           MaxSpace.
       4.  After the optimization is complete, again change your
           Stacker drive size. In this case, choose the option to
           increase your Stacker drive. Grow it to the maximum size
           offered.
       5.  You will have unused uncompressed space on your drive after
           you complete this procedure. If you wish, you may use the
           Stacker Toolbox to create an additional Stacker drive on
           that space.
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      Copyright 1994 Stac Electronics
