      -----------------------------------------------------------------
      STACKER NOTE                                         STACKER NOTE
                  Using Surface Scan Utilities with Stacker
                         (Applies to Stacker 4.0)
      STAC FAX  4411 (08-17-1994)
      -----------------------------------------------------------------
                         
      BACKGROUND
      
      If a physical hard drive flaw (bad sector) affects the operation
      of your Stacker drive, then a disk repair utility can be used to
      detect the damaged areas and correct them.  This procedure
      explains how to use a disk repair utility to repair hard drive
      flaws in conjunction with Stacker.  Norton Utilities' Calibrate,
      PC Tools' DiskFix, and SpinRite are examples of disk surface scan
      utilities.
      
      SOLUTION
      
       - Ensure that a file attribute utility is available
       - Boot without loading device drivers
       - Unhide the STACVOL file
       - Run the surface scan on the physical hard drive
       - Correct coincidental damage to the Stacker drive.
        
      Ensure that a file attribute utility is available
      
      From the DOS prompt type STACKER <enter>. Locate the line that
      displays drive C. It will look something like this:
      
           Drive C was drive C at boot time [E:\STACVOL.DSK = 123.4MB]
      The drive letter in brackets (in this case drive E) is your
      uncompressed boot drive. Go to the STACKER directory on that
      drive. Copy the file SATTRIB.EXE from the STACKER directory on
      the C drive.
      
      Boot without loading device drivers
      
       1.  Clean boot your system using a bootable floppy diskette.
           "Clean boot" means to start your computer without loading
           any device drivers into memory, including Stacker.  Refer to
           your DOS user's guide if you do not have a bootable floppy
           diskette.
       2.  Note:  if you use MS-DOS 6.22, a bootable floppy disk may
           still try to mount your Stacker drive. If so, go to the
           STACKER directory on the uncompressed drive you determined
           above and type:
           SATTRIB -S -H -R C:\DBLSPACE.BIN
       3.  Type:
           REN C:\DBLSPACE.BIN C:\DBLSPACE.SAV

      Unhide the STACVOL file
      
      After clean booting, your computer will display an A prompt.
      Change to drive C and go to the STACKER directory. Type:
           SATTRIB -S -H -R DRIVE:\STACVOL.* <enter>
      where drive is the letter of the drive you are repairing.  This
      command unhides all STACVOL files on the specified drive.
      
      Run the surface scan on the physical hard drive
      
       1.  Follow the disk repair utility's instructions for running
           from a floppy disk. Use the most rigorous pattern testing
           available (typically 80-pattern) to scan the physical drive
           containing the STACVOL file, and allow it to repair
           defective areas on the disk. A rigorous surface scan may
           take several hours, depending on the size and speed of your
           hard drive.
           Note:  If you are using Norton CALIBRAT.EXE to perform
           pattern testing, it defaults to low-level formatting. IDE
           drives cannot be low-level formatted, so you must override
           low-level formatting with the following command:
           calibrat /noformat
       2.  If you had to rename the DBLSPACE.BIN file in order to
           execute a clean boot, then you will need to name it back to
           its original name. Go to the root directory of drive C. Type
           REN DBLSPACE.SAV DBLSPACE.BIN <enter>
       3.  Remove all diskettes from the floppy drives and restart the
           computer.
           
      Correct coincidental damage to the Stacker drive
      
       1.  Switch to the compressed drive, change to the \STACKER
           directory, and type:
           check /f <Enter>
       2.  When CHECK prompts you to perform a disk surface test,
           respond "yes."
       3.  If CHECK detects errors and prompts you to delete damaged
           files, respond "yes," then complete the on-screen
           instructions that CHECK displays.
           
      
      -----------------------------------------------------------------
      Copyright 1994 Stac Electronics
