

              NOVELL TECHNICAL INFORMATION DOCUMENT

TITLE:              Stacker with Other Utilities and Environments
DOCUMENT ID:        TID014813
DOCUMENT REVISION:  A
DATE:               09FEB94
ALERT STATUS:       Yellow
INFORMATION TYPE:   Issue
README FOR:         NA

NOVELL PRODUCT and VERSION:
Novell DOS 7

ABSTRACT:

This document explains the use of the Novell DOS 7 STACKER data
compression utility with third-party software.

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THE ORIGIN OF THIS INFORMATION MAY BE INTERNAL OR EXTERNAL TO
NOVELL.  NOVELL MAKES EVERY EFFORT WITHIN ITS MEANS TO VERIFY
THIS INFORMATION.  HOWEVER, THE INFORMATION PROVIDED IN THIS
DOCUMENT IS FOR YOUR INFORMATION ONLY.  NOVELL MAKES NO EXPLICIT
OR IMPLIED CLAIMS TO THE VALIDITY OF THIS INFORMATION.
------------------------------------------------------------------

ISSUE

     USES OF THE NOVELL DOS 7 STACKER DATA COMPRESSION UTILITY
     WITH THIRD-PARTY SOFTWARE

     COMPATIBILITY

     This document is not designed to be an introduction to the
     STACKER portion of Novell DOS 7.  Users who are new to
     STACKER should read the following references before reading
     this document:

          Novell DOS 7 User Guide: Chapter 12 "Disk Compression"
          Novell DOS 7 README.TXT
          STACKER section within the DOSBOOK online reference
          manual (Type DOSBOOK STACKER at the command line.)

     STACKER from Novell DOS 7 has been tested and found to be
     compatible with virtually every piece of hardware and
     software available.  Only a few instances exist where normal
     operating procedures must be altered for STACKER to operate
     properly on your system.

     OTHER DISK OPERATING SYSTEMS (DOS)

     The Novell DOS 7 STACKER utility should not be used on any
     operating system other than Novell DOS 7.  Stac Electronics,
     manufacturer of STACKER, offers retail versions of STACKER
     that are designed to work with other disk operating systems
     such as MS-DOS, Compaq DOS, or PC DOS.

     DOS versions before 3.31 created partitions larger than 32
     MB by altering the sector size of the hard disk.  The Novell
     DOS 7 STACKER utility cannot be installed on a drive with

     sector sizes other than 512 bytes.  The Novell DOS 7 FDISK
     utility may be used to repartition a drive that was
     previously partitioned using a nonstandard sector size.

     OS/2 OPERATING SYSTEMS

     STACKER drives created with Novell DOS 7 can only be
     accessed under OS/2 if the STACKER for OS/2 and DOS product
     has been installed.  Stac Electronics offers a retail
     product, STACKER for OS/2 and DOS, that will allow you to
     access a STACKER drive under the OS/2 operating system.

     FORMAT AND DISKCOPY COMMANDS

     WARNING:  Using the FORMAT command on the drive that
               contains the STACVOL file will result in losing
               all the data on the STACKER drive.  Remember, the
               STACVOL file is your STACKER drive.  The Novell
               DOS 7 XDIR command will display hidden STACVOL
               files if you are unsure whether one exists.

     The Novell DOS 7 FORMAT and DISKCOPY commands have no
     influence on stacked removable media (floppy diskettes)
     while they are mounted.  If you need to use the Novell DOS 7
     FORMAT or DISKCOPY command on a stacked removable, unmount
     the STACKER drive first.  Please see the Novell DOS 7 User
     Guide for information on how to unmount a stacked removable
     (floppy diskette).

     SUBST, JOIN, AND ASSIGN COMMANDS

     The Novell DOS 7 STACKER utilities will not operate on
     drives that have been created or altered with the SUBST,
     JOIN, or ASSIGN commands.

     DISK OPTIMIZERS

     Third-party disk optimizers, such as PC Tools Compress or
     Norton Speed Disk, should not be used on a STACKER drive
     created with Novell DOS 7.  Novell DOS 7 includes its own
     optimizer, DISKOPT, for use on STACKER drives.  See the
     Novell DOS 7 User Guide or DOSBOOK CHKDSK for further
     information about DISKOPT.

     The Novell DOS 7 CHKDSK command may be able to repair a
     drive in an instance where a third-party disk optimizer has
     accidentally been used on a STACKER drive.  Any errors
     reported by CHKDSK may be fixed in the normal fashion.  See
     the Novell DOS 7 User Guide or DOSBOOK CHKDSK for further
     information about CHKDSK.

     DISK REPAIR UTILITIES

     Early versions of Norton Utilities 7.0 will incorrectly
     diagnose a converted SuperStor or DoubleSpace drive as a
     faulty drive.  THIS IS NOT A FAULT ON THE DRIVE.  Please
     contact your supplier for an updated version of the Norton
     utility.

     The Novell DOS 7 STACKER utility is fully compatible with
     third-party disk repair utilities such as Norton Disk

     Doctor, PC Tools DiskFix, and SpinRite.  However, these
     utilities will not understand the internal structures
     specific to the STACKER compressed drive.  Instead, all disk
     repair utilities should be run on the uncompressed portion
     of the STACKER drive (the drive that contains the STACVOL
     file).

     The steps for using disk repair utilities on a STACKER drive
     are as follows:

     WARNING:  Failure to make a backup of your system before
               attempting to use a disk repair utility on a drive
               may result in data loss.

     1.   Novell strongly recommends that you make a backup of
          your system before attempting to use a disk repair
          utility on a drive.

     2.   Boot your system from a clean bootable floppy diskette
          that does not contain the STACKER driver (STACKER.BIN
          file).

     3.   Execute the disk repair utility from your hard disk. 
          The repair utility may be run from the hard disk if the
          utility resides on an uncompressed drive.  Otherwise,
          the utility may be run from a floppy diskette.

     4.   Do not allow the utility to automatically fix the
          errors it has found.  If the disk repair utility
          detects an error that is not inside the STACVOL file,
          allow the utility to fix the error.  However, if the
          disk repair utility detects an error within the STACVOL
          file on your hard disk, do the following:

          4a.  Exit the disk repair utility.

          4b.  Remove the attributes on the STACVOL file that has
               the error.  This can be done using the Novell DOS
               7 ATTRIB command as shown in the following
               example:

                    ATTRIB -RSH C:\STACVOL.DSK

          4c.  Execute the disk repair utility and allow it to
               repair the defective area.

          4d.  Restart your system.  During reboot the attributes
               should be reapplied to the STACVOL file
               automatically.

     DISK-PARTITIONING PROGRAMS

     DOS versions before 3.31 created partitions larger than 32
     MB by altering the sector size of the hard disk.  Often this
     was done by a third-party disk partitioning utility that was
     shipped with the operating system (not of the operating
     system itself).  The Novell DOS 7 STACKER utility cannot be
     installed on a drive with sector sizes other than 512 bytes.
     The Novell DOS 7 FDISK utility may be used to repartition a
     drive that was previously partitioned using a nonstandard
     sector size.


     BACKUP PROGRAMS

     The Novell DOS 7 STACKER utility is fully compatible with
     third-party disk backup utilities such as Fastback Plus,
     Norton Backup, and PC Tools Backup.  You can back up your
     STACKER drive just as you back up any other drive.

     If your backup program uses compression, expect an increase
     in the time it takes to perform the backup.  This is because
     STACKER will not only have to uncompress the data but the
     backup program needs to recompress the data before writing
     it to the destination drive.

     Novell DOS 7 contains its own advanced backup program,
     Fastback Express, that may be used to back up both stacked
     and nonstacked drives.  See the Novell DOS 7 User Guide or
     DOSBOOK FBX for further information about Fastback Express.

     ANTI-VIRUS PROGRAMS

     Some anti-virus programs detect viruses by adding their own
     specific code (called a CHECKSUM) to each individual .EXE
     and .COM file on a drive.  This checksum code is used by the
     antivirus program to detect change within the executable
     file.  If the checksum of the executable file changes, the
     antivirus program suggests that a virus may have infected
     the file.

     Certain Novell DOS 7 STACKER executable files may not
     operate properly if modified by an antivirus program.  If
     problems surface with a modified STACKER executable file,
     reinstall the executable to your hard disk from the
     appropriate Novell DOS 7 diskette.  Novell DOS 7 contains
     its own virus detection and removal software, Search and
     Destroy, that may be used to detect viruses on both stacked
     and nonstacked drives.  Search and Destroy does not use the
     checksum method to detect viruses in an executable file. 
     See the Novell DOS 7 User Guide or DOSBOOK SECURITY for
     further information about Search and Destroy.

     DISK CACHING SOFTWARE

     The Novell DOS 7 STACKER utility is fully compatible with
     third-party disk caches such as Microsoft's SMARTDRV and
     Super PC Kwik's SUPERPCK.  In fact, because STACKER stores
     data in a compressed format, the size of your cache is
     theoretically doubled when used on a STACKER drive.

     Most caching programs will allow you to choose that drives
     on your system to cache.  If you choose to cache a STACKER
     drive, you will want to configure the cache to operate on
     the uncompressed portion of the STACKER drive (the drive
     that contains the STACVOL file) instead of on the drive
     where the compressed data resides.  Using the cache on the
     uncompressed portion of a STACKER drive causes the caching
     software to cache reads and writes to the STACVOL file.

     If the drive that contains the STACVOL file has been
     replaced using the STACKER.INI RP (replace) drive mounting
     parameter, the drive cannot be cached.  To cache a replaced
     drive, change the RP parameter for the STACVOL file that you

     wish to cache to the SW (swap) parameter in the STACKER.INI
     file.

     Novell DOS 7 contains its own advanced caching software,
     NWCACHE, that may be used to cache a STACKER drive's
     uncompressed portion.  See the Novell DOS 7 User Guide or
     DOSBOOK NWCACHE for further information about NWCACHE.

     NOTE:     Most caching software, such as NWCACHE, will
               recognize a compressed drive and configure itself
               to cache its uncompressed portion automatically.

     NETWORKS (NON-DOS BASED)

     The Novell DOS 7 STACKER utility should have no problems
     coexisting within a network environment such as Novell
     NetWare.  However, STACKER cannot be used to compress a
     network drive, because these drives are not based on a DOS
     file structure.

     STACKER may create additional drive letters on your system. 
     Care should be taken not to overwrite these drives with
     network drive mappings.  Although this is a temporary
     situation (it only occurs while you are logged into the
     network), it will cause certain STACKER utilities not to
     operate (such as UNSTACK).

     PEER-TO-PEER NETWORKS (DOS BASED)

     The Novell DOS 7 STACKER utility may be used on peer-to-peer
     networks, such as Novell's PERSONAL NetWare.  Drives that
     are on a desktop server may be compressed and shared among
     network users.  Network users will be able to take advantage
     of the doubling of any shared drive.

     NOTE:     If you are unsure about the compatibility between
               your peer-to-peer network and STACKER, please
               contact the manufacturer of your networking
               software.

     VDISK

     The Novell DOS 7 STACKER utility may be used to stack a
     VDISK.  The following steps need to be taken to stack a
     VDISK successfully:

     1.   In the CONFIG.SYS file, you must create the VDISK.  Be
          sure to use a sector size of 512 KB.  STACKER can only
          stack disks that have 512 KB sector size.  The
          following is an example of a VDISK line in the
          CONFIG.SYS file:

               DEVICE=C:\NWDOS\VDISK.SYS 1024 512 64 /E:8

          For more information about VDISK, please refer to
          DOSBOOK.

     2.   In the CONFIG.SYS file after you have created the
          VDISK, you must create the STACKER drive within the
          VDISK as shown in the following example:


               DEVICE=C:\NWDOS\SCREATE.SYS X:

          (where X refers to the drive letter of your VDISK.)
          This will create a STACVOL.DSK on the VDISK.  The drive
          must now be mounted before you will be able to use the
          VDISK.

     3.   To mount the VDISK, you should use the STACKER command.
          You can issue this command at the command line or place
          the command in your AUTOEXEC.BAT file.

               STACKER X:

          (where X refers to the drive letter of your VDISK.) 
          Your VDISK should now be approximately twice the size
          set in the CONFIG.SYS file.

          NOTE:     If you have stacked a diskette or are using
                    the replace (RP) switch to automatically
                    mount any of your stacked drives, you will
                    need to add the following line to your
                    STACKER.INI file:

                         /RP=2

                    The value of this switch is the number of
                    replaceable drives plus one.
