TITLE: Stacker with Other Utilities and Environments DOCUMENT ID: TID14813 DOCUMENT REVISION: 1 DATE: 09FEB94 ALERT STATUS: Yellow README FOR: NA NOVELL PRODUCT and VERSION: Novell DOS 7 ABSTRACT: NA --------------------------------------------------------------------- DISCLAIMER: 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. --------------------------------------------------------------------- Any trademarks referenced in this document are the property of their respective owners. Consult your product manuals for complete trademark information. ---------------------------------------------------------------------