Hard drives have undergone phenomenal growth. 250MB drives that were considered spacious just a few years ago are now considered insignificant against the 3GB, 4GB, and 5GB+ drives that are now on store shelves. While the battle for ever-larger drives has been waged relentlessly by drive manufacturers, the struggle to actually use those massive drives has rested squarely on the shoulders of computer users. Since traditional BIOS calls for ATA drives limit drive sizes to 528MB, making use of space beyond the 528MB mark has required PC users to employ several different tactics. Updated motherboard BIOS and ATA-2 (Enhanced IDE or EIDE) controllers have been two popular solutions, but the drive overlay software from manufacturers like Ontrack has proven to be particularly useful.

Software solutions like Disk Manager or EZ-Drive allow older systems to access the full capacity of a drive without ever touching the PC’s hardware. Still, software solutions are not always as elegant and reliable as we would like to believe, and overlay software is certainly subject to a range of performance and compatibility problems under the right circumstances. This chapter provides symptoms and solutions for three premier drive overlay software products; Disk Manager, EZ-Drive, and Drive Rocket.

Ontrack’s Disk Manager is a utility that partitions and formats a hard drive, and allows you to access the full capacity of the drive (even when your system BIOS is unable to do so). Current versions of Disk Manager arer fully compatible with 32-bit disk and file access under Windows 3.1x and Windows 95. The Disk Manager driver is loaded from the Master Boot Record (MBR) when drive is set up as a primary ("master") drive. When the drive is set up as a secondary ("slave") drive, Disk Manager is called by the CONFIG.SYS file.

Symptom 35-1. You are having difficulty installing Ontrack’s Disk Manager software from the B: drive. Ontrack software must be installed from the A: drive. If your A: drive is the wrong size for your Ontrack distribution diskette, copy the diskette to a floppy disk sized properly for drive A:, then try reinstalling Disk Manager.

Symptom 35-2. Windows 95 reports that the system is operating in "DOS Compatibility Mode". This type of problem is not necessarily related to Disk Manager (though older versions or poorly configured installations can cause the problem). The "DOS Compatibility Mode" is invoked by Windows 95 whenever the system loads a real-mode driver. This would happen when Windows 95 does not have an equivalent 32-bit protected-mode driver to replace a real-mode driver. Click on the Performance page under the System icon for details on what devices are causing the problem. Often, this problem is triggered when real-mode drivers for a device are loaded in CONFIG.SYS and AUTOEXEC.BAT. Try disabling any such real-mode entries, then restart the system. If the problem persists, make sure that you are using the latest protected-mode driver version for each device.

Symptom 35-3. Disk Manager does not appear to function properly with Windows 95. In virtually all cases, you are using an older version of Disk Manager. Version 6.0 or higher is known to work with Windows 95. It may be necessary to download the patch file (DMPATCH.EXE) from the Ontrack Internet web site (www.ontrack.com) which will update the Dynamic Drive Overlay (DDO) to 6.03d.

Symptom 35-4. When using Disk Manager 6.0x, Windows 95 reports operating in the "DOS Compatibility Mode". Although Disk Manager version 6.0x is supported by Windows 95, there are some factors that can keep the utility from running properly with Windows 95. First, be sure that the number of cylinders set for the drive under CMOS Setup is 1024 or less - there are often "translation geometries" available from the drive maker that provide alternate entries for heads, sectors, cylinders, and so on.

Next, be sure that any 32-bit disk access drivers (such as WDCDRV.386) loaded in the Windows 3.1x SYSTEM.INI file are disabled prior to installing Windows 95 in the first place. Otherwise, you will need to edit the [386Enh] portion of your SYSTEM.INI file and disable 32-bit disk access by inserting a semicolon before the driver entry such as;

;32Bit DiskAccess=On

You could also simply change On to Off on this line. Windows 95 provides its own 32-bit protected-mode drivers for support of your IDE drives. Finally, check once again to be sure that you are in fact using the latest version of Disk Manager. If not, you can download the 6.03 patch file (DMPATCH.EXE) from the Ontrack Internet web site.

Symptom 35-5. You encounter trouble with the disk driver (such as WDCDRV.386) for 32-bit disk access in Windows 95. Don’t use any third-party disk drivers under Windows 95 - which provides its own native IDE protected-mode drivers. If there are still references to third-party disk drivers in SYSTEM.INI, you will need to edit those references out manually as noted in Symptom 35-4.

Symptom 35-6. When installing a new, large drive (and reinstalling Disk Manager to the new drive), you encounter errors with cluster sizes. In virtually all cases, you are using an older version of Disk Manager which does not support cluster sizes over 8KB. Be sure to obtain the very latest version of Disk Manager which will support larger cluster sizes.

Symptom 35-7. Disk Manager fails to identify the hard drive correctly. Some OEM versions of Disk Manager (such as the version distributed by Western Digital) check for the presence of a particular hard drive. Disk Manager starts by sending a query to the drive. If the response is anything other than the expected ID, Disk Manager will produce an error message. Some sophisticated IDE cards will intercept queries and commands sent to the drive. This will cause Disk Manager to believe there is no expected drive - even if there is. You should try to disable the BIOS on your controller, or format the drive using another controller card to avoid this problem (or use a generic commercial version of Disk Manager).

Symptom 35-8. You have problems removing Disk Manager. Disk Manager installs itself in the Master Boot Record (MBR) of your primary ("master") hard drive. To eliminate Disk Manager, you simply need to boot from a bootable diskette, repartition the hard drive with FDISK, then reformat the drive. Keep in mind that this process is destructive to your data - be sure to perform a complete backup of the drive before proceeding.

Symptom 35-9. You find "Out of disk space" errors after loading as little as 800MB of data onto a 1GB drive. This is not a direct effect of Disk Manager (though it may appear so). In reality, you are seeing a limitation of the FAT 16 (DOS) file allocation system which is based in clusters. In DOS, every file that is stored gets at least one cluster (or "allocation unit") no matter what the size of the file is. The size of the cluster grows incrementally with the size of the partition. For example, if you have a 1.08GB partition, the cluster size will be 32KB - this means that even a 62 byte batch file is going to consume 32KB of storage space (the difference between the 32KB cluster size and the 62 bytes that the file really needs is called "slack space"). The only feasible way to reduce the cluster size is to reduce the partition size. To utilize drives larger than 2.1GB under FAT 16, you need to create additional partitions.

Symptom 35-10. Disk Manager appears to conflict with other programs in conventional memory. The dynamic drive overlay (DDO) used by Disk Manager first loads into conventional memory where it takes 6KB. It then moves into 4KB of upper memory. When the program code leaves conventional memory, it leaves a 62 byte "footprint" at the top of conventional memory. This "footprint" can sometimes conflict with other programs. You may have to change how Disk Manager loads. During the boot process, when you see the message which tells you to press the space bar to boot from a floppy disk, press the "S" key instead, then answer "Y" to the next question. This will cause Disk Manager to stay in conventional memory rather than moving to high memory, and may resolve the conflict you are experiencing.

If this does resolve the problem, there is a special version of Disk Manager (LOADLOW.ZIP) which will prevent you from having to hit the "S" key every time you boot. You can obtain the file from the Ontrack BBS at (612)-937-0860, or from the Ontrack Internet web site (www.ontrack.com).

Symptom 35-11. Disk Manager installed properly and responded as expected, but after installing DOS 6.2, the drive ended up at 504MB. In order to install DOS properly, you must load the dynamic drive overlay (DDO) before running the DOS installation floppy. Start by booting from the hard drive. When you see the message; "Press spacebar to boot from diskette", press the <Space Bar>, insert the DOS startup diskette, and press any key to continue. The boot process will proceed from the floppy, but the DDO will have had a chance to load into memory first - the partitions will now make sense, so the DOS installation will not overwrite the partition information.

Symptom 35-12. Disk Manager installed and ran properly, but now you get a "DDO Integrity Error", and cannot access the hard drive. This is a very serious error that indicates the hard drive sector containing the DDO (dynamic drive overlay) information has become corrupted. Such problems can be caused by:

• infection by a boot or partition sector virus (boot from a clean DOS diskette and run a virus scan software).
• a power surge.
• a hardware failure (usually the controller card).
• shutting the computer down in the middle of a write process.

Unfortunately, there is little that can be done to correct the problem. If a virus is found and eliminated, you can re-install Disk Manager. If hardware is at fault, you will have to replace the hardware. In either case, any data on the drive that is not backed up will be lost.

Symptom 35-13. You can only get 16-bit file access on the secondary ("slave") drive formatted with Disk Manager. When Disk Manager is used to format the primary ("master") drive, the DDO is loaded during the boot process. In this situation, there is no device=dmdrvr.bin line in the CONFIG.SYS file. When Disk Manager is used to prepare the secondary ("slave") drive and the primary drive was prepared without Disk Manager, there will be a driver loaded in the CONFIG.SYS file, and the DDO is loaded differently. It is this difference in how the DDO is loaded that is causing the 16-bit file access on the secondary drive. The only solution here is to back up all the data on the primary drive and prepare it also with Disk Manager. This causes the DDO to be loaded during the boot process and allow 32-bit file access on both drives.

Symptom 35-14. Drive letters are all switched around when booting from a bootable diskette. DOS allocates drive letters every time you boot. It starts first on cylinder 1, then goes on to subsequent cylinders looking first for primary DOS partitions, and then for DOS extended partitions. When this allocation is complete, DOS then proceeds to allocate drive letters as requested by drivers loaded in CONFIG.SYS (i.e. CD-ROMs, hardcards, and so on). When you boot from a hard drive, the dynamic drive overlay (DDO) is loaded before DOS. This means that when DOS looks at cylinder 1, it can identify that primary DOS partition, and assigns it to C:. It then goes to the second drive and allocates D:. When you boot from a floppy, the driver line in CONFIG.SYS (dmdrvr.bin) starts the DDO - but not until after DOS has already assigned drive letters. Because the DDO wasn't in memory when it looked at cylinder 1, it did not see that partition. It did see the partition on the non-Disk Manager cylinder and that became C:. When CONFIG.SYS loaded the driver which started the DDO and asked for drive letters, DOS saw the partition on cylinder 1 and gave it the next drive letter - D:.

An easy way to avoid this problem is to start the boot from the hard drive. When you see the "Press spacebar to boot from diskette" message, press the spacebar to halt the boot process and insert your boot floppy. The boot will continue on the floppy, but DDO will have loaded and the drive letters will be allocated as usual.

Symptom 35-15. You have trouble creating a floppy so that you can boot from a diskette and still have the DDO load. You should insert a floppy disk and use the DMCFIG utility such as:

DMCFIG /d=a:

You will need to answer a series of questions as DMCFIG runs.

Symptom 35-16. You encounter problems using certain utilities on your hard drive. Generally speaking, utilities that use interrupt 13 for communicating with drive hardware will be compatible with Disk Manager. Utilities that attempt to communicate with drive hardware directly may encounter some problems and data corruption. Be suspicious of any disk utility that claims high performance by communicating directly with drive hardware.

EZ-Drive is very similar in nature to Disk Manager - it provides large-drive support for older BIOS. It also works around problems with BIOS versions that hang on drives larger than 2.1GB. As with Disk Manager, however, EZ-Drive also suffers from its share of problems under the right conditions.

Symptom 35-17. EZ-Drive refuses to work properly with the system’s VLB IDE controller. EZ-Drive has a number of compatibility problems with some VL bus drive controllers. Fortunately, there is a workaround in most cases:

• Appian ADI2 - This is fully compatible. The HVLIDE.SYS driver is fully compatible with EZ-Drive. The ADI2C143.SYS driver is also fully compatible with EZ-Drive. Install EZ-Drive, then install one of these drivers into your CONFIG.SYS file.
• CMD640x - This is fully compatible. The CMD640X.SYS driver is fully compatible with EZ-Drive. Install EZ-Drive, then install the driver into your CONFIG.SYS file.
• PC Tech RZ1000 - This is not supported. The ZEOS/Phoenix BIOS does not need EZ-Drive as it natively supports large drives. If EZ-Drive sets up a large drive, it will take over from the BIOS and the drive will be slower than with native BIOS support. Set up the drive through BIOS and not EZ-Drive.
• Opti 611A & 621A - This is not supported by any product or hardware. The OPTIVIC.SYS driver (dated 5-11-94) is incompatible with large drives - with and without EZ-Drive. An updated driver is under development by Opti.

Symptom 35-18. The keyboard or mouse does not function normally after exiting Windows on an EZ-Drive system. This is almost always due to a problem with the mouse driver installation. Some mouse drivers change a line in the SYSTEM.INI file to:

Keyboard=C:\MOUSE\mousevkd.386

To correct the problem, change that line in the SYSTEM.INI file back to;

Keyboard=*vkd

Symptom 35-19. With EZ-Drive installed on the system, QEMM 7.5 will not load in Stealth Mode. This is often a problem with QEMM related to the way in which QEMM processes software interrupt 76. Add the following switch to the QEMM command line in CONFIG.SYS which will force QEMM to ignore software interrupt 76;

XSTI=76

Symptom 35-20. Windows crashes with EZ-Drive installed on my drive. This problem has been reported on systems using Award BIOS version 4.50G. There is a patch file available from MicroHouse (EZPCH502.EXE) which can update the EZ-Drive MBR. You can download the patch file from the MicroHouse BBS at (303)-443-9957 or from the web (www.microhouse.com).

Symptom 35-21. You have trouble removing EZ-Drive from the system. You will need to re-write the drive’s Master Boot Record (MBR). Disable any BIOS MBR virus protection that may be enabled through the CMOS Setup. Boot the system from a floppy diskette containing FDISK, then run FDISK /MBR. This will overwrite the MBR and effectively remove EZ-Drive.

NOTE: The FDISK /MBR command is very powerful, and data on the drive may be lost. Be sure to make a complete backup of the drive’s contents before performing this procedure.

Symptom 35-22. You see an error message such as; "No IDE Drive Installed". EZ-Drive may not be reading the particular drive properly. Normally, EZ-Drive identifies an IDE drive even though the CMOS Setup may have no drive geometry information entered (or set to "auto-detect"). Occasionally, EZ-Drive reports that no IDE drive is installed - even when a drive is present. If CMOS has no values for the drive, it may inhibit the EZ-Drive setup. You should simply run the "auto-detect" feature of the BIOS before running EZ-Drive. A more reliable solution is often to insert the proper drive parameters into the CMOS Setup (i.e. heads, cylinders, sectors, and so on).

Symptom 35-23. You have trouble removing EZ-Drive from a system with available LBA support. There are actually two methods you can use to eliminate EZ-Drive from an LBA-compatible system. Before attempting either of these methods, make sure you are using EZ-Drive 5.00 or later:

• Insert the EZ-Drive diskette.
• Run EZ.
• Pick "Change Installed" features.
• ENABLE Windows NT Compatibility Mode for 5.00.

or;

• DISABLE Floppy Boot Protection for EZ 5.02 and later.
• Pick "Save Changes".
• Exit EZ-Drive.
• Boot system and enter CMOS Setup.
• "Auto-detect" hard drive or enter cylinders, sector, heads under User Definable Type.
• Enable LBA mode.
• Save changes and exit CMOS Setup.
• Boot system from a bootable floppy diskette (by-passing EZ-Drive).
• If all drives/directories are accessible, run the command FDISK/MBR to remove EZ-Drive MBR.
• If all drives/directories are NOT accessible, the BIOS LBA translation is different from the translation EZ-Drive used (in this case, the data must be backed up before proceeding).
• Boot directly from a floppy disk, run FDISK /MBR, then re-partition the drive with FDISK. Format the drive using FORMAT, then restore your data.

NOTE: The FDISK /MBR command is very powerful, and data on the drive may be lost. Be sure to make a complete backup of the drive’s contents before performing this procedure.

Symptom 35-24. You keep getting the message "Hold down the CTRL key...". In virtually all cases, the system has been infected with the "Ripper" virus. To correct the problem, try the procedure below (you will need EZ-Drive 5.00 or later):

• Boot directly from a floppy diskette.
• Insert the EZ-Drive diskette.
• Type EZ /MBR and press <Enter>.
• Run EZ.
• Pick "Change Installed" features.
• ENABLE Windows NT Compatibility Mode for 5.00.

or;

• DISABLE Floppy Boot Protection for EZ 5.02 and later.
• Pick "Save Changes".
• Run virus scan software.

Symptom 35-25. The system hangs after booting directly from non-system disk. A user turns on the machine with a diskette in the floppy drive that does not contain bootable system files. The message; "Non System Disk or Disk Error" is displayed on the screen. After the user removes the floppy and re-boots the system, it hangs and will not boot. All cases of this error have been linked to the "Antiexe" virus. To correct the problem, try the procedure below (you will need EZ-Drive 5.00 or later):

• Boot directly from a floppy diskette.
• Insert the EZ-Drive diskette.
• Type EZ/MBR and press <Enter>.
• Run EZ.
• Pick "Change Installed" features.
• ENABLE Windows NT Compatibility Mode for 5.00.

or;

• DISABLE Floppy Boot Protection for EZ 5.02 and later.
• Pick "Save Changes".
• Run virus scan software.

Symptom 35-26. You encounter an; "Unrecognized DBR" message from EZ-Drive. An unrecognized Disk Boot Record (DBR) message may mean that the DBR on the floppy diskette has been corrupted or simply is not one that is easily recognized by the program (i.e. a language-specific version of DOS). If the DBR is on a bootable floppy someone else has created, the first recommendation is to abort the boot process and SYS the diskette again such as:

SYS a:

If the DBR is on a DOS diskette like DOS Disk1, answer yes to complete the system transfer. If the hard drive refuses to boot (with a "Non-System Disk Error", reset the system and hold down the <Space> key. Insert a bootable floppy when prompted and press a key to get to an A: prompt. Then SYS the hard drive to transfer the bootable files. At that point, the hard drive should be able to boot without any problems.

Symptom 35-27. You cannot get EZ-Drive to work on some PS/1 and PS/2 systems. EZ-Drive will not work on micro-channel PCs.

Symptom 35-28. Windows 95 reports a problem with the MH32BIT.386 driver. The MH32BIT.386 driver should NOT be used with Windows 95 which already has all the support needed for EZ-Drive. Open the SYSTEM.INI file and comment out any references to the MH32BIT.386 driver.

Symptom 35-29. After removing EZ-Drive, the data on a hard drive is inaccessible. That is because; (1) the drive controller does not support large hard drives, or (2) the drive geometry entered into CMOS Setup is different than the configuration EZ-Drive had used. If the drive system does not support large hard drives, you must upgrade the drive controller or motherboard BIOS to support EIDE drives. If the drive system already supports EIDE, check the drive parameters entered in CMOS Setup, or try using the "auto-detect" feature in CMOS. If both of these options fail, you will need to repartition and reformat the drive, then restore the drive files from a backup.

Symptom 35-30. The <Alt> + <T> function was accidentally invoked under Disk Manager, and the DDO could not be recovered through EZ-Drive. Unfortunately, once the partition data on the first cylinder is wiped out, it cannot be recovered. You will have to reinstall the dynamic drive overlay (DDO), and restore the drive files from a backup.

Unlike Disk Manager or EZ-Drive which allow a system to use EIDE hard drives, Ontrack’s Drive Rocket is disk enhancement software which allows an IDE drive to transfer data in large "chunks". This speeds the transfer of data, and improves drive performance. Today’s hard drives allow for very fast and efficient data transfer, so Drive Rocket is no longer in popular use, but older systems and drives may still utilize Drive Rocket.

Symptom 35-31. When running Drive Rocket, the QEMM Stealth ROM feature indicates; "Disabling Stealth ROM", and then reports a reference to INT 76. The Stealth ROM feature is monitoring interrupts, and is disabling itself when Drive Rocket uses INT 13. You can disable the interrupt detection by adding the XSTI switch to the QEMM386 command line such as;

XSTI=76

This switch forces QEMM’s Stealth mode to ignore INT 76.

Symptom 35-32. During installation, Drive Rocket produces an error which says that it can't recognize the driver. There are some machines which simply will not support the Drive Rocket software because of the way Drive Rocket interacts with PC hardware. Do not manually over-ride a failed installation. Specific areas where Drive Rocket might fail are machines which already have a number of performance enhancement in place (i.e. a Pentium with PCI, LBA, or some other technology which is translating the drive parameters). When you see such an error, do not proceed with the Drive Rocket installation.

Symptom 35-33. You cannot remove Drive Rocket. Drive Rocket is called as a command line in CONFIG.SYS such as:

device=rocket.bin

To remove Drive Rocket, simply disable the command line. You should also delete the ROCKET.BIN file from the hard drive’s root directory.

Symptom 35-34. Drive Rocket refuses to identify the hard drive correctly. Some OEM versions of Drive Rocket (such as the version distributed by Western Digital) check for the presence of a particular hard drive. Drive Rocket starts by sending a query to the drive. If the response is anything other than the expected ID, Drive Rocket will produce an error message. Some sophisticated IDE cards will intercept queries and commands sent to the drive. This will cause Drive Rocket to believe there is no expected drive - even if there is. You should try to disable the BIOS on your controller, or format the drive using another controller card to avoid this problem. You could also install a non-OEM version of Drive Rocket.

Symptom 35-35. You have trouble loading Drive Rocket into high memory. Ideally, Drive Rocket can be loaded into the Upper Memory Area (UMA). However, there are reports of problems with the QEMM LOADHI statement loading Drive Rocket. Try using a different memory manager such as EMM386, or try loading other drivers into the UMA to free space in conventional memory for Drive Rocket.

Symptom 35-36. Drive Rocket reports a -35% increase. This typically occurs in contemporary, high-performance systems. It means that Drive Rocket is conflicting with some other driver or device, and is probably not a good choice for that particular computer. Remove the Drive Rocket command line from CONFIG.SYS, and delete ROCKET.BIN from the root directory.

Symptom 35-37. You encounter a GPF when working with the Control Panel in Windows 3.1x. You need to define the drives which contain Drive Rocket. Add a command line switch to the end of the line in CONFIG.SYS that calls the Drive Rocket driver. Add the following switch if Drive Rocket is on a primary and secondary drive;

/w=1,1

If Drive Rocket is only on the primary drive, use the command;

/w=1,

If Drive Rocket is only on the secondary drive, use the command;

/w=,1

That’s all for Chapter 35. Be sure to review the glossary and chapter questions on the accompanying CD. If you have access to the Internet, take a look at some of the Ontrack resources listed below:

MicroHouse: http://www.microhouse.com

Ontrack: http://www.ontrack.com