MS-DOS 6 Err Msg: Too Many Block Devices (97608)


The information in this article applies to:

  • Microsoft MS-DOS operating system 6.0
  • Microsoft MS-DOS operating system 6.2
  • Microsoft MS-DOS operating system 6.21
  • Microsoft MS-DOS operating system 6.22
  • Microsoft Windows 95
This article was previously published under Q97608
This information applies to both Microsoft DoubleSpace and Microsoft DriveSpace. For MS-DOS 6.22, use DRVSPACE in place of DBLSPACE for commands and filenames.

SYMPTOMS

You receive the following error message when you start your computer with MS-DOS 6.0 or later:
Too many block devices

CAUSE

If this message is displayed, one of the following conditions is occurring:

  • Too many block device drivers (for example, RAMDRIVE.SYS or a third-party block driver, such as a removable media driver) are being loaded from your CONFIG.SYS file.
  • One of your device drivers does not recognize the available drive letters.
  • You need to reconfigure your DoubleSpace-compressed drive(s).
  • You have an IBM 3363 optical drive conflict.
  • You manually removed MS-DOS DoubleSpace files (including your compressed volume file (CVF) and DBLSPACE.BIN) but did not delete the DBLSPACE.INI file.

MORE INFORMATION

This problem may occur more often if you are using DoubleSpace because DoubleSpace always allocates enough drive letters to reach from the last default block device to the letter specified by the LastDrive line in the DBLSPACE.INI file. If an additional block device is added after installing DoubleSpace, DoubleSpace attempts to preserve the quantity of available drives. Such attempts may increase the total number of drives beyond the 26 available drive letters.

DBLSPACE.SYS /MOVE Command Is Before a Block Device

If the DEVICEHIGH=C:\DOS\DBLSPACE.SYS /MOVE command in the CONFIG.SYS file is placed before the newly added block device (a device driver that uses a drive letter), the block device takes the next available drive letter after the LastDrive line in the DBLSPACE.INI file.

For example, if LastDrive is set to X and you add a block device after DEVICEHIGH=C:\DOS\DBLSPACE.SYS /MOVE, the block device is assigned the drive letter Y. If you add two more block devices after DEVICEHIGH=C:\DOS\DBLSPACE.SYS /MOVE, one becomes drive Z and the other causes the "Too many block devices" error message.

To correct this problem, run DoubleSpace and decrease the LastDrive statement. If DoubleSpace does not allow you to decrease the drive letter, you must edit the DBLSPACE.INI file manually. To do this, use the following steps:

  1. If you use Microsoft Windows and have a permanent swap file (PSF), run Windows, note the current size of your PSF, and then change your PSF to None. (You will undo this change later in this procedure.)
  2. Change to the host drive (for example, H).
  3. Use the ATTRIB command to change the file attributes on the DBLSPACE.INI file as in the following example:

    attrib h:\dblspace.ini -s -h -r

  4. Using a text editor, such as MS-DOS Editor, open the DBLSPACE.INI file and change the LastDrive setting to the letter you want to be the host drive.
  5. Change the first parameter in the ActivateDrive line to the same letter you used in step 3.

    WARNING: Do not change the second parameter, which is (represented by <xx>) in the following example: 
          Before change:     ActivateDrive=X,<xx>
      After change:      ActivateDrive=N,<xx>
    WARNING: If you use a drive letter that is used by a physical device (such as drive A) for the N value, the system may stop responding (hang) or continually reboot when you restart it.
  6. Save your changes and quit the text editor.
  7. Reset the System, Hidden, and Read-Only attributes on the DBLSPACE.INI file as in the following example:

    attrib h:\dblspace.ini +s +h +r

  8. Restart your computer by pressing CTRL+ALT+DEL.
  9. If you removed your PSF in step 1, run Windows and re-create the PSF on your host drive. Do not attempt to create the PSF on your DoubleSpace-compressed drive. You may receive the following message if you re-create your PSF at its previous size:

    Windows will not use more than the virtual memory specified by the Recommended Size. Are you sure you want to create a larger swap file?

    You can ignore this error message; it is probably incorrect. As long as the PSF is not larger than four times your physical memory, Windows can use a swap file that is larger than the recommended size.

DBLSPACE.SYS /MOVE Command Is After a Block Device

If the DEVICEHIGH=C:\DOS\DBLSPACE.SYS /MOVE command in the CONFIG.SYS file is placed after the newly added block device (a device driver that uses a drive letter), the block device takes the next available drive letter after the last physical block device (for example, the last hard disk drive partition), and pushes the available drive letters for DoubleSpace beyond the value specified in the DBLSPACE.INI file LastDrive statement.

For example, DBLSPACE /LIST reports drive Y as being available for DoubleSpace's use when the DBLSPACE.INI file reports LastDrive=X. If your last logical drive is C and you add one block device before DEVICEHIGH=C:\DOS\DBLSPACE.SYS /MOVE. The block device becomes drive D. If you add two more block devices, then one of them becomes E and the other causes MS-DOS to display the "Too many block devices" error message.

To correct this problem, use the same procedure in the previous section.

You Have an IBM3363 Optical Drive Conflict

After you run DoubleSpace on an IBM PS/2 with a 3363 optical drive, you may receive the error message "Too many block devices" when the ECYDDX.SYS device driver in loaded from the CONFIG.SYS file. As a result, the DoubleSpace drive letter mapping may shift and the LastDrive= and FirstDrive= settings in the DBLSPACE.INI file may be changed.

To work around this problem, change the drives reserved by ECYDDX.SYS by adding the DRIVES=<n> parameter to the ECYDDX.SYS command in the CONFIG.SYS file (where <n> is the number of drives).

NOTE: IBM3363.EXE is used in place of MSCDEX.EXE with this drive.

ECYDDX.SYS is a device driver used with the IBM 3363 optical drive. This driver is used in conjunction with IBM3363.EXE to provide access to the IBM 3363 optical drive. By default, the ECYDDX.SYS driver reserves eight drives on a PS/2 and one drive on a PS/1. These reserved drives behave like block devices and take the next available drive letters when loading.

NOTE: This may also apply to the IBM PC/Support program and its driver, FSDDX.SYS. By default, FSDDX.SYS allocates eight drives and may need the DRIVES=<n> parameter added.

You Manually Removed MS-DOS DoubleSpace files (Including Your Compressed

Volume File (CVF) and DBLSPACE.BIN), but Did Not Delete DBLSPACE.INI

To work around this problem, delete DBLSPACE.INI. If you have removed all your DoubleSpace drives, type the following at the MS-DOS command prompt and then press ENTER:

deltree c:\dblspace.ini /y

For more information about block devices and DoubleSpace, query on the following words in the Microsoft Knowledge Base:

how doublespace assigns drive letters

Modification Type:MajorLast Reviewed:12/18/2000
Keywords:KB97608
©2002 Microsoft Corporation. All rights reserved.