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Q111908: DoubleSpace Err Msg: DBLSPACE.<nnn> Is Not a Valid CVF

Article: Q111908
Product(s): Microsoft Disk Operating System
Version(s): MS-DOS:6.2
Operating System(s): 
Keyword(s): 
Last Modified: 21-NOV-1999

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The information in this article applies to:

- Microsoft MS-DOS operating system version 6.2 
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SYMPTOMS
========

ScanDisk repairs an error in the Microsoft DoubleSpace BIOS Parameter Block
(MDBPB), or does not find any errors, when examining a compressed volume file
(CVF); however, DoubleSpace is unable to mount the CVF and displays the
following error

  DoubleSpace cannot mount drive <x>.
  The <y>:\DBLSPACE.<nnn> file is not a valid compressed volume
  file.
  To fix it, type SCANDISK <y>:\DBLSPACE.<nnn> at the command
  prompt.

where <x> is the drive letter of the CVF when mounted, <y> is the
host drive, and <nnn> is the CVF's sequence number (extension). You do not
have access to the files on the compressed drive.

STATUS
======

There may be rare instances of CVF corruption that ScanDisk cannot correct.
Microsoft is researching this problem and will post new information in the
Microsoft Knowledge Base as it becomes available.

CAUSE
=====


WORKAROUND
==========

If you are using MS-DOS 6.2, and your CVF was not created with a beta version of
MS-DOS 6.0, contact Microsoft Product Support Services for assistance in
resolving this problem.


NOTE: If your CVF was created with a beta version of MS-DOS 6.0, you need to
remove the DoubleSpace CVFs, and then install an MS-DOS 6.x Upgrade. You will
not be able to backup the data on the damaged CVF in this case.


IMPORTANT: If you have the above symptoms and are running MS-DOS 6.0, upgrade to
MS-DOS 6.2 and use ScanDisk to repair the CVF. ScanDisk can correct most
instances of CVF corruption that prevent DoubleSpace from mounting the volume.


MORE INFORMATION
================

To access the files on a compressed drive or CVF, DoubleSpace must mount the
CVF. While ScanDisk can correct most problems that prevent DoubleSpace from
mounting a CVF, there may be rare cases of CVF corruption that ScanDisk cannot
repair.

REFERENCES
==========

"Microsoft MS-DOS 6 Programmer's Reference"

Additional query words: 6.22 6.20 tshoot invalid damaged

======================================================================
Keywords          :  
Technology        : kbMSDOSSearch kbMSDOS620
Version           : MS-DOS:6.2

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