MS-DOS Err Msg with DoubleSpace: Insufficient Disk Space

• Microsoft MS-DOS operating system versions 6.0, 6.2, 6.21, 6.22

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.

SUMMARY

When you copy or create files on a DoubleSpace-compressed drive, it is possible to receive an "Insufficient Disk Space" error message when MS-DOS reports sufficient space to perform the operation. This article discusses potential causes of this problem and workarounds.

MORE INFORMATION

There are several instances, including those listed below, in which MS-DOS may report insufficient disk space when copying files to a compressed drive.

• The estimated compression ratio (ECR) is lower than the actual compression ratio (ACR) for the files to be copied. In this case, MS-DOS underestimates the space available. To correct this problem, set the ECR equal to the ACR for the drive as follows:

  1. Start DoubleSpace by typing "dblspace" (without the quotation

        marks) at the MS-DOS command prompt.
  

  2. Select the compressed drive you want to change and then choose the

        Change Ratio command from the Drive menu.
  

        The Change Compression Ratio dialog box appears.
  

  3. The default ratio is the ACR. Choose OK.

  You can also change the ECR from the MS-DOS command prompt. For more information, type "help dblspace /ratio" (without the quotation marks) at the MS-DOS command prompt.

  NOTE: The above procedure causes MS-DOS to estimate free disk space more accurately and may also increase the number of FAT entries available. If the files to be copied are highly compressible, then you may need to make the ECR higher than the current ACR.

• The ECR is higher than the ACR for the files to be copied. In this case, MS-DOS overestimates the space available, and you must either delete files or enlarge the drive to free space. To enlarge the compressed drive, use the following steps:

  1. Start DoubleSpace by typing "dblspace" (without the quotation

        marks) at the MS-DOS command prompt.
  

  2. Select the compressed drive you want to enlarge, then choose the

        Change Size command from the Drive menu.
  

        The Change Size dialog box appears. The New Free Space line shows
        how much free space the compressed and uncompressed drives will
        have if you choose OK.
  

  3. Specify a smaller number for New Free Space on the uncompressed

        drive. As you change this number, DoubleSpace adjusts the New Free
        Space amount for the compressed drive. When the New Free Space amount
        for both drives is what you want, choose OK.
  

  DoubleSpace enlarges the compressed drive.

  NOTE: The above procedure decreases the free space on the uncompressed (host) drive.

• The DoubleSpace drive is too fragmented. To correct this problem, use the commands DBLSPACE /DEFRAG /F and DBLSPACE /DEFRAG on the compressed drive as follows:

  NOTE: You may want to perform this procedure overnight. Defragmenting a large or badly fragmented drive can take a long time. (To defragment overnight, put both commands into a batch file.)

  1. Make the compressed drive your current drive.

  2. Type "dblspace /defrag /f" (without the quotation marks) at the

        MS-DOS command prompt.
  

  DoubleSpace defragments the drive.

  3. When DoubleSpace finishes, type "dblspace /defrag" (without the

        quotation marks) at the MS-DOS command prompt.
  

  DoubleSpace consolidates free space on the drive to leave as much free space as possible.

• No more FAT entries are available. To correct this problem, split the host drive into more compressed drives as follows:

• Finally, certain programs or files may cause the "Insufficient Disk Space" message or may fail when they are installed on a DoubleSpace- compressed drive because their ACR is close to 1:1. These include the following:

  - Many games by Sierra On-Line (also marketed as Dynamix or Coktel)

  - Microsoft Mail Format (.MMF) files

  - Encrypted data files

  - Precompressed files (such as .ARC, .ZIP, .PCX, and .GIF files)

For more information on the ECR, ACR, and the space available on a DoubleSpace-compressed drive, see page 125 in the "User's Guide."

The products included here are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.

REFERENCES

"Microsoft MS-DOS User's Guide" for version 6 and 6.2, pages 125-126

README.TXT, Section 7.3