Microsoft KB Archive/101240

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DBLSPACE Msg: Drive X Already Has an Estimated Compression...

Article ID: 101240

Article Last Modified on 11/22/1999


  • Microsoft MS-DOS 6.0 Standard Edition
  • Microsoft MS-DOS 6.2 Standard Edition
  • Microsoft MS-DOS 6.22 Standard Edition

This article was previously published under Q101240


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.

When you have a DoubleSpace-compressed drive that is less than 25 percent full, the DBLSPACE /RATIO command results in the following error message:

DoubleSpace is examining drive <drive letter>.
Drive <drive letter> already has an estimated compression ratio of nn.n to 1.

If the drive is less than 25 percent full, you can set the estimated compression ratio (ECR) manually, but DoubleSpace cannot set the ECR equal to the actual compression ratio (ACR).


DBLSPACE /RATIO adjusts the ECR to the ACR, unless the DoubleSpace drive is less than 25 percent full.

When a drive is less than 25 percent full, the data contained in it may not be representative of the data the drive will eventually hold. Therefore, on average, it is better to maintain a 2:1 compression ratio until the drive is 25 percent full.

In some cases, if the ECR is set to a low value, the ratio is adjusted when you run DBLSPACE /RATIO. However, if the ECR is then set to a high value, the ratio is not adjusted because by setting the ECR higher, the space used falls below 25 percent. Subsequent use of the DBLSPACE /RATIO command results in the message noted above.

Additional query words: 6.00 % double space 6.20

Keywords: KB101240