DIR /C Returns Compression Ratio for Uncompressed Files

• Microsoft Windows 95
• Microsoft Plus! for Windows 95

SYMPTOMS

When you use the DIR /C or DIR /CH command on a volume that is compressed with DriveSpace 3.0, a compression ratio may be returned for files that have not been compressed. The ratio may be as high as 64:1.

CAUSE

The DIR /C command displays the compression ratio of a file, assuming that the file is located on a drive using 8K clusters. This command returns an estimated compression ratio for all files, regardless of their compression status, as if they were compressed on a drive with 8K clusters.

The DIR /CH command may return a more accurate value if the cluster size is not 8K, as it references the cluster size of the host partition for its estimates. However, this command also returns an estimated compression ratio for all files saved to the drive.

MORE INFORMATION

Microsoft Plus! for Windows 95 installs DriveSpace 3.0 and System Agent by default unless you choose not to.

You can save uncompressed files to a compressed volume when the No Compression option is selected for the drive.

You can configure the Compression Agent with System Agent to compress the files at a later time. This configuration maximizes system performance by delaying the compression of files written to the drive until the computer is idle.

STATUS

Microsoft has confirmed this to be a problem with Microsoft Plus! for Windows 95. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.