ScanDisk Reports Compressed Floppy Too Full for Undo (107711)

The information in this article applies to:
    Microsoft MS-DOS operating system 6.2

This article was previously published under Q107711


When ScanDisk finds errors, it prompts you to create an Undo disk before correcting the errors. (You also have the option to skip the Undo disk step.) If you choose to create an Undo disk, you must save the information to a floppy disk. If you insert a disk that has been compressed by DoubleSpace, the following message may appear

The disk in drive <x> is too full to be used as an Undo disk. To ensure that there is enough room for all the Undo information, make sure the floppy disk has at least 300,000 bytes of free space.
where drive <x> is the DoubleSpace-compressed floppy disk.


ScanDisk cannot mount a compressed disk for use as the Undo disk, even if Automount is enabled in DoubleSpace Manager.


Before you run ScanDisk, be sure the potential Undo disk is mounted. The compressed floppy disk must be inserted in the disk drive prior to starting ScanDisk. Any action (such as DIR or CHKDSK) you run on that floppy disk drive causes the system to mount the disk. ScanDisk then recognizes the compressed free space on that disk.


This situation does not occur in MS-DOS version 6.22. DriveSpace functionality was enhanced to correctly deal with ScanDisk Undo disk.

Modification Type: Major Last Reviewed: 11/25/1999
Keywords: KB107711