XCOPY Results in Data Loss When Copying Extremely Large Files (124854)

The information in this article applies to:
    Microsoft MS-DOS operating system 5.0
    Microsoft MS-DOS operating system 6.0
    Microsoft MS-DOS operating system 6.2
    Microsoft MS-DOS operating system 6.21
    Microsoft MS-DOS operating system 6.22

This article was previously published under Q124854


Running the XCOPY command results in data loss when you try to copy a 15-megabyte (MB) or larger file, such as a compressed volume file (CVF) or Microsoft Mail folder (MMF).


Microsoft has confirmed this to be a problem in MS-DOS versions 5.00, 6.00, 6.20, 6.21, and 6.22. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.


When you use XCOPY to copy a file 15 MB or larger to another location on the same drive and that drive has insufficient disk space to do so, XCOPY eventually reports that there is insufficient disk space, and that no files were copied. However, the results of a DIR command indicate a new file was created--and that it takes up approximately the amount of free disk space that existed before you ran XCOPY. The directory listing also shows that the original file was deleted and that the system now has the same amount of free disk space as the original file occupied before running XCOPY.

Modification Type: Major Last Reviewed: 11/19/1999
Keywords: KB124854