Windows Runs Slowly Performing Large Backup Operation (224073)

SYMPTOMS

While you are backing up a very large number of files to a tape drive or other large-capacity device, or you are comparing an existing backup set to the original files on the hard disk, Windows may begin to run slowly.

This problem is confirmed to occur when you back up a large number of files (2,000-3,000 or more files) if the backup software is configured to perform a comparison between the backed-up files on the tape drive and the original files on the hard disk after the files are backed up. This problem may also occur when you are comparing a set of files that was backed up previously.

CAUSE

This behavior is caused by an error in the Windows 98 protected-mode disk cache (Vcache.vxd). The error occurs when the maximum value of a variable used in tracking the age of blocks in the cache is exceeded. If this occurs while the protected-mode disk cache is attempting to free the oldest blocks to make room for new data, it takes a long time for the operation to finish. Once this condition occurs, Windows runs slowly, and continues to do so until the computer is restarted.

RESOLUTION

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that are experiencing this specific problem.

To resolve this problem, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix should have the following file attributes or later:

   Date     Time      Version     Size     File name     Platform
   --------------------------------------------------------------
   4/7/99   12:07pm   4.10.2183   37,183   Vcache.vxd    Win98

MORE INFORMATION

This problem has been reported to occur with the following third-party products:

Onstream 30-GB Digital Drive

However, this problem is not caused by these products, and could also occur with other high-capacity tape backup hardware and backup software.

For additional information about Windows 98 and Windows 98 Second Edition hotfixes, click the article number below to view the article in the Microsoft Knowledge Base: