Contents of the Offline Files Folder Do Not Maintain Compression on NTFS Partitions (227332)


The information in this article applies to:

  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional
  • Microsoft Windows 2000 Datacenter Server
This article was previously published under Q227332

SYMPTOMS

Manually compressing the Offline Files cache\database (the %SystemRoot%\CSC folder) works, and files currently stored in the cache are compressed, but newly cached files are not stored in compressed format and previously compressed files become uncompressed after synchronization.

CAUSE

Offline file compression is not directly supported by Offline Files. Windows 2000 writes files in uncompressed format even if the folder is marked for compression. This ensures that a deadlock situation does not occur. Marking the CSC (Client Side Caching) folder to be compressed and leaving it this way can cause a variety of complications ranging from caching update problems to Windows 2000 not responding (hanging) while attempting to access files residing within the cache.

RESOLUTION

To prevent this problem from occurring, do not compress the Offline Files cache/database (the CSC folder).

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

If the CSC folder is specifically marked to be compressed, file system calls are made by CSC to ensure that the files get marked as uncompressed. This is done each time a file is accessed within the database.

Note that the Offline Files cache\database is hidden by default and cannot be compressed except by an administrator, and should not be directly accessed in such a manner. Doing so may cause the cache to become corrupted. Under typical conditions, a file that currently resides within the cache as compressed is uncompressed after a synchronization update if the file has changes that are written back to the cache.

The most common issue that results from compressing the CSC folder is a client computer hanging while attempting to access a cached document while offline.
Modification Type:MajorLast Reviewed:11/21/2003
Keywords:kbenv kbprb KB227332
©2003 Microsoft Corporation. All rights reserved.