Large Number of Mounts/Dismounts on an NTFS Partition Causes a Memory Leak

• Microsoft Windows NT Workstation version 4.0
• Microsoft Windows NT Server version 4.0
• Microsoft Windows NT Server, Enterprise Edition version 4.0

SYMPTOMS

A system may leak nonpageable memory when a large amount of mounts and dismounts are done on an NTFS partition.

CAUSE

The driver Ntfs.sys does not keep track of a VPB structure if a dismount request is followed by an unlock request. The memory leak is small, so the problem will usually appear after a period of days. POOLMON can be used to check this problem. Look for the NtfV tag taking up a lot of the nonpageable memory. Performance Monitor can also be used to monitor nonpageable memory use.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.0. This problem was first corrected in Windows NT version 4.0 Service Pack 5.

Additional query words: 4.00

Keywords          : kbbug4.00 kbfix4.00 nt4sp5fix 
Version           : WinNT:4.0
Platform          : winnt 
Issue type        : kbbug 

Last Reviewed: July 7, 1999