Microsoft KB Archive/824909

= Deadlock condition may occur when a large number of DFS clients connect to a shared folder for the first time =

Article ID: 824909

Article Last Modified on 7/24/2007

-

APPLIES TO


 * Microsoft Windows Server 2003, Standard Edition (32-bit x86)
 * Microsoft Windows Server 2003, Enterprise Edition (32-bit x86)
 * Microsoft Windows Server 2003, Enterprise x64 Edition

-





SYMPTOMS
When many Distributed File System (DFS) clients connect to a server and access a shared folder for the first time, you may find that a deadlock condition occurs in the server message block (SMB) redirector component or in the Terminal Services redirector component. Therefore, the server does not return a referral to the DFS client, and the DFS client cannot connect to the shared folder.

For example, a deadlock condition in the Terminal Services redirector component may result when many DFS clients connect to the server in a Terminal Services session and access different \\ \ shares, where an entry does not exist for any one of the shares in the DFS referral cache.



CAUSE
This problem may occur if both the following conditions are true:
 * The number of network file access requests is larger than the number of available critical worker threads.
 * The network file access requests are for \\ \ shares that are accessed by the DFS client for the first time. That is, share entries do not exist in the DFS referral cache.

The DFS client (Mup.sys) posts network file access requests to the critical work queue on the server. Because the DFS client does not throttle work items, a deadlock condition may occur in situations where the redirector components require worker threads to complete the transport connection operations, and the worker threads are exhausted by the DFS client.



RESOLUTION
To resolve this issue, obtain the latest service pack for Windows Server 2003.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

889100 How to obtain the latest service pack for Windows Server 2003

Hotfix information
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

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

Prerequisites
This hotfix requires Windows Server 2003.

Restart requirement
You must restart your computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Date        Time   Version      Size     File name --- 22-Jul-2003 19:10  5.2.3790.71  106,496  Mup.sys 22-Jul-2003 18:58  5.2.3790.71  304,640  Mup.sys  IA-64



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section of this article. This problem was corrected in Windows Server 2003 Service Pack 1.



MORE INFORMATION
For more information about DFS in Windows Server 2003, visit the following Microsoft Web site:

http://technet2.microsoft.com/windowsserver/en/library/20ffb860-f802-455c-9ca2-5194f79a9eb41033.mspx

Keywords: kbhotfixserver kbqfe kbbug kbfix kbqfe kbwinserv2003presp1fix KB824909

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.