How to Disable Oplocks in a Windows 2000 Server

Disable oplocks from a console on your Windows 2000 server.

An opportunistic lock, or oplock, is a lock that a client places on a file that is located on a server. A client can then cache the file locally, which will reduce network traffic and improve response time for the client. Opportunistic locks are enabled by default on Windows Server 2000. The locks are a potential source for network file corruption. If you are concerned about network corruption due to oplocks, you can disable them in Windows Server 2000 by changing a value in the system registry.

Instructions

1. Press "Start" and click on "Run." Enter "Regedit" into the box. Click on "OK."

2. Browse the registry to the key named "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MRXSmb\Parameters\." Locate the subkey named "OplocksDisabled" in the right side of the Registry Editor. Double-click on the entry. Change the value to 1.

3. Navigate to the registry key "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters" in the left side of the window. Find the subkey named "EnableOplocks." Double-click on the subkey and set the value to 0.

4. Close the registry editor. Reboot the server to finalize changes to the registry.

Tips & Warnings

• Always back up the registry or create a system restore point before you modify registry values.

References

• Microsoft Support: Configuring Opportunistic Locking in Windows
• Data Access Worldwide: Opportunistic Locking and Read Caching on Microsoft Windows Networks