1001 Secrets for Windows NT Registry
(Publisher: 29th Street Press)
Author(s): Tim Daniels
ISBN: 1882419685
Publication Date: 12/01/97

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This value sets the minimum network throughput, in kilobytes per second, before Lanmanager Workstation enables the read-ahead function. The default value is -1.

Lanmanager Server

Lanmanger Server is Microsoft’s implementation of an SMB (Server Message Block) file server. It is a focal point of performance tuning for any file-sharing server.

VI-16 If you frequently get “server paged” or “server nonpaged” errors in Performance Monitor, you are seeing Lanmanager Server running out of memory that it’s allocated for itself. You may want to raise these values to give Lanmanager Server more memory; however, giving these memory resources to Lanmanager keeps other system drivers and applications from using them. To give Lanmanager more paged and nonpaged memory, change the registry entries below.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\LanmanServer\ Parameters
Value Name: MaxNonPagedMemoryUsage
Data Type: REG_DWORD
Value: 0

VI-17 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\LanmanServer\ Parameters
Value Name: MaxPagedMemoryUsage
Data Type: REG_DWORD
Value: 0

These values set the number of megabytes allocated by Lanmanager Server for nonpaged and paged memory. The default, which is determined internally, is 0.

VI-18 By default, Lanmanager Server’s worker threads run at one priority level higher than typical application threads. If network throughput is low because the Server’s threads are competing with other threads for processor time, you may want to change this registry entry to increase the priority boost.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\LanmanServer\ Parameters
Value Name: ThreadPriority
Data Type: REG_DWORD
Value: 1

Valid values are 0, 1, or 2, which determine how many levels above normal priority Lanmanager’s worker threads run; and 15, which makes Lanmanager Server’s threads run at real-time priority. Increasing the priority may reduce the responsiveness of other applications and services on the machine, especially if you set it to real-time priority.

VI-19 When the server maintains extra pre-initialized end-points, establishing new connections takes less processing. This value sets the number of end-points the server maintains.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\LanmanServer\ Parameters
Value Name: MinFreeConnections
Data Type: RED_DWORD
Value: 2

Valid values range from 2 to 5; the default is determined internally. You can reduce the value to minimize idle memory overhead when the memory resources on the system are in high demand.

VI-20 If memory resources are scarce or if you want to limit the total number of users that can simultaneously log on to the server, change this registry entry.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\LanmanServer\ Parameters
Value Name: Users
Data Type: REG_DWORD
Value: <number>

The value is the number of users who can long on to the server simultaneously.

VI-21 Every time a connection is made to Lanmanager Server, resources are allocated to service it. Sometimes idle connections tie up resources for a long time. To free resources sooner, change this registry entry.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\LanmanServer\ Parameters
Value Name: AutoDisconnect
Data Type: REG_DWORD
Value: 15

This value specifies the number of minutes a connection can be idle before it is automatically disconnected and the resources associated with it are freed. The default value is 15. Reducing this value can keep resource usage to a minimum, but it’s possible to incur additional overhead if clients reconnect after their connections are dropped.

VI-22 The registry entry below tells Lanmanager Server to allocate work items for processing raw SMBs (Server Message Blocks).

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\LanmanServer\ Parameters
Value Name: EnableRaw
Data Type: REG_DWORD
Value: 1

Setting this value to 1 (the default) enables support for raw SMBs, and performance improves. Setting this value to 0 disables support.

Opportunistic locking is a performance-enhancing protocol Windows NT file systems use to detect remote machines’ modifications to shared files and directories. Enabling op-locks can cause you to lose cached data if the system fails.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\LanmanServer\ Parameters
Value Name: EnableOpLocks
Data Type: REG_DWORD
Value: 1

The default value is 1, which enables op-locking. Change the value to 0 to disable this feature.


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