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Q102981: REG: Workstation Service Entries

Article: Q102981
Product(s): Microsoft Windows NT
Version(s): 3.1
Operating System(s): 
Keyword(s): kbother
Last Modified: 28-FEB-2002

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows NT Server version 3.1 
- Microsoft Windows NT Workstation version 3.1 
- Microsoft Windows NT Advanced Server, version 3.1 
-------------------------------------------------------------------------------

WORKSTATION SERVICE ENTRIES
---------------------------

You can modify the startup parameters for the Workstation service using the
Registry Editor. Unless otherwise indicated, these value entries are found
in the following Registry path:

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet
  \Services\LanmanWorkstation\Parameters

The parameters that control network bindings for this service are described
in the article "NetRules Subkey Entries".

BufFilesDenyWrite   REG_DWORD   0 or 1
--------------------------------------

Default: 1 (true)

Specifies whether the redirector should cache files that are opened with
only FILE_SHARE_READ sharing access. Usually, if a file is opened with
FILE_SHARE_READ specified, the file cannot be buffered because other
processes may also be reading that file. This optimization allows the
redirector to buffer such files. This optimization is safe because no
process can write to the file.

Disable this parameter if it is necessary to preserve the strict semantics
of the sharing modes specified.

BufNamedPipes   REG_DWORD   0 or 1
----------------------------------

Default: 1 (true)

Indicates whether the redirector should buffer character-mode named pipes.

Disable this parameter to guarantee that all pipe write operations are
flushed to the server immediately and to disable read ahead on character-
mode named pipes.

BufReadOnlyFiles   REG_DWORD   0 or 1
-------------------------------------

Default: 1 (true)

...\CurrentControlSet\Services\LanmanWorkstation
Specifies whether the redirector should cache files that are read-only.
Usually, if a read-only file is opened, the file cannot be buffered because
other processes may also be reading that file. This optimization allows the
redirector to buffer such files. This optimization is safe because no
process can write to the file. However, another user can modify the file to
enable writing to the file, causing loss of data. Disable this parameter if
it is necessary to preserve the strict semantics of the sharing modes
specified.

CacheFileTimeout   REG_DWORD   Number of seconds
------------------------------------------------

Default: 10

Specifies the maximum time that a file will be left in the cache after the
application has closed the file.

Increase the value of this parameter if you are performing operations on
the server that could cause files to be reopened more than 10 seconds after
the application has closed them. For example, if you are performing a build
over the network, you should increase this parameter's value.

CharWait   REG_DWORD   0 to 65535 milliseconds
----------------------------------------------

Default: 3600

Specifies time to wait for an instance of a named pipe to become available
when opening the pipe. Increase this value if your pipe server application
is typically very busy.

CollectionTime   REG_DWORD   0 to 65535000 milliseconds
-------------------------------------------------------

Default: 250

Specifies the maximum time that write-behind data will remain in a
character-mode pipe buffer. Changing this value may cause a named pipe
application's performance to improve (but it does not affect SQL Server
applications).

DormantFileLimit   REG_DWORD   Number of files
----------------------------------------------

Default: 45

Specifies the maximum number of files that should be left open on a share
after the application has closed the file. This parameter exists because
the default configuration of LAN Manager servers only allow a total of 60
open files from remote clients and 50 from each client workstation. Because
the Windows NT redirector may keep files open in the cache after an
application has closed the file, this means that the redirector may
overload a misconfigured LAN Manager server. To correct this problem,
either reduce this value, or increase the values for the LAN Manager
server's maxSessopens and maxOpens parameters.

IllegalDatagramResetTime   REG_DWORD   Number of seconds
--------------------------------------------------------

Default: 60

Specifies the span of time during which the number of illegal datagram
events is counted. Because Windows NT logs all illegal datagrams, it is
possible for the event log to be filled with a proliferation of these in a
short amount of time. This entry and the NumIllegalDatagramEvents entry
work together to limit the number of illegal datagrams that are recorded in
the log within a certain span of time.

KeepConn   REG_DWORD   1 to 65535 seconds
-----------------------------------------

Default: 600

Specifies the maximum amount of time that a connection can be left dormant.
This parameter is the redirector equivalent of the Disc parameter in the
Services\LanmanServer\Parameters subkey.

As a general rule, try increasing this value if your application closes and
opens UNC files to a server less frequently than 10 minutes apart. This
decreases the number of reconnections made to a server.

LockIncrement   REG_DWORD   Number of milliseconds
--------------------------------------------------

Default: 10

This parameter is not used for Win32 applications. However, if OS/2-based
applications request that a lock operation waits forever, and if the lock
cannot be immediately granted on a non-LAN Manager version 2.0 server, this
parameter controls the rate at which the redirector ramps back the failed
lock operations.

This parameter should not be changed unless you are running an OS/2-based
application that requests lock operations that might fail.

LockMaximum   REG_DWORD   Number of milliseconds
------------------------------------------------

Default: 500

Used to configure the lock backoff package. This parameter exists to
prevent an errant application from "swamping" a server with nonblocking
requests where there is no data available for the application.

LockQuota   REG_DWORD   Bytes of data
-------------------------------------

Default: 4096 (bytes)

Specifies the maximum amount of data that is read for each file using this
optimization if the UseLockReadUnlock parameter is enabled. Increase this
value if your application performs a significant number of lock-and-read
style operations. (This means performing lock operations and immediately
reading the contents of the locked data.) It is conceivable that you could
cause the system to run out of paged pool, but only by increasing this
value to a few megabytes and by using an application that locks millions-of-
byte ranges.

LogElectionPackets   REG_DWORD   0 or 1
---------------------------------------

Default: 0 (false)

Specifies whether the Browser should generate events when election packets
are received.

MailslotBuffers   REG_DWORD   Number of buffers
-----------------------------------------------

Default: 5

Specifies the maximum number of buffers available to process mailslot
messages. If your application uses many mailslot operations, set this
higher to avoid losing mailslot messages.

MaxCmds   REG_DWORD   0 to 255
------------------------------

Default: 15

Specifies the maximum number of work buffers that the redirector reserves
for performance reasons. Increase this value to increase your network
throughput. If your application performs more than 15 simultaneous
operations, you might want to increase this value. Because this parameter
actually controls the number of execution threads that can be simultane
usly outstanding at any time, your network performance will not always be
improved by increasing this parameter. Each additional execution threads
takes about 1K of nonpaged pool if you actually load up the network.
Resources will not be consumed, however, unless the user actually makes use
of them.

MaxCollectionCount   REG_DWORD   0 to 65535 bytes
-------------------------------------------------

Default: 16

Specifies the threshold for character-mode named pipes writes. If the write
is smaller than this value, the write will be buffered. Adjusting this
value may improve performance for a named-pipe application (but it will not
affect SQL server applications).

NumIllegalDatagramEvents   REG_DWORD   Number of events
-------------------------------------------------------

Default: 5

Specifies the maximum number of datagram events to be logged within the
span of time specified by the IllegalDatagramResetTime parameter. Because
Windows NT logs all illegal datagrams, the event log can be filled with a
proliferation of these in a short time. This entry and the
IllegalDatagramResetTime entry work together.

OtherDomains   REG_SZ   DomainNames
-----------------------------------

Default: (none)

Specifies the Microsoft LAN Manager domains to be listed for browsing.

PipeIncrement   REG_DWORD   Number of milliseconds
--------------------------------------------------

Default: 10

Controls the rate at which the redirector "backs off" on failing
nonblocking pipe reads.

This parameter is used to prevent an errant application from swamping a
server with nonblocking requests where there is no data available for the
application. You can use the backoff statistics to tune this parameter to
be more efficient for an application that uses nonblocking named pipes
(except for SQL Server applications).

PipeMaximum   REG_DWORD   Number of milliseconds
------------------------------------------------

Default: 500

Controls the maximum time at which the redirector "backs off" on failing
non-blocking pipe reads.

This parameter exists to prevent an errant application from swamping a
server with nonblocking requests where there is no data available for the
application. You can use the backoff statistics to tune this parameter to
be more efficient for an application that uses nonblocking named pipes
(except for SQL Server applications).

ReadAheadThroughput   REG_DWORD   Kilobytes per second
------------------------------------------------------

Default: 0xffffffff

Specifies the throughput required on a connection before the cache manager
is told to enable read ahead.

ServerAnnounceBuffers   REG_DWORD   Number
------------------------------------------

Default: 20

Specifies the maximum  buffers used to process server announcements. If
your network has many servers, you can increase this value to avoid losing
server announcements.

This parameter is found under the LanmanWorkstation\Parameters\Static
subkey.

SessTimeout   REG_DWORD   10 to 65535 seconds
---------------------------------------------

Default: 45

Specifies the maximum amount of time that the redirector allows an
operation that is not long-term to be outstanding.

SizCharBuf   REG_DWORD   64 to 4096 bytes
-----------------------------------------

Default: 512

Specifies the maximum number of bytes that will be written into a character-
mode pipe buffer. Adjusting this value may improve performance for a named-
pipe application (but it will not affect SQL server applications).

Transports   REG_MULTI_SZ   List
--------------------------------

Default: None

Lists the transports that the redirector services and is found under the
LanmanWorkstation\Linkage subkey. You should modify it by choosing the
Network icon in Control Panel.

Use512ByteMaxTransfer   REG_DWORD   0 or 1
------------------------------------------

Default: 0 (false)

Specifies whether the redirector should only send a maximum of 512 bytes in
a request to an MS-Net server regardless of the servers-negotiated buffer
size. If this parameter is disabled, request transfers from the Windows NT
redirector could cause the MS-Net server to crash.

UseLockReadUnlock   REG_DWORD   0 or 1
--------------------------------------

Default: 1 (true)

Indicates whether the redirector uses the lock-and-read and write-and-
unlock performance enhancements.

When this value is enabled, it generally provides a significant performance
benefit. However, database applications that lock a range and don't allow
data within that range to be read will suffer performance degradation
unless this parameter is disabled.

UseOpportunisticLocking   REG_DWORD   0 or 1
--------------------------------------------

Default: 1 (true)

Indicates whether the redirector should use opportunistic-locking (oplock)
performance enhancement. This parameter should be disabled only to isolate
problems.

UseRawRead   REG_DWORD   0 or 1
-------------------------------

Default: 1 (true)

Enables the raw-read optimization. This provides a significant performance
enhancement on a local area network

UseRawWrite   REG_DWORD   0 or 1
--------------------------------

Default: 1 (true)

Enables the raw-write optimization. On a LAN, this provides a significant
performance enhancement.

UseUnlockBehind   REG_DWORD   0 or 1
------------------------------------

Default: 1 (true)

Indicates whether the redirector will complete an unlock operation before
it has received confirmation from the server that the unlock operation has
completed. Disable this parameter only to isolate problems or to guarantee
that all unlock operations complete on the server before completing the
application's unlock request.

UseWriteRawData   REG_DWORD   0 or 1
------------------------------------

Default: 1 (true)

Enables the raw-write-with-data optimization. This allows the redirector to
send 4 KB of data with each write-raw operation. This provides a
significant performance enhancement on a local area network.

UtilizeNtCaching   REG_DWORD   0 or 1
-------------------------------------

Default: 1 (true)

Indicates whether the redirector uses the cache manager to cache the
contents of files. Disable this parameter only to guarantee that all data
is flushed to the server immediately after it is written by the
application.

Reference: "The Windows NT Resource Kit for Operating System Version 3.1".

Additional query words: prodnt

======================================================================
Keywords          : kbother 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW310 kbWinNTSsearch kbWinNTS310 kbWinNTAdvSerSearch kbWinNTAdvServ310 kbWinNTS310search kbWinNT310Search kbWinNTW310Search
Version           : :3.1

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