Samba-related info on disconnected NT networkshares

Michel michel at
Fri Jul 9 08:54:52 GMT 1999

The issue of disconnected networkshares (shares offered on an NT server) has 
appeared on this mailinglist a few times. It is not a samba issue, but
it seems many here might benefit from the information given below anyways, 
as I've never seen a solution to the problem come by.

Problem: Whenever there has not been any activity (file/network IO) to
or from a networkshare that is offered by an NT server, the drive connection
gets de-activated (disconnected). This can be verfified by issueing the 
"net use" command in a dos window on the win9X client. The share's status
will be marked "Disconnected" rather than "OK". This status may (or will)
result in application errors of applications run from the share (specifically
concerning DLL's residing on that share).
Shares offered by a Samba-server do not appear to have this problem.
Since such file IO is virtually invisible to the user (and netadmin) it is
sometimes difficult to reproduce this problem - it may appear that the problem
does not occur for hours. Keep in mind that if the problem *can* occur,
at some point, it will.

Cause: The cause is a default network setting in NT's registry, disconnecting
(aka "Ghosted Drives") shares after 30 mins of inactivity.

Documentation on this: Virtually nothing; the same problem, its causes and
the solution with RAS connections is desribed extendedly in Microsoft's
knowledgebase. These remedies do not apply for the LAN connections and will
not solve the problem.

Eventually, I received the following article on this matter from Microsoft:

==================== START QUOTE =====================================

ID: Q138365    CREATED: 18-OCT-1995   MODIFIED: 16-MAR-1999
3.5 3.51 4.0
PUBLIC | kbnetwork ntras ntdomain ntconfig NTSrvWkst

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

 - Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0 
 - Microsoft Windows NT Server versions 3.5, 3.51, 4.0 
- ----------------------------------------------------------------------------
- ---


This article documents the Windows NT local area network (LAN) related
Autodisconnect parameter.

Windows NT uses two different Autodisconnect parameters; one for disconnecting
Remote Access Service (RAS) connections and another for disconnecting LAN
connections. The RAS Autodisconnect parameter is well documented in the Windows
NT Server Remote Access Service manual on page 82, but the LAN version is
undocumented. The only published reference to this Autodisconnect is in the
Windows NT Resource Kit NT Registry Entries help file, in an overview of 
entries for the LanmanServer\Parameters section.


You can find the (
LAN Autodisconnect parameter in the registry under the subtree
HKEY_LOCAL_MACHINE under the subkey:


Purpose: The function is to disconnect idle sessions after a set number of
minutes. The number of minutes can be set at a command prompt using the Net
Config Server command. For example, to set the Autodisconnect value to 30

   Net Config Server /autodisconnect:30

The valid value range is -1 to 65535 minutes at the command line.

To disable Autodisconnect set it to: -1

Setting Autodisconnect to 0 does not turn it off and results in very fast
disconnects, within a few seconds of idle time. (However, the RAS 
parameter is turned off if you set it to a value of 0.)

It is preferable to modify the LAN Autodisconnect directly in the registry.
If you modify it at the command line, Windows NT may turn off its autotuning
functions. For additional information, please see the following article in the
Microsoft Knowledge Base:

   ARTICLE-ID: Q128167
   TITLE : Server Service Configuration and Tuning

The valid value range if you edit the LAN Autodisconnect parameter in the
registry is 0 to 4294967295 (Oxffffffff). If you configure the Autodisconnect
option to -1 at the command prompt, Autodisconnect is set to the upper value in
the registry. This is approximately 8,171 years (not tested), which should be
long enough to be the equivalent of turning Autodisconnect off.

Additional query words: prodnt

====================== END QUOTE ========================

The above is information from Microsoft and they hold the copyright
on the article.

The setting described above indeed (after a search of 9 months) does
solve the problem.



  Michel van der Laan	-	michel at

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