User-configurable server tuning in versions of LAN Manager before 2.1
required system administrators to have considerable knowledge of the
structure of LANMAN.INI (in order to edit the file), the OS/2 operating
system (to optimize performance) and resource requirements (to ensure
effective operation). If these three areas were not sufficiently
understood, the "tuned" LAN Manager server would operate poorly and
provide users with inadequate resources.
In versions 2.1 and later, autotuning does much of the server tuning for
you, but there are still some issues that you need to be aware of.
This article contains part 2 of a discussion of these issues. For part 1,
query on the following words:
If one of these parameters is exceeded during server operation, an
error message is entered in the server error log. To correct the
problem, restart the server. The new "server best" parameters
will be implemented.
Example: Maxusers exceeded on the server, workstation receives
MS-DOS error 71 or OS/2 error SYS0071: The network request was not
accepted.
Solution: If the server is not an unlimited version, installation
of an addpak may be necessary to increase the number of users that
can access the server simultaneously. Run NET CONFIG SERVER to
determine the server level. However, if the server is an unlimited
server, restart it when doing so will not interrupt active users.
A new autotuned value will be implemented.
To restart the server, type the following commands:
net stop server
net start server
Refer to the "Sessions" section below for further information.
Server shut down improperly.
All of the server autotuning functions depend on statistics that
are saved and stored in SERVER.CFG. During the first 48 hours
following server startup, the SERVER.CFG file is not saved, and if the
the server is improperly shut down during this period these statistics
are lost. If the server halts during this period without being shut
down, the server autotuning parameters are lost. However, the command
NET STOP SERVER saves the parameters to SERVER.CFG and once the server
has been in operation for more than 48 hours, the SERVER.CFG file is
saved automatically.
To shut down the server properly:
Type: net stop server (you must be logged in with admin privileges)
Type: net logoff
Type: net stop workstation
Type: cache /lazy:off
From the OS/2 Desktop menu, choose Shutdown.
Sessions
Problem: Server session limit exceeded.
Server error log: Net5317: The local session table is full. The NCB
request was refused. The NCB is the Data.
Workstations display: MS-DOS error 51, remote computer is not
listening. OS/2 SYS0051, The remote computer is not available.
Solution:
LANMAN.INI
The Maxconnections resource is dynamically autotuned so that users
can use as many resources on a server as they require. Maxusers, a
LANMAN.INI parameter, is the maximum number of clients who have
connected to one or more resources on a server. A client using
server resources has one session with that server. One session may
contain one or more connections to resources on the same server.
Maxusers is a statically autotuned LANMAN.INI resource so that upon
system shutdown and restart, the best server value is used. However,
autodisconnect must be set manually to a reasonably low value such
as 10, so that sessions not in use for more than 10 minutes can be
allocated for use by other active users.
PROTOCOL.INI
Server protocol resources are specified in PROTOCOL.INI. They
are not autotuned parameters, so they must be set manually by
editing CONFIG.SYS. The total number of server sessions allocated
should be equal to the current value of maxusers + 1. Use READCFG
to determine the current value of this parameter. If the parameter
has been manually overridden, use the value listed in LANMAN.INI.
Increase NCBS and Names as well. By default, these values are hidden
and not listed in PROTOCOL.INI. You can increase them by explicitly
entering values.
Note: TcpConnections must be set to the maximum number of combined
TCP/IP socket sessions and server sessions, NumSessions. NumSessions
must be set to the maximum number of RFCNetbios sessions, the number
of sessions that TCP/IP LAN Manager workstations will establish with
the server, maxusers + 1.
Cache too large, slow operation
For most LAN Manager server installations, cache autotuning is
performed statically and provides optimal server response for
HPFS386 volumes. However, if the server cannot allocate available
OS/2 memory for server services, value-added services, and
applications, the server performs slowly. Value-added services
include Microsoft LAN Manager connectivity products such as LMFSA,
RAS, and Comm Server, and various third-party services including
3Com services for the 3Server. The \SWAPPATH\SWAPPER.DAT file may
grow beyond the default (512K). Swappath is specified in CONFIG.SYS
and is \OS2\SYSTEM by default. Use the DIR command to determine
whether this file has been updated. Under normal operation, this
file should not be updated by OS/2 after server startup. If it is
being used, swapping to disk is taking place and the server may
exhibit thrashing and slow response.
Solution: Increase the server RAM. OS/2 1.31 can use up to 16 MB of
RAM. Manually override the Cache:auto setting in CONFIG.SYS by
specifying an appropriate setting (for example, 256, 1024, 2048, or
4096). Restricting the size of reserved cache, makes system RAM
available to OS/2. Change this parameter using LAN Manager Setup.
Select the Configuration, Server Settings, and File System options,
and fill in the HPFS386 Cache value as prompted.
Net3053: LAN Manager doesn't recognize "invalidparameter" as a
valid option
When editing LANMAN.INI, enter the parameter correctly and do not
add a dynamic resource parameter. Although these parameters are
included in LANMAN.INI in versions earlier than LAN Manager 2.1,
they have been made obsolete.
This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.