LAN Manager 2.1 Server Autotuning (Part 2)

ID: Q80078

The information in this article applies to:

Microsoft LAN Manager, versions 2.1, 2.1a, 2.2

SUMMARY

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:

autotuning and part 1

MORE INFORMATION

Common Errors or "Gotchas"

Server static autotuned parameter(s) exceeded.

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:
1. Type: net stop server (you must be logged in with admin privileges)
2. Type: net logoff
3. Type: net stop workstation
4. Type: cache /lazy:off
5. 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:
1. 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.
2. 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.
  
  Sample NetBEUI PROTOCOL.INI:
```
         [Netbeui_Xif]
         DriverName = Netbeui$
         Bindings = "adaptername"
         Names  = 17
         NCBS = 85
         Sessions = 40 
```
  Sample TCP/IP PROTOCOL.INI:
```
         [TCPIP_XIF]
         DriverName = TCPIP$
         Bindings = "adaptername"
         TcpConnections = installation setting (0-254)

         [RFCNetbios]
         DriverName = TCPNB$
         Bindings = "adaptername"
         NumNcbs = installation setting (0-254)
         NumNames = 3 (4-64)
         NumSessions = 3 (0-254) 
```
  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.

Sample CONFIG.SYS Cache Statement:
```
   IFS=C:\LanMan\NetProg\Hpfs386.Ifs /I:c:\lanman /Autocheck:C /Cache:Auto 
```

LANMAN.INI option not recognized

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.

Sample Default LANMAN.INI


;;*****************************************************************;
;**                  Microsoft LAN Manager                      **;
;**            Copyright(c) Microsoft Corp., 1991               **;
;*****************************************************************;

;  LAN Manager initialization file, for server configuration.

[networks]
; This info is read by redir at device init time. It is available to
; applications via NetBiosEnum.
  net1 = netbeui$,0
  net2 = ubdrv$0,0


[workstation]
  computername = Jsbach
  domain = ssbulab
  othdomains = nbu,domain,langroup

  wrkservices = messenger,netpopup
  wrknets = net1,net2

[messenger]

[netshell]
  refresh = 15
  remote =
  username = admin

[version]
  lan_manager = 2.1.RC3

[server]
  alertnames =
  auditing = no
  security = user
  srvservices =
  srvcomment = Darrylw: XNS, Netbeui, LM21 rc3

  srvnets = net1,net2

[alerter]

[netrun]
  runpath =

[replicator]
  logon = user
  password =
  replicate = import
  tryuser = yes

[ups]
  batterytime = 60
  recharge = 100
  signals = 100
  voltlevels = 100
  cmdfile =

[netlogon]

[remoteboot]

[services]
; Correlates name of service to pathname of service program.
; The pathname must be either
;    1. An absolute path (including the drive specification)
; -or-
;    2. A path relative to the LANMAN root

  workstation = services\wksta.exe
  server = services\netsvini.exe
  messenger = services\msrvinit.exe
  netpopup = services\netpopup.exe
  alerter = services\alerter.exe
  netrun = services\runservr.exe
  replicator = services\replicat.exe
  ups = services\ups.exe
  netlogon = services\netlogon.exe
  remoteboot = services\rplservr.exe
  timesource = services\timesrc.exe


CACHE /OPTIONS Output
---------------------

Cache options
Cache Size     6144 KB
Heap Size        65 KB

Drive C:
   Lazy write:              ON   MaxAge:          10000 msec
                                 BufferIdle:       1000 msec


CACHE /STATS Output
-------------------

Cache Statistics

Read Requests:               371577     Disk Reads:          8008
Cache Hit Rate (Reads):          97%    Cache Reads:       363569

Write Requests:              125241     Disk Writes:         7912
Cache Hit Rate (Writes):         93%    Lazy Writes:       117329

Hot Fixes:           0


Viewcfg Ouput
-------------

New server settings:
 maxsearches =  10   maxconnections =  10   maxlocks      =  10
 maxchdevq   =  10   maxopens_mfile =  10   maxopens_sfile=  10
 numbigbuf   =  20   numreqbuf      = 160   maxshares     =  64
 maxusers    =  20

Old server settings:
 maxsearches =  50   maxconnections = 128   maxlocks      =  64
 maxchdevq   =   2   maxopens_mfile =  64   maxopens_sfile=  64
 numbigbuf   =  20   numreqbuf      = 160   maxshares     =  64
 maxusers    =  20

Auxiliary data:
 userlevel   =   1   sizreqbuf      =4356   checksum      =46a8

Additional query words: 2.10 2.1 2.10a 2.1a 2.20 2.2

Keywords :
Version : :2.1,2.1a,2.2
Platform :
Issue type :