Advanced Server Troubleshooting Tools

Advanced Server provides a variety of tools that can be used as troubleshooting aids. These tools can be arranged into the following three categories:

Tools used for assessing the status of the server.
Tools used for automatic notification of the status of the server.
Tools used for debugging specific server problems.

The following sections summarize the tools found in each category and briefly describe the use of each in a troubleshooting context.

Tools for Assessing the Status of the Server

Advanced Server includes multiple tools that can be used to assess the operational status of the server at any given time. As a server administrator, frequent assessment of server status will improve your ability to notice a problem or trend quickly.

Periodic review of server status will provide a fairly stable basis for understanding how a normal problem-free server appears. Over time, information that deviates from the norm will be an indication that something has changed and warrants your attention.

Tools for assessing the status of the server include the following.

Event Viewer

A number of events related to the daily operation of the server can be tracked using Event Viewer . These events are maintained in one of three event logs: system, security, and application. Administrators should develop and implement an event logging policy and include a review of event logs as a regular part of troubleshooting activities.

Administrators will find it particularly useful to characterize the typical use of the server by manipulating event log data using a spreadsheet or word processing program. This approach can be used to generate a standard operating profile of the server and can be used to predict trends in server usage.

For information about Event Viewer, see Advanced Server Concepts and Planning.




	NOTE: Event logs also can be viewed using the elfread command. For more information, type man elfread at the Advanced Server command prompt.

Server Statistics

Advanced Server maintains detailed statistics about its current usage as well as cumulative usage over a particular period of time. It is always helpful to review these statistics on a regular basis as well as when a server problem is encountered.

Current Statistics

To view data about current server use, use Server Manager. This provides details about current client-server sessions and the resources being used by those sessions.

Cumulative Statistics

To view cumulative server usage data, use the net statistics command at the Advanced Server command prompt. This command provides cumulative totals for a variety of server activities. Administrators who review the server statistics provided by using this command on a regular basis will find it easier to recognize and address changes in server operation.

The following statistics are maintained for the Advanced Server:

Statistic	Description
Statistics since	Tells when this set of statistics began (either at the last server startup or the last time the statistics were cleared).
Sessions accepted	Tells how many times users connected to the server.
Sessions timed-out	Tells how many user sessions were closed because of inactivity.
Sessions errored-out	Tells how many user sessions ended because of error.
Kilobytes sent	Tells how many KBytes of data the server transmitted.
Kilobytes received	Tells how many KBytes of data the server received.
Mean response time (msec)	Tells the average response time for processing remote server requests. This always will be 0 for UNIX system servers.
System errors	This does not apply to UNIX system servers.
Permission violations	Tells when a user attempts to access resources without the required permissions.
Password violations	The number of incorrect passwords that were tried.
Files accessed	The number of files that were used.
Comm devices accessed	Not supported on Advanced Server.
Print jobs spooled	The number of print jobs were spooled to printer queues on the server.
Times buffers exhausted	The number of shortages of big and request buffers. Always set to 0 for UNIX system servers.

Session Information

Administrators can display and control sessions between clients and the server. This information can be used to gauge the workload on a particular server.

To display session information from a Windows NT Workstation computer or a Windows client computer using Server Manager.

Start Server Manager.
Select the Advanced Server about which you want to view session information.
Click on the USERS button.

You also can display session information using the net session command at the Advanced Server command prompt.




	NOTE: You may see sessions displayed that do not show user names. The sessions are a result of administrative activity and should not be deleted.

Closing Sessions

An administrator can disconnect a user from the server at any time. Closing a user session does not prevent the user from reconnecting.

To disconnect a user session from a Windows NT computer or from a Windows client computer using Server Manager

Start Server Manager.
Select the Advanced Server about which you want to view session information.
Click on the USERS button.
Highlight the user and select the Disconnect button.

You also can disconnect a user session by using the net session command at the Advanced Server command prompt.

Open Resources

When a user uses a shared file, the file is open. Sometimes a file will be left open, perhaps even with a lock on it, because of an application program error or some other problem. Such files will remain open and unavailable to other users. Administrators can close these files.

To close an open resource from a Windows NT computer or a Windows client computer using Server Manager

Start Server Manager.
Select the Advanced Server about which you want to view data.
Click on the IN USE button.
Highlight the open resource and select the Close Resource button.

You also can close an open resource by using the net file command at the Advanced Server command prompt.

Print Subsystem Event Logging

Advanced Server maintains a separate print log for each printer share and each UNIX system printer it uses. These log files record any message generated because of a printer fault or print job error.

An administrator should check these log files periodically to determine whether any such errors are occurring. The logs can be accessed from a client computer by linking to the PRINTLOG shared resource.

The logs also can be accessed from the server. They are in the following directory: /var/opt/asu/lanman/shares/printlog.

Tools Providing Automatic Status on the Server

Quick response time is critical when dealing with server problems. Being aware of a problem at the time it occurs can decrease greatly the effect that the problem may have on the server user community.

Advanced Server can be configured to notify specified users when a problem occurs. The UNIX system also can be configured to generate and notify the system administrator when problems occur. The following sections discuss these features.

Alerter Service

Advanced Server includes an Alerter service which can be used to notify specified users of the occurrence of a particular event. An administrator should use this service in order to make server problems known immediately. Prompt action to resolve server problems often can minimize their effect. The following examples illustrate situations that could generate alerts:

The number of server errors exceeds a threshold set in the Advanced Server Registry.
The number of bad access attempts exceeds a threshold set in the Advanced Server Registry.
The number of bad password attempts exceeds a threshold set in the Advanced Server Registry.
Errors were encountered during start of the Net Logon service.
A printer is malfunctioning.
A print request has been deleted or completed.

UNIX System and Advanced Server Features

One of the benefits of Advanced Server is the availability of the inherent scripting features provided by the UNIX operating system. Combining these features with the data gathering tools provided by Advanced Server, an administrator can create a powerful tool that can be used to assess the health of Advanced Server at any given time.

For example, using the UNIX system job scheduling feature (CRON), various data gathering tools provided by Advanced Server, and some of the standard UNIX system commands for checking file system integrity and free space, administrators can write scripts that perform various system and server checks and then send the results to UNIX system administrators at regular intervals.

Tools for Debugging Server Problems

Advanced Server includes UNIX system commands that can be used to troubleshoot server problems. These commands are executed at the Advanced Server command prompt. This section summarizes these commands and describes the roles they can play in troubleshooting a server.

For more information about each command, type man command at the Advanced Server command prompt.

lmshell

The lmshell command is useful for emulating an MS-DOS client session when you do not have access to an actual MS-DOS client. This command is especially useful when troubleshooting a connectivity problem between a client and server. Using the lmshell command, you can mimic a client logon and resource linking by executing the net logon and net use commands in lmshell at the Advanced Server command prompt.

lmstat

The lmstat command interrogates the server's shared memory image to gather a variety of data about the current state of the server. This command is especially useful when you want to determine which server process a client session is on.

Advanced Server is composed of a set of cooperative processes. When the server is running, enter the following command:

ps -ef | grep lmx

Executing this command generates a display similar to the following:

root   	17726  	1		       0	   12:03:36   	0:00	lmx.alerter
root   	17713  	1746	1	   0   	12:03:32   	0:00	lmx.srv -s 1
root   	17722  	1787	4   	0	   12:03:35   	0:00	lmx.srv -s 2
root   	17726  	1		       0	   12:03:36   	0:01	lmx.dmn
root   	17728  	1       		0   	12:03:36   	0:01	lmx.browser
root   		17744  	1		       0   	12:03:28   	0:00	lmx.ctrl

In this example, there are two lmx.srv server processes (17713 and 17722). The server may have nine clients with current sessions.

How does the administrator know to which lmx.srv process a client is connected? Executing the lmstat -c command at the server prompt usually provides the answer. The system displays output similar to the following:

Clients:
BANANA.SERVE~X (nwnum=0, vcnum=0) on 17713
ORANGE (nwnum=0, vcnum=0) on 17713
PEAR (nwnum=0, vcnum=0) on 17722

Notice that each client name has an associated process ID number. This is the process ID of the lmx.srv process that currently is serving that client. The vcnum value specifies whether this is the client computer's first VC or an additional one.

regconfig

The regconfig command is used to query or change Advanced Server Registry key information. You can use this command to change any value in the registry. (You also can use the Windows NT Registry Editor and the AS/ U Administrator to change key values.)

The regconfig command also can be used to reinitialize the Advanced Server Registry with system defaults.

For more information about the registry, see Appendix A, "Advanced Server Registry."

regcheck

The regcheck command is used to check and repair the Advanced Server Registry file. This command checks only the internal structure of the Advanced Server Registry file; it does not check the validity of any data that may be stored in it.

If the internal structure of the registry file is found to be invalid, use the regcheck command to make the necessary repairs.

samcheck

The samcheck command is used to check, dump, and fix the SAM database. You can use this command to determine whether the user accounts database has been corrupted and optionally, to fix it.

The samcheck command also can be used to output the contents of the user accounts database to stdout in human-readable format.

srvconfig

The srvconfig command is used to display the current default settings of all the server parameters in the lanman.ini file. (It also is a good way to check the location and spelling of any parameter you wish to modify.)

The lanman.ini file contains several parameters that you can modify to change. Default settings are used for most of these parameters. However, a certain number of them can be changed, overriding the default values set at server installation.

To display the default settings of the lanman.ini file, use the following command:

srvconfig -p | more

This command generates a listing of all of the parameters in the lanman.ini file and their default settings.

For more information about the lanman.ini file, see the Appendix B, "Lanman.ini File."

acladm

The acladm command is used to check and repair problems found in the access control list.

Be sure to examine the options that are available with this command before executing it. Type man acladm at the Advanced Server command prompt.