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Problem Resolution

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Problems that can occur while installing, configuring, and running an SNA link — and how to deal with them — are described here. Guidelines for submitting a change request (CR) are also given.

Common Problems


Some problems are common to many situations — invalid software installation, version incompatibilities, insufficient MPE resources, corrupt configuration files, and file system errors. In most cases, you can resolve these problems yourself; the resolutions to these problems are described here. However, in some cases you should submit an CR. To enable Hewlett-Packard to solve your problem in an efficient manner, you should follow certain guidelines when submitting an CR; these guidelines are listed later in this chapter.

Invalid Software Installation

A software installation might be invalid. Run NMMAINT to get a listing of all software modules and their version IDs. Check that all required modules are present, and that the first five characters of the version IDs (the v.uu.ff fields) of these modules are the same within each subsystem. Finally, check the version IDs with the SYSTEM STATUS BULLETIN or other HP source to be sure the versions of software you have are supported by the version of MPE you have. If a problem is found with any of these checks, you have an incorrect software version installed. Locate a known valid version of the suspect software (perhaps from one of your system backup tapes) and install it.

Version Incompatibilities

Version incompatibilities between NMS software and other subsystem software are possible. Run NMMAINT to get a listing of version IDs for NMS and for all of the NMS-dependent subsystems. Locate the overall version IDs for NMS and for each subsystem. Compare the first five characters of these version IDs (the v.uu.ff fields) with those listed as compatible with each other in the SYSTEM STATUS BULLETIN or other HP source. If a discrepancy is found, locate a known set of compatible software (perhaps from one of your system backup tapes) and install it.

Insufficient MPE Resources

The system might have insufficient MPE resources such as configured table sizes. Use HP Glance/XL (HP 50734A) to check MPE table utilization. Reconfigure MPE to fix any problems found and restart the system.

Corrupt Configuration File

The configuration file might be corrupt. Validate the configuration file to check for possible corruption. If the error persists, use NMMGR to manually check the configuration file (if possible). If bad records seem to be localized to a particular item, delete that item and reconfigure it. If necessary, RESTORE a backup copy of the file.

File System Errors

A file system error might have occurred while trying to access the configuration file. Try to access the configuration file, under the same userid, using NMMGR. Use the NMMGR error screen to find out what the underlying FSERR is. Correct the problem and retry.

Configuration Problems


Configuration problems can occur on both the HP e3000 and the host.

HP e3000 Configuration Problems

Listed below are some configuration problems that can occur on the HP e3000.
  • PSI problems.

    When you run the PUs concurrently, each PSI requires a unique PU and each PU requires a unique PSI.

    Also, if you are using an SDLC link, ensure that you correctly configured the Physical Path field of the "SNA Node Configuration: SDLC Link Data" screen (see Chapter 2 "SNA Node and Link Configuration" of this manual).

  • Configuration file misnamed.

    Remember, when configuring a node, the configuration file can be named anything you prefer. However, when you start the SNA link, it looks for a configuration file named NMCONFIG.PUB.SYS.

Host Configuration Problems

Listed below are some configuration problems that can occur on the host.
  • Incorrect device specified.

    Too many or the wrong type of device might have been configured for a particular line.

  • Incorrect macro definition.

    Macro operands might have been incorrectly placed within the hierarchical structure. Although the operands for lower-level macros can be defined in a higher-level macro, this structure must be followed: GROUP, LINE, SERVICE, PU, and LU.

    A macro could be missing a required operand or an invalid operand might have been specified for a particular macro.

Installation Problems


Some common problems that might occur during installation, or as a result of improper or unsuccessful installation, are described below.
  1. Inactive VTAM node.

    This is probably the most common problem that occurs on the host. Ensure that the proper activation commands have been issued. Setting the ISTATUS operand of the LU macro to ACTIVE will help, especially if it is moved up to either the GROUP or LINE macro. (The ACTIVE setting sifts down to all lower-level macros.) This problem most frequently occurs in a switched line configuration when the major node containing the VBUILD macro was never activated. In this case, an inactive macro causes the host to fail to find a match for the remote's Exchange Station Identification (XID) number. The only way you will be aware that this XID problem has happened is a message at the host operator's console. To avoid these problems remember this rule: When in doubt, activate.

  2. Switched lines.

    Be sure the VBUILD macros are in a separate member in the VTAM parameter library (SYS1.VTAMLST).

  3. Hardware problems.

    Ensure that all hardware is installed properly. Many problems are related to such things as incompatible modems, bad phone lines and cables, etc.

    Ensure that the host is up, the line is active (being polled), and the host telecommunications subsystem (for example, VTAM) is active. You might need to use a line monitor, such as an HP 4953, to check whether the line is being polled and to determine the addresses being polled. You also can use one of the other HP 495x Protocol Analyzers in addition to the standard HP 4953.

Submitting an CR


Listed below are some guidelines for submitting a change request (CR). Some of the guidelines refer to Node Management Services (NMS) programs (NMDUMP, NMMAINT, and NMMGR). Using NMDUMP and NMMAINT for an SNA link is explained earlier in this chapter. Using NMMGR for an SNA link is explained in Chapter 2 "SNA Node and Link Configuration" of this manual. For more NMS information, see Using the Node Management Services Utilities.

Common Information

For any CR, include this common information, where applicable:
  • A characterization of the problem. Describe the events leading up to and including the problem. Try to describe the source of the problem. Describe the symptoms of the problem.

    Your characterization should include MPE commands, communication subsystem commands, job streams, result codes and messages, and data that can reproduce the problem.

    List the context and environment in which the message occurred. Prepare copies of the HP e3000 system console information.

    Give a brief history of your site, including when the SNA link product was installed, the circumstances that usually produce problems, other data communications products installed, and any other products you were using when the problem arose.

  • Obtain the version, update, and fix information for all software by running NMMAINT. This allows Hewlett-Packard to determine whether the problem is already known and if the correct software is installed at your site.

  • Record all result messages and numbers that appear at the user terminal and the system console.

  • Run NMDUMP to format the NM log file (NMLGnnnn.PUB.SYS) that was active when the problem occurred. You might need to issue the MPE command SWITCHNMLOG to free the NM log file (see chapter 6 of this manual). Inspect the formatted output and try to locate errors. Prepare the formatted output and a copy of the log file for your Hewlett-Packard support contact to analyze.

  • Prepare a listing of the configuration file and the MPE configuration you are using for your Hewlett-Packard support contact to analyze. Inspect the output and try to locate errors.

  • Try to determine the general area, within the software, where you think the problem exists. If you think the problem is caused by an SNA service, refer to the service's Node Manager's Guide and follow the guidelines there for gathering information for problems.

  • Document your interim, or "workaround," solution. The cause of the problem can sometimes be found by comparing the circumstances in which it occurs with the circumstances in which it does not occur.

  • If a system failure occurs, a full memory dump must be taken.

  • Save copies of all active or in-use trace files for analysis by your Hewlett-Packard support contact.

  • Save copies of all active or in-use log files for analysis by your Hewlett-Packard support contact.

  • Always obtain a copy of the generation of the host system you are using for ACF/VTAM and ACF/NCP. For the host system to be compatible with the SNA link, Hewlett-Packard sets certain operands and parameters to required values (see Chapter 2 "SNA Node and Link Configuration" of this manual). Note any differences between the actual system generation and your expectations. Keep this information for your Hewlett-Packard support contact. This is very important.

  • Give a copy of NMCONFIG.PUB.SYS to your Hewlett-Packard support contact.

SNA Transport Information

For problems that involve SNA Transport, include the following additional information where applicable:
  • Always issue the MPE command

    SNACONTROL STATUS;NODE=NodeName

    to identify the state of the PU and the LUs in the problem node. Inspect the output to try to locate an identification of the problem. Keep a copy of the output from this command for your Hewlett-Packard support contact.

The SNACONTROL commands are described in Chapter 6 "MPE Commands" of this manual.

SDLC Communications Link Information

For problems that involve the SDLC communications link, include this additional information where applicable:
  • If a fatal SDLC link error has occurred, a message in this format is displayed on the operator's console:


  Linkname       = LinkName       Event Type     = EventType
  Log Class      = LogClass       Location       = Location
  Sublocation    = Sublocation    Error Code     = ErrorCode
  State          = State          Cause Status   = CauseStatus
  Error Actions  = ErrorActions

  • Be sure to include this error message in the CR exactly as it appears on the operator's console.

  • If a PSI failure has taken place, give the PSI dump file NETDMPnn.PUB.SYS (where nn is a number from 00 through 99) to your Hewlett-Packard support contact for analysis.

    If the problem is easily reproducible, and link-level tracing was inactive when the problem took place, turn on link-level tracing with the MPE command SNACONTROL START or SNACONTROL TRACEON (see Chapter 6 "MPE Commands" of this manual). When the problem has been reproduced, turn off the tracing and give the PSI dump file and this trace file to your Hewlett-Packard support contact for analysis.


    NOTE: It is important to give a copy of the PSI dump that took place while link-level tracing was enabled to your Hewlett-Packard support contact for analysis.
  • If a PSI failure has not taken place, turn on link-level tracing with the MPE command SNACONTROL START or SNACONTROL TRACEON (see Chapter 6 "MPE Commands" of this manual). This allows your Hewlett-Packard support contact to study the line activity.

  • If link trace logging is enabled, use the SWITCHLOG command to close the current system log file (LOGnnnn.PUB.SYS, where nnnn is a number from 0000 through 9999) and open a new one. Then, give a copy of the system log file you just closed to your Hewlett-Packard support contact to analyze.

  • If link trace logging is not enabled, enable it through NMMGR so that the information will be available if the problem can be reproduced.

X.25 Communications Link Information

For problems that involve the X.25 communications link, include this additional information where applicable:
  • If a fatal X.25 link error has occurred, messages in these formats might be logged:

    
      Link connect failure on node NodeName
      Subsystem=SubsysID, Error Code=ErrorCode
    
      Link failure, shutting down the node NodeName
      subsystem=SubsysID, procedure=ProcNum, error num=ErrorNum
      SOCKERR nnn
    
      Link failure, shutting down the node NodeName
      subsystem=SubsysID, procedure=ProcNum, error num=ErrorNum
    
    
    Be sure to include these error messages in the CR exactly as they appear on the operator's console.




Using NMMAINT for the SNA Links


Chapter 6 MPE Commands