• New Search •
• References •
• Support •

Athena System-Board Redundancy Installation

Article Number: H009
Article Type: HowTo
Modified: March 24, 1999

SUMMARY

A key feature of Athena is system redundancy. By using CPU, Configuration, and Power Supply redundancy, an Athena system becomes more resilient to failure, reducing downtime in the event of failure as a result.

This article will describe how to enable the CPU redundancy feature of Athena, and how to ensure that it is operating properly.

MORE INFORMATION

Athena CPU System Board Redundancy provides a main and stand-by CPU for an Athena system. In the event of failure of the main CPU, the stand-by will immediately become the main allowing the system to continue operation without impact. Two CPUs which are capable of becoming the main CPU are called master system boards.

The two main sub-assemblies on the master system board, which differentiate it from other CPU boards, are the configuration plug-in and the SBUS adapter. While all boards in a multi-board Athena node must contain an SBUS adapter, the main board, board 1, differs in that its SBUS is operated as a "master". All others operate in "slave" mode. With System board redundancy, the SBUS on board 2 can assume the duties of the master SBUS.

Similarly, the configuration plug-in holds the configuration information for the chassis and is made redundant by the addition of a configuration plug-in on board 2.

The System board redundancy feature will allow the system to function should either board 1 or 2 fail. When the failed board is replaced all configuration data including any changes is copied back to the Configuration Plug-in of the replaced board.

System Software Required

The following binaries or higher versions are required for Athena "CPU Redundancy".

• sbus101a.bin
• os101b.bin
• tm100h.bin
• nmp101c.bin
• pl101d.bin
• gp101b.bin
• fl101a.bin
• boot101.bin
• ap101.bin
• lb101a.bin

Please note that the versions listed above are not the latest versions, but rather are the minimum versions required. For the latest versions, please refer to Develcon's web site.

System Hardware Required

The following hardware is required:

• A configuration plug-in (NVRAM) must be installed on the CPU located in slot 2. The configuration plug-in has to be the same size as the configuration plug-in installed on the CPU in slot 1.

Verify the Utility Card is adequate

Remove the Utility card from the chassis and check that the module has a 4-position DIP switch mounted near the center of the board. If it does not have the DIP switch the utility card will support redundancy but you will not be able to log into the NMP on board 2 if board 1 fails.

• DIP Switch Settings: Postion 1 to "ON" and 2 to "OFF". Position 3 and 4 are for Power Supply setup and should not be adjusted.

Redundancy Procedure

Now that you have determined if your systems hardware and software can support redundancy, there are a few steps required to enable the feature. Follow the steps listed below to enable this valuable feature.

• Obtain the Signature Manager DSM (Diagnostic Software Manager) from the Develcon Web Site (refer to the REFERENCES section for a URL to the Athena software repository). This software will repair any misconfiguration of the electronic signatures of the Athena CPUs. The signatures must be correct to properly commission the chassis for "CPU Redundancy".
• Enter the following command string from the "Root Command Menu" to run the Signature Manager, di ht si nv
• The following screen will be presented:

                           NVRAM Signature
Item  Identifier  Revision  Manufacture Date  Serial #  # Chips

 1    4Mb           65      1970-01-01        B076       8
 2    4Mb           65      1983-08-10        B093       8




All operational boards reported.
Node1>/Diag/Hwtest/Signatures==========================

• Ensure that all software binaries running on node are the same or higher version presented in the list provided earlier. To view the binaries being used enter the following command string from the "Root Command Menu", co sw bo sh
• To add "CPU Redundancy" the following binaries must be assigned to the CPU in slot 2, TERM (Terminal) and NMP (Network Management Package).
• To assign the above mentioned binaries to the CPU in slot 2 enter the following command string, ar nmp assigns NMP to board 2.
  
  Note, both TERM and NMP must be assigned to CPU in slot 2 to properly enable "CPU Redundancy".
  
  
• To enable "CPU Redundancy" reboot CPU in slot 2 by entering the following command from the "Root Command Menu", ct re 2 now. The following system prompt will be presented,

  This action may terminate user sessions, proceed (y/n)?.

  Enter "y" for yes. The CPU in the second slot will reset.
• Once CPU reboot is completed, the word "Redundant" will appear on the right hand side of the divide line of the Athena screen advising the user that "CPU Redundancy" is enabled. This "Redundant" word will disappear when the CPU in slot 1 or 2 is removed indicating that either CPU in slot 1 or 2 has failed. See example below showing where the "Redundant" word appears on Athena screen:

                         Root Command Menu
ALarms+        COnfig+        ConTrol+       DIag+      FIles+
STats+         HElp           MEnu           EXit




                        Welcome to Athena
                        Region 1    Node 1
                        1999-03-22  14:37:52
                        Serial #  E089


Node1>============================= Alarm == Redundant =====

• The NMP and TERM binaries should be active on the CPU in slot 2. To view, enter the following command string from the "Root Command Menu", co sw tr sh 2. The following screen will be displayed:

BD#   DES.    BINARY.FILE    CONFIG.FILE    STATUS

2     OS      os102b.bin     osconf01.cfg   Active
2     NMP     nmp110g.bin    nmp.cfg        Active/Redundant
2     PL      pl102d.bin     pl01.cfg       Active
2     GPL     gp101k.bin     gpl01.cfg      Active/Redundant
2     TERM    tm100l.bin     terminal.cfg   Active/Redundant
2     SBUS    sbus101f.bin                  Active
2     FRR     frr103.bin     frr01a.cfg     Active
2     XF      xf102c.bin     xf01.cfg       Active




Node1>/Config/Software/Board===== Alarm == Redundant =====

Test Redundancy

It is now prudent to test the system to ensure that the configuration and hardware have been prepared properly. To do so, follow the instructions provided below.

• Simulate a failed board by removing the CPU in slot 1.
  
  Caution, halt all trunks on this CPU before removing it.
  
  
• Established calls between ports not associated with the failed board should continue without interruption when CPU board 1 or board 2 is removed and re-installed.
• New calls placed to ports not associated with the failed board/s should be routed and established properly.
• Configuration / routing changes made while a board is failed should be copied to the replaced board and continue to be in effect.
• Insert CPU 1 back into the chassis. CPU 1 will become the master.
• If garbage is received on the Terminal port when the CPU in slot 1 is removed, then the TERM interface speed configuration being used on CPU 2 is different from the configuration being used on CPU 1. The factory default setting for the terminal interface speed is 19.2Kbps. To correct this problem, you will have to match the interface speed on both Terminal configurations. The terminal interface speed is adjusted at the Terminal prompt. Enter co at the Terminal prompt. The following Menu will be displayed:

Terminal Parameter Configuration (Version TM100K)

BAud_rate        CAll_timer       CallinG_address  ECho
NullPad          PacketSize       PRompt           THroughput
WindowSize       SHow             SAve             HElp
MEnu             QUit

Terminal:

• To change the baud rate enter, ba 19200. The speeds the Terminal interface supports are, 1200, 2400, 4800, 9600, 19200, 57600.
• Once the speed has been changed, the speed of the Terminal connector to this interface will have to be adjusted.
• Before exiting out of this menu enter sa. This command saves the Terminal interface configuration.

REFERENCES

To obtain the Athena Signature Manager DSM (sig.dsm), proceed to Develcon's FTP Server.

Refer to the system documentation for additional details regarding CPU redundancy. §

Copyright © 1999 Develcon Electronics Ltd.  All Rights Reserved.