Recovering from a Failed Server


Recovering from a Failed Server



When replacing a failed server in a high-availability configuration, you might not need to replace the ServeRAID II adapter.
However, if you replace your ServeRAID II adapter, you must reconfigure the adapter after you have installed your new server.

  -Important- The following procedure requires specific configuration settings for the ServeRAID II adapter. If the server and adapter that are being replaced are functional, you can obtain these settings from the adapter.
However, if the adapter or the server is not functional, you will need a record of these settings, such as one that was created when the adapter was previously configured.
If you are replacing your ServeRAID II adapter with your server, you must have correct configuration information to complete this procedure.


Use the following procedure to recover from a failed server:

  1.  Remove the failed server from your high-availability configuration.
  2.  Remove all hard disk drives from the disk drive array in the failed server.

     As you remove your hard disk drives, be sure to note the bay in which each drive was installed. If you  are replacing your failed server with an identical server you can reinstall the drives in an identical  configuration and get your server up and running quickly.

  3.  If the ServeRAID II adapter is functional, remove it from the failed server.
     As you remove the adapter from the failed server, be sure to:

     If you are replacing your failed server with an identical server, you can reinstall the ServeRAID II  adapter in an identical configuration and get your server up and running quickly.

  4.  Install the hard disk drives in the new server.

     For information on how to install a hard disk drive, see the documentation that is included with your  server. If you are replacing the failed server with an identical server, install each hard disk drive in the  same bay as the one it was removed from in the failed server.

  5.  Install the new ServeRAID II adapter.

     For instructions on how to install the ServeRAID II adapter, see the 'IBM ServeRAID II Installation and User's Guide'.  If you are installing a ServeRAID II adapter that was previously installed in the failed server, install the  adapter in the same PCI slot as it was installed in the failed server.

      -Important- Do not reconnect the SCSI channel cables to the adapter at this time.

  6.  Configure the ServeRAID II adapter in the new server.

    Note: If you have installed the adapter in a server that is identical to the failed server and have  installed it in the same PCI slot where it was installed in the failed system, you might not need  to configure the adapter.

     You will need the following information to configure your new ServeRAID II adapter:

     If the ServeRAID II adapter and server that you are replacing are functional, you can obtain this  information by starting the server with the IBM ServeRAID Configuration Diskette  and selecting the Display/Change Adapter Params item from the Advanced Functions menu.

     If the ServeRAID II adapter or server is not functional , you will need to refer to the record of the  settings that you made when the adapter was previously configured. If you do not have a record of  the configuration information, the following hints might help you to assign the proper values.

  7.  Start the system from the IBM ServeRAID Configuration Diskette  Version 2.40, or higher.
  8.  Initialize the adapter configuration.

     To initialize the adapter:

    1.  Select Advanced Functions from the Main Menu.
    2.  Select Init/View/Synchronize Config.
    3.  Select Initialize Config.

  9.  Ensure that the adapter is at the latest BIOS/Firmware level.

     The BIOS/Firmware level of the adapter is displayed after system POST when the adapter BIOS/Firmware loads.
     The latest BIOS/Firmware levels are available from the IBM Web site at

    http://www.pc.ibm.com/support

     When you have connected to this Internet address, search for RAID BIOS. Download and read the  text file to determine the latest levels available. If your adapter BIOS/Firmware is downlevel, download  and apply the BIOS/Firmware update.

  10.  Update the configuration parameters.

     To update the configuration parameters:

    1.  Start the system from the IBM ServeRAID Configuration Diskette  Version 2.40, or higher.
    2.  Select Advanced Functions from the Main Menu.
    3.  Select Display/Change Adapter Params.
    4.  Using the settings that were assigned to the ServeRAID II adapter you are replacing, select and configure each of the following parameters:

      •  SCSI Bus Initiator_IDs
      •  Adapter Host_ID
      •  Cluster Partner Host_ID

    5.  Select Change RAID Parameters from the Advanced Functions menu and enable unattended mode.

  11.  Shut down the system and reconnect the SCSI channel cables to the adapter. Be sure to connect the  cables to the correct SCSI channels as noted in (above) step 3.

      -Important- If the ServeRAID II adapter being replaced is not the adapter that attaches to the server startup  disk array or other nonshared disk arrays, you do not need to perform any of the following steps.
     The system can now be restarted normally.

  12.  If the adapter that was replaced attaches to the operating system startup disk array for the system or if  other nonshared disk arrays are attached to this adapter, start the system using the IBM ServeRAID Configuration Diskette  Version 2.40, or higher, and then:

    1.  Select Advanced Functions from the Main Menu.
    2.  Select Merge Group Management
    3.  Restore the adapter disk array configuration.

      •  To restore nonshared disk array configurations:

          1) Select Merge Group Management from the Advanced Functions menu; then, press Enter.
          2) Select Merge/Unmerge Logical Drive, and then press Enter.
          3) Select Merge Own Nonshared Logical Drive.
          4) Type in the Group ID field the Merge Group ID for the array 2xx 

          where xx is the shared SCSI Bus Initiator_ID, and then press Enter.
          The Merge Group ID value is typically 206 or 207.
          A message appears at the bottom of the screen saying

          Merging own shared logical drive(s). Please wait...

          5) When the process completes, a message appears saying

          Merge/Unmerge operation completed successfully.
          Press any key to continue.

          6) Press Esc to return to the previous menu. Continue pressing Esc to return to the Main Menu.
          If the adapter you are replacing is the boot adapter, the system should now be
          able to start up the operating system properly.

      •  To restore shared disk array configurations:

        Note: Usually all shared arrays will have failed over and will not need to be merged.

          1) Select Merge Group Management from the Advanced Functions menu; then, press Enter.

         A screen similar to the following appears.

         
          2) Select Merge/Unmerge Logical Drive and then press Enter.
         
          3) Select Merge Own Shared Logical Drive for each shared array (Merge Group IDs in the
          range 1-8) that has not failed over to the cluster partner system (for example, RAID level-5
          arrays in critical or degraded state) to restore the configuration of these shared arrays.

          4) Press Esc to return to the previous menu. Continue pressing Esc to return to the Main Menu.

          Repeat this process for each shared array (Merge Group IDs in the range 1-8) that has
          not failed over to the cluster partner system (for example, RAID level-5 arrays in
          critical/degraded state) to restore the configuration of these shared arrays.

          -Important- The IBM ServeRAID Configuration Diskette  must not be used to perform failover and  failback to merge or unmerge drives belonging to the other server.
         Failover and failback to merge or unmerge drives belonging to the other server is normally handled  by the operating system software and cluster support software.

  13.  Restart your server.

     When all array configurations have been restored, the server can be restarted normally.


Back to  Jump to TOP-of-PAGE

Please see the LEGAL  -  Trademark notice.
Feel free - send a Email-NOTE  for any BUG on this page found - Thank you.