Reverting clusters

If you have a high-availability cluster, you must complete additional tasks when you revert from the new version of Informix®. You must revert only the primary database server.

The server automatically removes secondary servers during reversion. After reversion on the primary server is complete, you must recreate all HDR, RS, and SD secondary servers in a high-availability cluster.

Prerequisites:

When you revert clusters, be sure to stop and start the servers in the cluster in the order shown in the following procedure.

To revert high-availability clusters:

  1. Stop the Connection Manager by issuing the oncmsm -k connection_manager_name command.
  2. If you are using a High-availability Data Replication (HDR) secondary server as a backup server in case of contingencies:
    1. Quiesce the primary server by issuing an onmode -sy command to prevent user connections to the server.
    2. Force a checkpoint by issuing an onmode –c command on the primary server.
  3. Stop the servers in the cluster and perform the following tasks in the following order:
    1. If you have remote standalone (RS) servers, stop them by issuing the onmode -ky command.
    2. If you have shared disk (SD) servers, stop them by issuing the onmode -ky command.
    3. If you have a High-availability Data Replication (HDR) secondary server, stop it by issuing the onmode -ky command.
    4. Revert the standard server by issuing an onmode -b target_IDS_version command.
    5. Verify that reversion was successful and the server was stopped. If the reversion was not successful, check the message log for error messages, take appropriate action, and restart reversion.
  4. On each server, set the INFORMIXDIR environment variable to the full path name for the target installation.
  5. Ensure that all of the necessary configuration files are available in the target installation.
  6. Perform any additional database server reversion tasks, as described in Reverting from Informix Version 15.0.0.
  7. Start the primary server by issuing an oninit command.
  8. Start the Connection Manager by issuing an oncmsm command
  9. Start SD secondary servers by issuing oninit commands.
  10. Back up all logs. Then use ON–Bar or ontape to make a level-0 backup on the primary server to use to reestablish the RS and HDR servers if necessary.
  11. If you have RS secondary servers:
    1. Add RS entries on the primary server by issuing onmode –d add RSS rss_server_name commands.
    2. Start the RS secondary servers with level-0 restore operations from the level 0 backup that was made on the primary server after reversion.
    3. On the RS secondary servers, run the onmode -d RSS primary_server_name command, and wait for the "RSS secondary server operational" message to appear after each command.
  12. If you have an HDR secondary server:
    1. Reestablish the HDR pair on the primary server by issuing an onmode –d primary hdr_secondary_server_name command.
    2. Start the HDR secondary server with level-0 restore operations from the level 0 backup that was made on the primary server after reversion.
    3. On the HDR secondary server, run the onmode -d secondary primary_server_name command, and wait for the "HDR secondary server operational" message to appear after each command.

The reversion of all servers in the cluster is now complete.