9.2. Performing System Assessment

  1. Install preupgrade-assistant

    The preupgrade-assistant is a tool that scans through the existing RHEL 6 system and finds out how fit and ready a system is, to be upgraded to RHEL 7.
    Subscribe to the required repositories and install the preupgrade-assistant tool using the following commands:
    # subscription-manager repos --enable rhel-6-server-extras-rpms --enable rhel-6-server-optional-rpms
    # yum install preupgrade-assistant preupgrade-assistant-el6toel7
  2. Run the preupgrade tool

    Launch the preupgrade tool:
    # preupg -v
  3. Assess the results

    1. View the following result of the preupgrade tool in a browser:
      /root/preupgrade/result.html
    2. Make a note of all the components that are marked as Failed and Needs Action.
    3. Share the findings with the Red Hat executive assisting with the upgrade process.
  4. SELinux policy in RHEL 7

    SELinux policies have changed between RHEL 6 and RHEL 7. For a working SELinux policy in RHEL 7, execute the following command:
    # semodule -r sandbox
  5. Uninstall Cluster and HA related packages

    Important

    Migration is not possible with Cluster and HA related packages installed on the system.
    Uninstall Cluster and HA related packages by executing the following command:
    # yum remove modcluster ricci openais corosync