Chapter 5. Troubleshooting

Troubleshoot and solve package-related issues after the in-place upgrade from RHEL 6.10 to RHEL 7.9.

5.1. Troubleshooting resources

You can refer to the following troubleshooting resources.

Console Output

By default, only error and critical log level messages are printed to the console output by the Pre-upgrade Assistant. To also print debug, info, and warning messages, use the --debug option with the redhat-upgrade-tool command.


The /var/log/upgrade.log file lists issues found during the upgrade phase.


The /root/preupgrade/result.html file lists issues found during the pre-upgrade phase. This report is also available in the web console. For more information, see Assessing upgrade suitability from a web UI.

5.2. Fixing dependency errors

During an in-place upgrade, certain packages might be installed without some of their dependencies.


  1. Identify dependencies errors:

    # yum check dependencies

    If the command displays no output, no further actions are required.

  2. To fix dependency errors, reinstall the affected packages. During this operation, the yum utility automatically installs missing dependencies. If the required dependencies are not provided by repositories available on the system, install those packages manually.

5.3. Installing missing packages

Certain packages might be missing after the upgrade from RHEL 6 to RHEL 7. This problem can occur for several reasons:

  • You did not provide a repository to the Red Hat Upgrade Tool that contained these packages. Install missing packages manually.
  • Certain problems are preventing some RPMs from being installed. Resolve these problems before installing missing packages.
  • You are missing NetworkManager because the service was not configured and running before the upgrade. Install and configure NetworkManager manually. For more information, see Getting started with NetworkManager.


  1. Review which packages are missing from your RHEL 7 system using one of the following methods:

    • Review the pre-upgrade report.
    • Run the following command to generate a list of expected packages in RHEL 7 and compare with the packages that are currently installed to determine which packages are missing.

      $ /root/preupgrade/kickstart/RHRHEL7rpmlist* | grep -v "#" | cut -d "|" -f 3 | sort | uniq
  2. Install missing packages using one of the following methods:

    • Locate and install all missing packages at once. This is the quickest method of getting all missing packages.

      # cd /root/preupgrade
      # bash noauto_postupgrade.d/ kickstart/RHRHEL7rpmlist_kept
    • If you know that you want to install only some of the missing packages, install each package individually.

      # yum install package

For further details about other files with lists of packages you should install on the upgraded system, see the /root/preupgrade/kickstart/README file and the pre-upgrade report.

5.4. Known issues

The following are issues known to occur when upgrading from RHEL 6 to RHEL 7:

5.5. Rolling back the upgrade

If the in-place upgrade to RHEL 7 is unsuccessful, it is possible to get the previous RHEL 6 working system back in limited configurations using one of the following methods:

5.6. Obtaining support

If you experience problems during the in-place upgrade, notify Red Hat so that these problems can be addressed. There are several methods for obtaining support.

  • Open an sosreport using one of the following methods:

    • Open a support case, select RHEL 7 as the product, and provide an sosreport from your system.
    • Generate an sosreport directly on your system:

      # sosreport

      Note that you can leave the case ID empty.

  • Submit a bug report.
  • Submit a debug log in the upgraded system in the /var/log/upgrade.log file.

For details on generating a sosreport, see the solution What is an sosreport and how to create one in Red Hat Enterprise Linux?.

For more information on opening and managing a support case on the Customer Portal, see the article How do I open and manage a support case on the Customer Portal?.