Chapter 1. Planning an upgrade

An in-place upgrade is the recommended way to upgrade your system to a later major version of RHEL.

To ensure that you are aware of all major changes between RHEL 6 and RHEL 7, consult the Migration Planning Guide before beginning the in-place upgrade process. You can also verify whether your system is supported for an in-place upgrade by running the Preupgrade Assistant. The Preupgrade Assistant assesses your system for potential problems that could interfere or inhibit the upgrade before any changes are made to your system. See also Known Issues.

Note

Once you perform an in-place upgrade on your system, it is possible to get the previous working system back in limited configurations of the system by using the Red Hat Upgrade Tool integrated rollback capability or by using suitable custom backup and recovery solution, for example, by using the Relax-and-Recover (ReaR) utility. For more information, see Rolling back the upgrade.

This RHEL 6 to RHEL 7 upgrade procedure is fully supported if your RHEL system meets the following criteria:

  • Red Hat Enterprise Linux 6.10: Your system must have the latest RHEL 6.10 packages installed.

  • Architecture and variant: Only the indicated combinations of architecture and variant from the following matrix are supported:

    Product VariantIntel 64-bit architectureIBM POWER, big endianIBM Z 64-bit architectureIntel 32-bit architecture

    Server Edition

    Supported

    Supported

    Supported

    Unsupported

    HPC Compute Node

    Supported

    N/A

    N/A

    Unsupported

    Desktop Edition

    Unsupported

    N/A

    N/A

    Unsupported

    Workstation Edition

    Unsupported

    N/A

    N/A

    Unsupported

    Server running CloudForms software

    Unsupported

    N/A

    N/A

    N/A

    Server running Satellite software

    Unsupported. To upgrade Satellite environments from RHEL 6 to RHEL 7, see the Red Hat Satellite Installation Guide.

    N/A

    N/A

    N/A

    Note

    Upgrades of 64-bit IBM Z systems are supported unless Direct Access Storage Device (DASD) with Linux Disk Layout (LDL) is used.

  • Supported packages: The in-place upgrade is supported for the following packages:

    • Packages installed from the base repository, for example, the rhel-6-server-rpms if the system is on the RHEL 6 Server for the Intel architecture.

    • The Preupgrade Assistant, Red Hat Upgrade Tool, and any other packages that are required for the upgrade.

      Note

      It is recommended to perform the upgrade with a minimum number of packages installed.

  • File systems: File systems formats are intact. As a result, file systems have the same limitations as when they were originally created.
  • Desktop: System upgrades with GNOME and KDE installs are unsupported. For more information, see Upgrading from RHEL 6 to RHEL 7 on Gnome Desktop Environment failed.
  • Virtualization: Upgrades with KVM or VMware virtualization are supported. Upgrades of RHEL on Microsoft Hyper-V are unsupported.
  • High Availability: Upgrades of systems using the High Availability add-on are unsupported.
  • Public Clouds: The in-place upgrade is unsupported for on-demand instances on Public Clouds.
  • Third-party packages: The in-place upgrade is unsupported on systems using third-party packages, especially packages with third-party drivers that are needed for booting.
  • The /usr directory: The in-place upgrade is unsupported on systems where the /usr directory is on a separate partition. For more information, see Why does Red Hat Enterprise Linux 6 to 7 in-place upgrade fail if /usr is on separate partition?.