Chapter 6. Verifying the post-upgrade state of the RHEL 9 system

Prerequisites

• The system has been upgraded following the steps described in Performing the upgrade from RHEL 8 to RHEL 9 and you have been able to log in to RHEL 9.

• Verify that the current OS version is RHEL 9:

  # cat /etc/redhat-release
  Red Hat Enterprise Linux release 9.0 (Plow)

• Check the OS kernel version:

  # uname -r
  5.14.0-70.10.1.el9_0.x86_64

  Note that .el9 is important and the version should not be earlier than 5.14.0.

• If you are using the Red Hat Subscription Manager:

  • Verify that the correct product is installed:

    # subscription-manager list --installed
    +-----------------------------------------+
        	  Installed Product Status
    +-----------------------------------------+
    Product Name: Red Hat Enterprise Linux for x86_64
    Product ID:   479
    Version:      9.0
    Arch:         x86_64
    Status:       Subscribed

  • Verify that the release version is set to 9.0 immediately after the upgrade:

    # subscription-manager release
    Release: 9.0

• Verify that network services are operational, for example, try to connect to a server using SSH.
• Check the post-upgrade status of your applications. In some cases, you may need to perform migration and configuration changes manually. For example, to migrate your databases, follow instructions in Configuring and using database servers.