How to Upgrade from RHEL 7 to RHEL 8

This article describes instructions on how to upgrade from Red Hat Enterprise Linux 7 to Red Hat Enterprise Linux 8 using the Leapp utility.

Requirements
An in-place upgrade to RHEL 8 is presently supported only on systems meeting the following requirements:

• RHEL 7.6 installed or above
• The Server variant
• The Intel 64 architecture
• At least 100MB of free space available on the boot partition (mounted at /boot).
• Ensure that OS full backup is completed. 

Lets start RHEL 7 Upgrade.

1. Make sure your RHEL 7 system has the Red Hat Enterprise Linux Server subscription attached.

# subscription-manager register
# subscription-manager attach --auto

2. Update all software packages to the latest version and reboot the system.

# yum update -y
# reboot

3. Once system booted, make sure to enable the Extras repository for software package dependencies.

# subscription-manager repos --enable rhel-7-server-extras-rpms

4. Install the Leapp utility.

# yum install leapp-upgrade -y

5. Now download additional required data files, which is required by the Leapp utility for a successful upgrade from RHEL 7 to RHEL 8 and place them in the /etc/leapp/files/ directory.

# cd /etc/leapp/files/
# wget https://access.redhat.com/node/3664871/5121/0/23086466
# tar -zvxf leapp-data17.tar.gz

6. First, try a preupgrade:

# leapp preupgrade 

7. Read the leapp report and fix any issues encountered.

# cat /var/log/leapp/leaap-report.txt 

   Below are issue highlighted by leapp utility for me.

# modprobe -r pata_acpi
# leapp answer --section remove_pam_pkcs11_module_check.confirm=True

8. Run the upgrade.

# leapp upgrade 

9 . Once upgrades finish, manually reboot the system.

# reboot

10. Verifying RHEL 8 Upgrade

11. Finally, verify that network services are functional by connecting to a Red Hat Enterprise Linux 8 server using SSH.

# ssh root@192.168.0.101
# cat /etc/redhat-release
# uname -r