How to migrate CentOS 8 to Rocky Linux

CentOS Linux 8 is about to meet it’s early end of life on 31 Dec 2021. Therefore, you should learn how to migrate CentOS 8 to Rocky Linux. #centlinux #linux #rockylinux

Why Migrate to Rocky Linux?:

CentOS Linux 8 is no more, and the fans are eagerly looking for alternatives. Rocky Linux is the most anticipated downstream fork of Red Hat Enterprise Linux 8. The project is led by Gregory Kurtzer, founder of the CentOS project. Therefore, fans are expecting that the Rocky Linux may be the best alternative of CentOS Linux 8.

Just like CentOS, Rocky Linux is also a community enterprise operating system designed to be 100% bug-for-bug compatible with America’s top enterprise Linux distribution i.e Red Hat Enterprise Linux.

Environment Specification:

We are using a minimal CentOS 8 virtual machine with following specifications.

• CPU – 3.4 Ghz (2 cores)
• Memory – 2 GB
• Storage – 40 GB
• Operating System – CentOS 8.3
• Hostname – centos-linux-8.centlinux.com
• IP Address – 192.168.116.230 /24

Verifying Existing CentOS Linux OS:

Connect with centos-linux-8.centlinux.com as root user by using a ssh client.

Check the current operating system name and version.

# cat /etc/os-release
NAME="CentOS Linux"
VERSION="8"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="8"
PLATFORM_ID="platform:el8"
PRETTY_NAME="CentOS Linux 8"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:8"
HOME_URL="https://centos.org/"
BUG_REPORT_URL="https://bugs.centos.org/"
CENTOS_MANTISBT_PROJECT="CentOS-8"
CENTOS_MANTISBT_PROJECT_VERSION="8"

Check the Linux Kernel version by using uname command.

# uname -r
4.18.0-240.1.1.el8_3.x86_64

Migrate CentOS 8 to Rocky Linux:

Thanks to migrate2rocky.sh script, migration process is now pretty straight forward. By running this script you can easily migrate CentOS 8 to Rocky Linux.

You can download migrate2rocky.sh script from GitHub, it’s free.

Execute the wget command to download migrate2rocky.sh script straight from the Linux CLI.

# wget https://raw.githubusercontent.com/rocky-linux/rocky-tools/main/migrate2rocky/migrate2rocky.sh
--2021-07-02 18:58:34--  https://raw.githubusercontent.com/rocky-linux/rocky-tools/main/migrate2rocky/migrate2rocky.sh
Resolving raw.githubusercontent.com (raw.githubusercontent.com)... 185.199.111.133, 185.199.109.133, 185.199.110.133, ...
Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|185.199.111.133|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 28338 (28K) [text/plain]
Saving to: ‘migrate2rocky.sh’

migrate2rocky.sh    100%[===================>]  27.67K  --.-KB/s    in 0.07s

2021-07-02 18:58:37 (410 KB/s) - ‘migrate2rocky.sh’ saved [28338/28338]

To make downloaded file executable, you need to set execution permissions on it.

# chmod +x migrate2rocky.sh

Check the migrate2rocky.sh command usage by executing following command.

# ./migrate2rocky.sh -h
Usage: migrate2rocky.sh [OPTIONS]

Options:
-h Display this help
-r Convert to rocky
-V Verify switch
   !! USE WITH CAUTION !!

Execute migrate2rocky.sh script to start migration of your Linux operating system.

# ./migrate2rocky.sh -r

The script first checks the CentOS 8 yum repositories in use, and then replace these repositories with Rocky Linux equivalent.

The migration script also look for the system packages that corresponds to the CentOS Linux 8 branding such as logos, backgrounds and license. And then replace it with Rocky Linux equivalent to change the look and feel of your operating system.

Besides migration, the migrate2rocky.sh script also upgrades the Linux server to latest stable releases.

The script takes couple of minutes to complete, depending upon your Internet connection speed. For us it take about an hour to complete. So sit back and relax for a while.

After successful completion of migrate2rocky.sh script, you need to reboot your system with the new Linux Kernel.

# reboot

During reboot, your GRUB boot menu will show a new entry pertains to the new Rocky Linux 8 Kernel. Press <ENTER> to start your operating system with this new Kernel.

After reboot, execute following command at Linux bash prompt to check the current operating system version and name.

# cat /etc/os-release
NAME="Rocky Linux"
VERSION="8.4 (Green Obsidian)"
ID="rocky"
ID_LIKE="rhel fedora"
VERSION_ID="8.4"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Rocky Linux 8.4 (Green Obsidian)"
ANSI_COLOR="0;32"
CPE_NAME="cpe:/o:rocky:rocky:8.4:GA"
HOME_URL="https://rockylinux.org/"
BUG_REPORT_URL="https://bugs.rockylinux.org/"
ROCKY_SUPPORT_PRODUCT="Rocky Linux"
ROCKY_SUPPORT_PRODUCT_VERSION="8"

You can see that your operating system is migrated from CentOS 8 to Rocky Linux.

Also check the Linux kernel version.

# uname -r
4.18.0-305.7.1.el8_4.x86_64

The script has also upgraded your Linux Kernel to the latest stable version support by your operating system.

Conclusion:

In this Linux tutorial, you have learned how to migrate CentOS 8 to Rocky Linux. There are some other good CentOS alternatives, and you can find the respective migration guides at CentLinux.