Migrating from CentOS 7 to AlmaLinux 8

On July 01, 2024, support for CentOS 7 will end. From this date the platform and cluster nodes on servers with CentOS 7 OS are no longer supported. To keep the product support, you can change the OS of servers from CentOS 7 to AlmaLinux 8. The OS change is performed using ELevate software.

This article contains actions not intended by the CentOS developers. The OS change procedure may not perform successfully.
The platform will be unavailable during the OS change process on the server with the platform.
Virtual machines on a cluster node will be unavailable during the OS change process on that node.

Preparation

Check the compatibility of the hardware with AlmaLinux 8 OS. To do this, boot the AlmaLinux OS in Live Media mode.
If you change the OS on a cluster node, migrate virtual machines to another node. For more information, see Migration of virtual machines.
Create a backup of the platform on external storage. For more information, see Creating platform backups.

OS change

Connect to the server via SSH.

As the main CentOS repository is unavailable, specify valid mirrors in the repository settings:

sed -i s/mirror.centos.org/vault.centos.org/g /etc/yum.repos.d/*.repo

sed -i s/^#.*baseurl=http/baseurl=http/g /etc/yum.repos.d/*.repo

sed -i s/^mirrorlist=http/#mirrorlist=http/g /etc/yum.repos.d/*.repo

Install the latest available software update:
```
yum update -y
```
Reboot the server:
```
reboot
```

Install the ELevate software:

yum install -y http://repo.almalinux.org/elevate/elevate-release-latest-el$(rpm --eval %rhel).noarch.rpm

Install the Leapp framework:

yum install -y leapp-upgrade leapp-data-almalinux

Check that the system is ready for an OS change:
```
leapp preupgrade
```
Examine the output of the command and the report file /var/log/leapp/leapp-report.txt. They contain information about possible problems when changing OS.

Configure the Leapp framework:

rmmod pata_acpi

leapp answer --section remove_pam_pkcs11_module_check.confirm=True

Start the OS change:
```
leapp upgrade
```
Reboot the server:
```
reboot
```
The server may reboot longer than usual due to the OS change.
Check the OS version:
```
cat /etc/os-release
```

Actions after OS change on a cluster node

Connect to the cluster node via SSH.

Delete old repositories:

rm /etc/yum.repos.d/ispsystem-base6.repo  /etc/yum.repos.d/CentOS-QEMU-EV.repo

Connect to the server with the platform via SSH.

Change the firewall settings:

docker exec -it vm_box bash

cd /opt/ispsystem/vm

/usr/bin/ansible-playbook -i <NODE IP>:22, -e targets=all -e ansible_python_interpreter='auto_silent' -e datacenter_type='common' -e ssh_port='22' -e network_autosetup_enabled='1' -e is_lxd='0' -e dc_ips='' -e dc_ips6='' -e closed_contour='0' etc/playbooks/node/firewall.yml --timeout 60 -b

Comments to the command

Useful tips