Convert CentOS to Alma Linux

Table of Contents
Intro
Prerequisites
Converting CentOS to Alma Linux

Intro

In December 2020, RedHat announced that they would end support for CentOS 8 on December 31, 2021. CentOS 8 was previously going to remain in support until May 31, 2029.

While there are several binary-compatible alternatives to CentOS, we have identified Alma Linux as the distribution that is the industry replacement for CentOS, and so it is the one we now support.

This document describes the steps to convert your GreenArrow server’s operating system from CentOS 8 to Alma Linux 8.

Prerequisites

This procedure should only be executed by an experienced Linux systems administrator.
While we do not have any reason to expect issues running any CentOS 8 version of GreenArrow on Alma Linux 8, our testing started with GreenArrow v4.235.0, so we recommend updating GreenArrow to at least v4.235.0 before beginning the conversion process.
If you are not yet familiar with Alma Linux, we recommend reading about the distribution and familiarizing yourself with the conversion process before proceeding.

Converting CentOS to Alma Linux

The time it takes your conversion to run will depend on the hardware you are running and your familiarity with the required command-line tools, but the process typically took around 15 minutes in our testing.

Here are the steps:

Back up GreenArrow using the unmanaged backup script. We strongly recommend storing a copy at a location external to the server so that you can use it to recover if something goes wrong during the conversion process.
Stop GreenArrow and use hvmail_init to verify that GreenArrow’s services are down.
Use the documentation provided by Alma Linux to convert your CentOS 8 server to Alma Linux 8
Start GreenArrow and use hvmail_init to verify all of GreenArrow’s services are running.
Perform any tests you need to confirm GreenArrow to make sure it is working. The final testing steps in our installation documentation is a good place to start.