How to migrate from CentOS 7.x to AlmaLinux

1

hey folks,

I hope all doing well

I have some servers running CentOS 7.x, I think of migrating some to go testing and familiarizing with AlmaLinux.

How I can migrate from CentOS 7.x to AlmaLinux 8.x without reinstall all system ?

Like the migration from CentOS to CloudLinux or from CloudLinux to CentOS

very thanks,
Rodrigo Araujo

2

@itmnetworks nice to meet you. Respectfully, do not accept my answer is authoritative; however, with my experience dealing with CentOS since major version 5 and every other major version including 8 and the fact this is a forked project from CentOS (for historical reference)…

You cannot upgrade from one major version to the next major version. I learned this statement is true for each and every major version of CentOS, because I would ask each major version so that I had my expectations set for me and so too my understanding of the philosophy in various design aspects.

So, to familiarize yourself with AlmaLinux 8.x, you need to install AlmaLinux 8.x.

I would love to know if my understanding of the philosophy in design of CentOS is being followed with AlmaLinux as well.

Let’s see what they come back with.

3

Upgrade to centos 8. (Not the stream version), then upgrade to Alma 8. The Alma upgrade script does not support version 7.

4

I saw here, the best way is: install a new server and migrate the clients

very thanks

1 Like
5

The answer by @warron.french is correct. There is no upgrade procedure between major versions.

Even redhat has issues with RHEL upgrades, they created an upgrade script for paid clients but that was limited in scope and can’t handle all packages. If you look at the differences between major versions, you’ll see that while some packages remain the same, most packages receive significant changes over the years. This prevents them from automated upgrades, for example Apache version 2.2 to 2.4 requires significant manual changes.

Personally, I’ve migrated from CentOS 5 to 6, then to 7 and now to 8, by following some simple rules. For desktops, everything is under /home and system modifications are stored in Ansible playbooks. For servers, I use a hosting script that makes a complete backup of each hosted site and restores the backup file on the new server. A good migration plan should allow you to upgrade major versions with no real issues.

1 Like