Which Linux distributions does LinuxONE actually run? Take your pick! You can choose from a wide range of officially supported and community-driven distributions.
When you first learn about IBM LinuxONE, many of the resources talk about security, resiliency, open source, and innovation. These benefits have been covered extensively. But on a practical level, what distribution of Linux does LinuxONE actually run?
First, let’s back up for a moment. From a Linux perspective, LinuxONE is a mainframe (like its sister IBM Z, often referred to as the s390x architecture in the open source world) that IBM has developed to exclusively run Linux. This is enforced through specific Integrated Facility for Linux (IFL) processors that only run Linux, and do not run some of your more traditional mainframe operating systems, like IBM z/OS. From there, you can run Linux directly on a Logical Partition (LPAR) from the Processor Resource/System Manager (PR/SM), but more commonly you'd run it on IBM z/VM or KVM. Once that decision is made, you can install Linux.
Figure 1 illustrates a slice of a LinuxONE system, showing how you can run Linux directly on an LPAR, or on z/VM (KVM may also be used)
Figure 1. Linux running on LinuxONE
Linux distribution selection is up to you! Aside from the need for it to be built for the architecture, there is no one distribution of Linux that is written to be the default for LinuxONE.
Officially supported areSUSE Enterprise Linux Server (SLES), Red Hat Enterprise Linux (RHEL), and Ubuntu. Beyond that, there are several community-driven distributions, including openSUSE, Fedora, Debian, Alpine, AlmaLinux, and Rocky Linux.
Each distribution builds as many software packages as possible to provide a comprehensive experience, which means there are thousands of packages to choose from on each distribution. However, from time to time you may find a package that is missing compared to what you’d expect to find on x86. This is typically due to the software not building properly for the architecture, or because the software was very specific to an x86 environment. If you run into this, you can try building the software yourself and have a look at the continuously updatedValidated Open Source Software list for IBM LinuxONE and Linux on IBM Z. This table links to container images and build instructions for popular pieces of software that are continuously validated, as well as newer versions of software that have not yet made it into the distributions.
Ready to get started now? Each distribution has published installation guides to get you on your way on your own LinuxONE system. If you don’t yet have a LinuxONE system available to you and you’re interested in checking out how open source software you use (or that you’ve written!) works on it, you can check out the LinuxONE Community Cloud for a free VM running SLES, RHEL, or Ubuntu.