Getting Linux on POWER up and Running is Simple

Edit: It is still simple.

Originally posted January 2019 by IBM Systems Magazine

Many organizations operating with AIX* and IBM i environments also rely on Linux* to run their businesses. But even if you know Linux, you may not realize how easy it is to run the OS on IBM Power Systems* servers.

In larger enterprises, maybe there’s a dedicated AIX team and another team of Linux administrators, with everyone doing their own thing. The AIX group isn’t focused on Linux, and the Linux folks don’t know what Power Systems servers are capable of.

Some believe that running Linux on enterprise hardware is too costly or complex. It’s not. Others don’t realize that running Linux on POWER* is even an option.

Depending on your workload characteristics, Linux performance can be significantly better when run on POWER. It’s also worth noting that IBM has worked to make this option even more appealing. Since the POWER8* processor was introduced, IBM has been transitioning the processor to fully support the little endian format. This makes it easier for application providers to recompile and run Linux on POWER without making changes to their source code. As a result, more distributions, packages and applications are being migrated to Power Systems servers all the time.

Given the affordability of open source, you owe it to your enterprise to consider Linux on POWER and to get hands-on with various Linux distributions. That way, you’ll be able to provide meaningful input when your company discusses the pros and cons of available choices.

An Array of Choices

Numerous Linux distributions are available. Some of the more widely used distributions include Ubuntu, SUSE and Red Hat (the company IBM plans to acquire). But any number of other distributions, such as CentOS, Debian and Fedora, don’t require licensing or support fees.

It’s critical to choose a distribution that’s been compiled for and works on Power Systems hardware—but beyond that, the choices are wide open. As all of these distributions are made up of open-source code, they stand out in different ways. Maybe you’ll find it easiest to work with a particular desktop manager, default filesystem type or package manager. Each distribution is unique, of course, but once you’re proficient with one, working with others is fairly easy.

A Familiar Process

If you’ve not experimented with Linux on POWER, here are some things to consider.

First, installing Linux is similar to installing AIX, so if you’re familiar with that process, you shouldn’t have any issues. Choose a distribution and download the appropriate .iso image.

For instance, a web search on “Ubuntu download Power” returns options to download various Ubuntu versions: There’s Ubuntu 18.04 LTS for IBM Power*, the first release to support POWER9*, and Ubuntu 16.04 LTS and Ubuntu 14.04 (both are for POWER8*). SUSE is similar, although you must register for a 60-day free trial. On Red Hat’s website, you can request an evaluation.

In all instances, be sure you’re getting the install images for ppc64le, and if you’re going to run on POWER9, be sure that the latest processor is supported.

I’m assuming your testing will occur on a traditional Power Systems server with some spare capacity. I’m further assuming you’re running a VIO server, and that you’ve obtained the necessary permissions from your IT management. Testing is even easier if you have either a Linux-only variant of Power Systems hardware—for instance the L922—or hardware acquired from an OpenPOWER community vendor, such as Raptor Computing Systems’ Talos II.

On a traditional system, the installation process begins by copying the .iso image that you downloaded to the virtual media repository in your VIO server. This allows you to boot from a virtual DVD over vSCSI. Then you can either have your SAN administrator provide a LUN that you can use for testing, or you can map a spare disk in your frame to an LPAR, or you can carve up a logical volume in your VIO server to use as a backing device for your Linux installation. Again, all this is familiar for anyone who’s installed AIX.

To make this LPAR available to your network, obtain the appropriate IP address information. While you won’t need much processing power or memory, sizing your test LPAR appropriately will obviously lead to better results.

Once your LPAR is defined, simply boot from your virtual DVD. In many cases, the defaults listed in the various installer menus will be sufficient, but it’s worth taking the time to familiarize yourself with the Linux environment by going through the various menus and trying different settings and options. Practice setting up repositories and user IDs, make changes to filesystems, load software and configure the system.

After going through this process a few times with one distribution, try another. Incidentally, this is why having access to a “crash and burn” test system is critical; you can do what you want without impacting others.

To install Linux as a client hosted by IBM i, view the “IBM Support” document listed in the “Linux on POWER References,” below.

Simple, Seamless

If you allow users on your system, in most cases, they won’t even realize that Linux is running on POWER as opposed to the x86 hardware they may be accustomed to—but they could notice the improved performance. You have the hardware, and getting Linux up and running on it is a simple process.

IBM Power Systems L922 benchmark information: ibm.co/2Teo8zC

Little endian primer: ibm.co/2DFkudC

IBM Redpaper (REDP5496): “IBM Power System L922: Technical Overview and Introduction”: ibm.co/2FA6Km6

OpenPOWER Foundation: bit.ly/2BdsHDD

IBM Support: Create a client partition (i, AIX or Linux) hosted by an IBM i server partition using HMC Classic: ibm.co/2FqpMvt