Does the choice of enterprise Linux really matter anymore?

We speak to Canonical, Red Hat and SUSE about the place of Linux in a cloud-based future - and what the CentOS EOL foretells

As compute moves up the stack and out to the edge, we speak to representatives of the three largest enterprise Linux firms to see how they view the future.

Consolidation is coming - or is it?

Nicholas Dimotakis, VP of field engineering at Canonical, believes that a major consolidation of Linux is coming.

As he sees it, the focus is shifting up the stack, with enterprises interested in containerised applications running on Kubernetes, and in fire-and-forget functions on serverless platforms like AWS Lambda in which the infrastructure is magicked away. In this scenario, the operating system becomes just one more component, a lower-level abstraction.

"The Linux ecosystem is going to consolidate," Dimotakis said. "You don't need as many Linux distributions anymore. Why? Because people are focusing on the higher layers. Now, containers, Functions-as-a-Service, for example, they don't really need to care about the operating system, they just need something they know works."

Another way of putting this might be that competition between enterprise Linux vendors (those offering paid-for versions of what otherwise can be had for free) is about to hot up.

According to Dimotakis, Canonical has a head-start in this race with what he claims is the largest presence in the cloud native environment, with Ubuntu underpinning the big public cloud providers as well as being present in many Kubernetes distributions and containers.

On the possibility of Linux consolidation, Mike McGrath, vice president Linux engineering at Red Hat, believes there's still plenty of space for all comers. The total number of distros is not important, he argues, "as long as innovation and development remains in the upstream and does not create fragmentation. Choice matters."

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Gerald Pfeifer, CTO at SUSE and openSUSE chair of the board, concurred. The growth of Linux in the cloud, on premises and at the edge provides ample space for a variety of distros created by enthusiasts. Then again, for core enterprise use it's a different matter.

"Creating and, let's not forget, maintaining an enterprise-class distribution is hard; it's a lot of work, and I expect that landscape to remain rather stable," he explained.

"That said, enterprise and community distributions connecting more closely, as we are doing with SUSE Linux Enterprise and openSUSE, may be an emerging trend and drive innovation on both sides."

Differentiators in the edge age

Linux is right at the heart of cloud, containers and Kubernetes, but at its core, Linux is Linux with distributions differentiated by package managers, bundled applications and the size and effectiveness of their supporting communities - as well as paid-for services, support and features in the premium versions, of course.

So if we accept that the focus is moving up the stack does it matter which distribution is used, particularly as each layer is abstracted from those below?

Dimotakis puts the emphasis on reliability, seeing Ubuntu's prevalence in the major cloud platforms and further up the stack as a major selling point.

"With most companies are trying to move to containers now, the container engine in the three main public clouds is actually Ubuntu underneath. And it's the basis of what the native Kubernetes is in every public cloud.

"Because they are based on Ubuntu, the interoperability between the Kubernetes worker nodes and the containers is basically guaranteed. The theory goes that these layers are completely abstracted, but there are always issues that could happen, just because things are slightly different."

For Pfeifer the choice of distribution - and therefore vendor - remains important because it's all about support across the ecosystem.

"You carefully select a stack - applications, development tools, supporting components, and the operational infrastructure which these days usually includes Kubernetes, Linux and management tools."

"And much like your choice of hardware or cloud service providers still matters, so does the choice of your Kubernetes, Linux and systems management provider. Are you looking for adaptability and flexibility, support and life cycle, and a broader ecosystem, for example?"

For Red Hat, whose OpenShift hybrid cloud Kubernetes distribution was largely the factor behind its record-breaking $34 billion acquisition by IBM, McGrath made a similar point.

"Keep in mind that what runs in the container is an operating system and what the container runs on is an OS. This causes the interactions between application (in the container) and the hardware to become more complex, and as such the OS matters more than ever. Also, as deployments get more complicated across on-premise, public clouds and out to the edge, the OS is what delivers consistency and efficiency of deployment. Again, making the OS decision even more important."

This informs Red Hat's business model in the cloud era.

"The choice of the operating system is a strategic decision. It either enables optionality in the future or it becomes a limiter," McGrath went on.

"Our subscription model is built to deliver continuous value throughout the life of that subscription, including capabilities from online services like Red Hat Insights that are included as part of that subscription. The standard subscription model is complimented by a number of programmes that enable contributors of the ecosystem to participate and collaborate. Key folks like developers or open source projects for whom we have special programmes."

Likewise for SUSE it's all about accommodating changes in the big picture.

"Our focus remains supporting users in simplifying their existing landscapes, helping them modernise towards a world where cloud and edge are becoming ever more relevant, and having their back as they accelerate their (digital) transformation," Pfeifer said.

"Along this path we have been adding containers, Kubernetes, and the management of classic Linux workloads and Kubernetes - and not just those under the SUSE brand - to our mix. In parallel, we have been focusing on edge computing and enabling developers and operators when it comes to AI."

The demise of CentOS

In support of the Linux consolidation theory, Canonical's Dimotakis put forward the case of CentOS.

CentOS is a downstream version of Red Hat Enterprise Linux, meaning that it has all the new features added by Red Hat but without the paid-for support package attached to the enterprise version. CentOS was very popular among engineers who could benefit from its stability without the support package, but last year Red Hat announced it would no longer support the distribution, offering instead a new version called CentOS Stream, an upstream distribution of cutting-edge features that may make it into the next RHEL update. This is obviously a very different beast, and the original CentOS developers have been working on Rocky Linux, a replacement for the stable CentOS, but so far without having released any code. CentOS reaches end-of-life in December.

The development, while disappointing for CentOS users, has been positive for Canonical, said Dimotakis.

"There were always too many operating systems for IBM. One of IBM has monetisation strategies - or let's call it a monetisation pivot - was this one. IBM basically needs to make their money back - they paid a lot for Red Hat - so essentially the idea is that you either come to their paid-for RHEL distribution or you go somewhere else. And that of course, alienated a lot of users."

Some of those users from large organisations are migrating to Ubuntu he claims. "This was kick to them to basically say, well, maybe we should actually consider Ubuntu as an enterprise Linux option for us."

Pfeifer said that SUSE has also seen movement in this direction.

"I definitely have seen some interest in openSUSE and SUSE distributions by former CentOS users. For some this was a trigger to look into a supported solution from SUSE. Others decided to have a look at openSUSE. And in a way isn't that the nature of open source? Flexibility and choice?"

Unsurprisingly, Red Hat's McGrath offered a different take.

"We have been seeing great interest from customers and partners that want to collaborate with us, and we're happy with the progress in CentOS Stream as we begin our work on Red Hat Enterprise Linux (RHEL) 9.

"For those on the downstream CentOS Linux, there's a variety. Some are still on CentOS and assessing options of what to do next. Some have moved to CentOS Stream, RHEL or one of the new no- or low-cost RHEL programs like the Red Hat Developer Program. Some have said they are moving to other distros. We're doing what we can to ensure that CentOS Linux users have a smooth transition into the right place in the larger Enterprise Linux ecosystem."

This article is based on a telephone interview with Nicholas Dimotakis and questions subsequently emailed to Red Hat and SUSE.