The Rocky Enterprise Software Foundation (RESF) is announcing the general availability of Rocky Linux, release 8.4, designed as a drop-in replacement for the soon-to-be discontinued CentOS. The GA release is launching six-and-a-half months after Red Hat deprecated its support for the widely popular, free CentOS server operating system.

The Rocky Linux development effort – named as a tribute to late CentOS co-founder Rocky McGaugh – was started by Gregory M. Kurtzer, co-creator of CentOS, and the inventor of Singularity and Warewulf.

Free community support for Rocky Linux is available through the RESF via Mattermost (an open source Slack alternative), IRC and via the Rocky Linux site forums.

Paid commercial support is available through CIQ (previously known as Ctrl IQ), an HPC startup that Kurtzer founded last year that is leveraging Rocky and other tools to build a cloud-native, meta-orchestration platform. Kurtzer is CEO of CIQ as well as founder and executive director of Rocky Linux.

Kurtzer told HPCwire he was thinking about creating a new version of CentOS ever since Red Hat acquired it in 2014. “And then when IBM acquired it, you know, I was thinking about it even more, and then when [CentOS was canceled], it seemed pretty clear that this needs to happen.”

Indeed, Kurtzer wasted no time. Red Hat announced it was shifting focus from downstream build CentOS to upstream build CentOS Stream on December 8, 2020, and the very next day the Rocky Linux development effort was launched on Github.

The project quickly gained traction. Over 650 contributors joined in less than 24 hours, and the Slack ballooned to about 10,000 people in two months.

“The harder problem to solve here was not building the operating system, it was building the infrastructure to build the operating system,” Kurtzer semi-joked.

He revealed it took four months to get the infrastructure and organization hammered out and about two months to build the operating system.

Rocky Linux bootstraps off of CentOS. It uses the same sources as Red Hat Enterprise Linux, leveraging CentOS Stream.

“We’re feeling extremely confident that we have a very stable, very rock solid operating system,” Kurtzer said.

Independent and Community supported

Originally the plan was to develop Rocky Linux within CIQ, but Kurtzer said very quickly the founders pivoted to making it a true community open source project.

“You guarantee stability in what you’re creating, not controlling it by one company, but by having control of it across many companies,” he said.

Amazon, Google and other major tech vendors – including hardware companies – are backing the project.

“We have AWS, we have Google Cloud, and [other big names] – when’s the last time you heard them all coming to the table to work together on something? Not one of them is going to ever allow this operating system to benefit one more than the other. Right? And that gives it the stability,” said Kurtzer.

While CIQ is the founding services and support partner, Kurtzer acknowledges that others may follow, and the model supports that.

Rocky Linux – designed to be bug-for-bug compatible with Red Hat Enterprise Linux – fills a gap left by the loss of a stable, free CentOS (CentOS 8 support ends December 31, 2021) and CIQ lowers the barrier to entry, cost-wise, for a supported distro. Additionally, there is no operating system change required to add support for Rocky, unlike the shift from CentOS (or CentOS Stream) to Red Hat Enterprise Linux, which while they are very similar is still an operating system change.

“We are going to go much wider in terms of customer base,” Kurtzer said. “And we’ve already gotten validation by a number of organizations, very large enterprise organizations that are looking to do this, and we are talking with hardware vendors as well about teaming up on this.”

Kurtzer said he is confident that the Rocky Linux organization can scale to meet demand post-GA. The biggest demand has already hit, he said. Now they are focused on maintenance and organizing special interest groups (SIGs).

“We’ll be focused on making sure updates happen immediately and making sure we have a good process flow for getting the updates out there,” said Kurtzer.

An HPC-SIG is being formed to address the needs of the high-performance computing community. It will bring in different software, MPI, Slurm, Torque and so forth.

There is discussion about directly integrating OpenHPC. “It should be possible to just have a single package in there that references OpenHPC. So if somebody wanted to install OpenHPC on top of their Rocky system, it should literally only require a couple of commands.”

Kurtzer expects additional SIGs to form that will work on extending Rocky for other verticals, for example EDA and hyperscale. The functionality would be optional on top of the bug-for-bug compatible version; it would not be enabled by default.

While it’s not possible to know exactly how many people have downloaded or are using Rocky Linux since there are a dozen mirror sites, RESF estimates that the Rocky Linux beta has been used and downloaded and installed a quarter of million times, roughly extrapolating from the 100,000 downloads from the tier zero mirror.

The 8.4 GA release supports x86_64 and the ARM64 (aarch64) architectures and can be downloaded at https://rockylinux.org/download. RESF intends to support Rocky Linux 8 through June 2031.

Related coverage: Red Hat’s Disruption of CentOS Unleashes Storm of Dissent