Rocky Linux—one of at least two new distributions created to fill the void left when CentOS Linux was discontinued by parent corporation Red Hat—announced general availability of Rocky Linux 8.4 today. Rocky Linux 8.4 is binary-compatible with Red Hat Enterprise Linux 8.4, making it possible to run apps designed and tested only for RHEL without RHEL itself.
Bug-for-bug, not just feature-for-feature
One of the questions we’ve gotten repeatedly since first covering CentOS Linux’s deprecation is “why not just use [my favorite distro]?” Linux and BSD users tend to be so accustomed to the same software working on multiple distributions, with similar package names and installation procedures, that they forget what using and installing proprietary software is frequently like.
Rocky Linux and competitor AlmaLinux (which released its own binary-compatible RHEL 8.4 clone in March) aren’t simply “Linux distros” or even “Linux distros which closely resemble RHEL.” They’re built from the same source code as RHEL 8.4, which guarantees that a wide array of proprietary software designed with nothing but RHEL 8.4 in mind will “just work,” regardless of how obscure a feature (or bug!) those packages depend upon in RHEL 8.4 might be.
Rocky Linux and AlmaLinux aren’t the only RHEL-compatible options out there, of course. Last December, we published a partial list of binary-compatible alternatives to RHEL, including RHEL’s own CentOS Stream (which is only available as a rolling release) and Oracle Linux, as well as Rocky, Alma, and Alma’s parent distro, CloudLinux.
What makes Rocky Linux—and AlmaLinux—special is that both distros were created specifically to fill the void left by CentOS’s deprecation. Their specific goal is to be available for anyone who needs them with commercial support also available. That latter point is in contrast with, for example, Springdale Linux—which is another long-running “RHEL rebuild” which should “just work.” But it was primarily intended for and supported by a relatively small academic community.
How to get Rocky Linux 8.4 (Green Obsidian)
Like any other Linux distro, you can simply download an ISO of Rocky Linux and install it from scratch. But since Rocky Linux is specifically intended to serve as an easy replacement for similar distributions, it comes with easy-to-use conversion scripts as well.
There is no supported migration path from one of Rocky Linux’s earlier release candidate (RC) builds to today’s production build—but interested users of other RHEL 8.4 binary-compatible distributions can use the free migrate2rocky tool for convenient, in-place migration to Green Obsidian that should not mess up existing users, installed software, etc. The following distributions are supported by
- AlmaLinux 8.4
- CentOS Linux 8.4
- RHEL 8.4
- Oracle Linux 8.4
The Rocky Linux team warns that while migrations from other point releases “may work,” the only supported migration sources are those specifically built from RHEL 8.4 source. There are also issues with Katello and some error messages associated with migrations beginning with RHEL 8.4 itself. We strongly recommend interested users carefully read the full
migrate2rocky release notes prior to attempting a migration—and, as always, have tested and working backups available before proceeding!
Secure Boot will come later
Although Rocky Linux 8.4 is offered as a production-ready distribution today, one notable feature isn’t available yet—support for Secure Boot, which the Rocky team describes as a “non-trivial process” to get going on a new distribution.
The process of enabling Secure Boot with Rocky is underway, however, and the team expects a second set of ISOs with Secure Boot support to be built and released relatively soon. Until then, potential Rocky Linux users who can’t wait for Secure Boot support should consider AlmaLinux 8.4, which received its own Secure Boot support this May.
Although there is always some element of risk when doing in-place migrations, it’s worth noting that installing AlmaLinux (or another 8.4 compatible distro) with Secure Boot today does not mean you can’t shift over to Rocky Linux later—the
migrate2rocky tool referenced in the last section should typically work simply, relatively quickly, and reliably if you need Secure Boot today but still prefer Rocky Linux once its Secure Boot support becomes available.
The RESF is more than Rocky Linux
In the words of the Rocky Linux team, “this is just the beginning, and the [Rocky Enterprise Software Foundation] is more than just Rocky Linux.” The team goes on to describe the RESF as “a home for those that believe that open source isn’t just a switch that can be toggled at will.”
In order to put its money where its mouth is, the RESF didn’t stop with making Green Obsidian’s source code available—the build infrastructure, Git repos, and “everything else anyone would need to fork our work” is easy to find.
Although the RESF hasn’t specified any other projects by name, it says that users should expect more in the coming weeks and months—strongly implying that it may assist in hosting software and projects from like-minded developers and communities in the near future.