./migrate2rocky -r –

CentOS co-founder Greg Kurtzer’s new distribution becomes widely available today.

Rocky Linux 8.4 (Green Obsidian) is error compatible with RHEL 8.4 and should work as a CentOS Linux replacement.

Rocky Linux– one of at least two new distributions created to fill the void left by CentOS Linux being discontinued by parent Company Red Hat — announced today that Rocky Linux 8.4 is available. Rocky Linux 8.4 is binary compatible with Red Hat Enterprise Linux 8.4, making it possible to run applications designed and tested only for RHEL, without the need for RHEL itself.

Error to error, not just function to function

One of the recurring questions we’ve been getting since we first reported on CentOS Linux’s demise is “Why not just use [my favorite distro]?” Linux and BSD users tend to be so used to using the same software on multiple distributions, with similar package names and installers, that they forget what it’s often like to use and install proprietary software.

Rocky Linux and rival AlmaLinux (which released its own binary-compatible RHEL 8.4 clone in March) are not simply “Linux distributions, “or even “Linux distributions very similar to RHEL.” They are built from the same source code as RHEL 8.4, which ensures that a range of proprietary software with RHEL 8.4 in mind will “work” regardless of the functionality (or errors!) those packages rely on in RHEL 8.4. How vague.

Of course, Rocky Linux and AlmaLinux aren’t the only RHEL compatible options. In December, we published a partial list of binary compatible alternatives to RHEL, including RHEL’s own CentOS Stream (available only as a rolling release) and Oracle Linux, as well as CloudLinux, the parent of Rocky, Alma, and Alma.

What’s special about Rocky Linux and AlmaLinux is that both distributions were created specifically to fill the void left by CentOS. Their specific goal is to make business support available to anyone who needs them. The latter is in stark contrast to Springdale Linux – another long-running “RHEL rebuild “that should” just work.” But it is primarily designed and supported by a relatively small academic community.

How to get Rocky Linux 8.4 (Green Obsidian)

Like other Linux distributions, you can simply download an ISO for Rocky Linux and install it from scratch. But because Rocky Linux is designed to be an easy alternative to similar distributions, it also comes with easy-to-use conversion scripts.

There is currently no supported migration path from the early Release candidate (RC) releases of Rocky Linux to today’s production release — but users interested in other RHEL 8.4 binary-compatible distributions can easily migrate to obsidium in place using the free Migrate2Rocky tool, Without messing with existing users, installed software, etc. Migrate2rocky supports the following distributions.

  • 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-to-point versions “may work,” the only supported migration sources are those built specifically from RHEL 8.4 sources. In addition, the migration from RHEL 8.4 itself has issues with Katello and some error messages. We strongly recommend that interested users read the full Migrate2Rocky release notes carefully before attempting a migration, and be sure to test and back up your work before proceeding.

Safe startup will come later

Although Rocky Linux 8.4 is available today as a productable distribution, there is one notable feature that is not yet available — support for secure startup, which the Rocky team calls a “non-simple process” on the new distribution.

However, the process of enabling secure startup on Rocky is ongoing, and the team expects a second SET of ISO support for secure startup to be established and released soon. Until then, potential Rocky Linux users who can’t wait for secure startup support should consider AlmaLinux 8.4, which got its own secure startup support in May.

While there’s always an element of risk when doing in-place migration, it’s worth noting that installing a secure boot for AlmaLinux (or any other 8.4-compatible distribution) today doesn’t mean you can’t move to Rocky Linux later — if you need a secure boot today, But once Rocky Linux’s secure startup support is available, the Migrate2Rocky tool mentioned in the previous section should generally work simply, relatively quickly, and reliably.

RESF is more than Rocky Linux

In the words of the Rocky Linux team, “This is just the beginning, [The Rocky Enterprise Software Foundation] is more than Just Rocky Linux.” The team went on to describe RESF as “a home for those who believe that open source is more than a switch that can be flicked at will”.

To put their money where their mouth is, RESF hasn’t stopped offering obsidian source code — build infrastructure, Git repositories, and “anything else anyone needs to fork our work” are easy to find.

While RESF did not name any other projects, it did say that users should expect more in the coming weeks and months — a strong hint that it may assist in hosting software and projects from like-minded developers and communities in the near future.