Red Hat Enterprise Linux is a solid platform, but for a lot of estates the per-socket subscription is paying mainly for binary compatibility and a support line you rarely call. When Red Hat moved CentOS to the upstream Stream model, it removed the free, bug-for-bug RHEL rebuild that many teams used for non-critical systems, and pushed the community to create replacements. Two of those, Rocky Linux and AlmaLinux, are now mature, widely deployed, and specifically designed to be 1:1 compatible with RHEL. If your reason for paying Red Hat is compatibility rather than a genuine need for Red Hat’s support and certifications, they are worth a serious look.
Rocky vs AlmaLinux: a close call, deliberately
Both projects exist to be drop-in RHEL rebuilds, both track RHEL releases closely, and both ship free in-place converters. The differences are mostly about governance and compatibility philosophy.
Rocky Linux, from the Rocky Enterprise Software Foundation, was founded by a CentOS co-founder and aims for strict bug-for-bug RHEL compatibility. AlmaLinux, from the AlmaLinux OS Foundation, targets ABI compatibility with RHEL rather than a strict 1:1 rebuild, which has let it keep shipping compatible releases even as Red Hat changed source availability, and it also maintains ELevate for cross-major upgrades. For most workloads either is fine; the choice often comes down to which foundation’s approach and community you trust for the long haul.
What migrating actually involves
For same-major moves (RHEL 8 to Rocky/Alma 8, or 9 to 9), both distributions provide in-place converters, migrate2rocky and almalinux-deploy, that swap the RHEL packages, repos, and branding without reprovisioning. Snapshot first, run the converter, validate, and de-register the host from Red Hat Subscription Manager to stop the billing. Crossing a major version is a reprovision, not a converter job, so plan those as fresh builds via kickstart and Ansible.
Because effort is genuinely low here, the decision is less “can we?” and more “which, and how do we validate at fleet scale?” Each path below opens to a full cost model, plan, and in-depth guide.