CentOS Linux is a special case among migrations because it is not a cost decision, it is an end-of-life one. CentOS Linux 8 reached end of life at the end of 2021, and CentOS Linux 7 followed in mid-2024. Neither receives security or bug fixes any more, and CentOS Stream, the rolling preview of what will become the next RHEL, is deliberately not the stable, bug-for-bug rebuild that teams standardized on. Running an unpatched, out-of-support OS is a genuine compliance, audit, and security liability, which is why “what do we replace CentOS with?” became an urgent question rather than a nice-to-have.
The two natural successors
Both Rocky Linux and AlmaLinux were created specifically to fill the gap CentOS left: free, community-governed, and 1:1 compatible with RHEL, so your existing packages, scripts, and config management keep working. This is the closest thing to a like-for-like continuation of what CentOS Linux was. Rocky aims for strict bug-for-bug RHEL compatibility; AlmaLinux targets ABI compatibility and maintains the ELevate tooling for cross-major upgrades. For a CentOS estate, either restores you to a supported, patched, RHEL-compatible baseline.
CentOS 7 vs CentOS 8: different migrations
The version you are on changes the work substantially. CentOS 8 or Stream can be converted in place: Rocky’s migrate2rocky.sh and AlmaLinux’s almalinux-deploy.sh swap the distribution under a running system after a snapshot, no reprovisioning required. CentOS 7 is harder, because there is no in-place jump across a major version. You either use AlmaLinux’s ELevate (built on Red Hat’s leapp) to move 7 to 8 and then deploy fresh on 9, or you reprovision directly onto Rocky/Alma 8 or 9 via kickstart and redeploy your workloads with Ansible. Treat CentOS 7 hosts as rebuilds and budget accordingly.
The urgency is real but the effort is low, and the destinations are stable. Each path below opens to a full cost model, a phase-by-phase plan, and an in-depth guide for that specific move.