Rocky Linux 9: the Complete Guide for Your Server

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Why Rocky Linux 9 became the go-to OS to replace CentOS: RHEL compatibility, support until 2032, migration paths and first steps on a VPS.

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Rocky Linux 9 is a free, open-source enterprise Linux distribution, bug-for-bug compatible with Red Hat Enterprise Linux 9. Created by Gregory Kurtzer (co-founder of the original CentOS project) after Red Hat discontinued classic CentOS, it is governed by the Rocky Enterprise Software Foundation (RESF) and has become the default choice for servers that used to run CentOS.

In practice: everything that runs on RHEL 9 runs on Rocky 9 — RPM packages, SELinux, dnf, panels like Plesk or cPanel — with no license to pay and security updates guaranteed until May 2032.

Where does Rocky Linux come from?

For 15 years, CentOS was the most used free RHEL clone on servers. In late 2020, Red Hat turned CentOS into CentOS Stream, an "upstream" version of RHEL that is less stable by design. In response, the community launched two faithful successors: Rocky Linux and AlmaLinux. Rocky — named after the late CentOS co-founder Rocky McGaugh — rebuilds every RHEL release identically.

Rocky Linux 9 in numbers

  • Base: 1:1 rebuild of Red Hat Enterprise Linux 9
  • Kernel: Linux 5.14 (with security backports from Red Hat)
  • Support: security updates until May 31, 2032 — a 10-year lifecycle
  • Package manager: dnf, BaseOS / AppStream repos + EPEL for extras
  • Security: SELinux enforcing by default, firewalld, OpenSSL 3.0
  • Minor releases: 9.x roughly every 6 months, seamless upgrade via dnf

Why pick it for a server?

  • Enterprise stability: package versions are frozen and patched for 10 years — no surprise update breaking production
  • RHEL compatibility: RHEL documentation, tutorials and certified software apply as-is
  • Hosting panels: Plesk and cPanel officially support Rocky 9
  • Free forever: the RESF guarantees no license will ever be required

Migrating from CentOS 7

CentOS 7 has been end-of-life since June 30, 2024: no security updates at all. If you still run CentOS 7 servers, migration is urgent. Two paths: in-place migration with the ELevate tool (CentOS 7 → Alma/Rocky 8 → 9, always test outside production), or — what we recommend on a VPS — a clean reinstall: deploy a fresh Rocky 9 VPS, reinstall your services, migrate the data (rsync, SQL dumps), switch the DNS. It is more predictable and you start from a healthy system.

Getting started on a Rocky 9 VPS

At By-Hoster, the Rocky Linux 9 image is available when deploying any KVM VPS: server delivered in 60 seconds. First steps after connecting via SSH:

  • dnf update -y — apply all updates
  • Create a sudo user and disable root SSH password login (use SSH keys)
  • firewall-cmd — only open the ports you need (80/443, your SSH port)
  • dnf install epel-release — enable the EPEL repo for fail2ban and common tools
  • Keep SELinux enforcing: it is protection — learn to use it rather than disable it

Frequently asked questions

Yes, 100%. Rocky Linux is developed by the RESF, whose bylaws guarantee the distribution will remain free. You only pay for the infrastructure that hosts it.

Both are excellent, stable CentOS successors. Rocky aims for a 1:1 RHEL rebuild; Alma allows slight divergence (ABI compatibility). In practice, for a web server or VPS it mostly comes down to preference — both are available on our VPS.

Until May 31, 2032 for security updates. Rocky Linux 10 is already available to take over beyond that — but no rush: 9 remains the safe choice for production.

No — strongly discouraged: no vulnerability has been patched since June 2024. An Internet-facing CentOS 7 server is a target. Migrate to Rocky 9 (or Alma 9) as soon as possible.

A question of ecosystem: Rocky if you come from the RHEL/CentOS world (SELinux, dnf, 10-year cycle, RHEL-certified software), Debian if you prefer apt and its huge package library. Both are excellent server choices, available on our VPS.

See also