VPS with Oracle Linux

Oracle Linux is Oracle Corporation's distribution, compatible with Red Hat Enterprise Linux. It is released almost at the same time as the corresponding RHEL versions, works with the same RPM packages and dnf commands, and is distributed free of charge: you can download the image, install the system and receive updates without a subscription. Only Oracle's technical support is paid. Oracle Linux appears in host templates noticeably less often than AlmaLinux and Rocky Linux, and people usually choose it for a specific reason: Oracle's own software.

Who needs Oracle Linux on a VPS

• For Oracle Database and related products. Oracle certifies its databases, WebLogic and development tools primarily on its own system, and the preinstall packages set the kernel parameters, limits and users the database installer requires in a single step.
• For test environments and learning. The free Oracle Database Free edition is designed for development and small projects and is officially supported on Oracle Linux 8 and 9, so a VPS with this system is handy for a training or test setup.
• Teams that already use Oracle Linux on their servers and want the same system on rented machines.
• Anyone moving off CentOS: Oracle released the centos2ol script for in-place migration. An overview of other replacement options is on the VPS with CentOS page.

For an ordinary website or a server under a panel there is almost no difference from other RHEL clones, but panels and host guides more often target AlmaLinux and Rocky Linux, and panel support for Oracle Linux can be incomplete, so check the panel developer's list of compatible systems before ordering.

Two kernels: UEK and RHCK

The main technical difference of Oracle Linux is the choice of kernel. By default the system boots the Unbreakable Enterprise Kernel (UEK): Oracle's kernel on a newer base, with its own improvements for databases, file systems and virtualisation. Alongside it you can install the Red Hat Compatible Kernel (RHCK), which is identical in compatibility to the RHEL kernel. RHCK is chosen when a third-party driver or monitoring agent is certified only for the RHEL kernel. You switch between them with grubby, and a reboot is needed after the change.

On a VPS this matters for two reasons. First, a host's template may boot either kernel by default: check uname -r, as the UEK kernel name contains "uek". Second, you can only choose the kernel on KVM: in OpenVZ and LXC containers the kernel is shared across the host's whole node, and neither UEK nor RHCK will be there.

Another Oracle feature is Ksplice: applying fixes to the kernel and key libraries without a reboot. It is part of paid support, so an ordinary rented VPS usually doesn't have it, and you still need to reboot the server after a kernel update. That's not a problem for a test environment, but for a database under constant load it's worth choosing a maintenance window in advance.

Versions and support periods

Oracle supports each major version for about ten years: Oracle Linux 8 until 2029, Oracle Linux 9 until 2032. For a new server it makes sense to go with version 9 if your software supports it. The 10 branch is newer, but not every host has a template for it, and its CPU requirements are higher than those of earlier versions, so check which CPU model the guest system sees before installing it on an older plan.

Resources, licences and what to check in a plan

The system itself is undemanding: a minimal install runs on 1 GB of memory and a 20 GB disk. The requirements are set by what you run on it. Oracle Database Free is comfortable from 4 GB of memory, 2 cores and 40 GB of fast disk; a full database needs more, and selections for such workloads are on the VPS for databases page.

A word on licences. Oracle Linux is free, but that doesn't apply to commercial editions of Oracle Database and other paid Oracle software. The rules for licensing them on virtual machines on third-party platforms differ from those for physical servers, so before installing a paid edition on a rented VPS, check the terms with Oracle or one of its partners. For test environments and learning, the free edition usually settles the question.

• Check which major version is in the template: cat /etc/oracle-release.
• If there is no template, on KVM the system is installed from the official image via custom ISO upload.
• Make sure the yum.oracle.com repositories are reachable from the server: without them, updates won't arrive.