CoreOS vs Red Hat Enterprise Linux: What are the differences?

CoreOS and Red Hat Enterprise Linux (RHEL) are two widely used operating systems with distinct differences in terms of architecture, features, and target use cases. Here are the key differences between the two:

1. Container Focus: CoreOS is specifically designed to provide an optimal environment for containerized applications. It includes features like automatic updates, container runtime, and support for various container orchestration platforms such as Kubernetes and Docker Swarm. On the other hand, while RHEL also supports containerization, it is a more general-purpose operating system catering to a wide range of enterprise computing needs beyond containers.

2. Atomic Update Model: CoreOS employs an atomic update model, where the entire operating system is updated as a single unit. This ensures that updates are consistent and can be rolled back or tested easily. In contrast, RHEL follows a traditional update model where packages are individually updated, which may not provide the same level of predictability and ease of management.

3. Security and Hardening: CoreOS puts a strong emphasis on security and includes features like read-only file system, automatic updates, and built-in cryptographic verification of the system. It also has a smaller attack surface due to its minimalistic design. RHEL, being an enterprise-grade operating system, also incorporates security features but may offer additional security certifications and compliance validations required by specific industries or regulations.

4. Support and Stability: RHEL is known for its long-term support and stability, making it a trusted choice for enterprise deployments in critical infrastructures. It offers extended support life cycles, regular updates, and access to Red Hat's technical support and professional services. CoreOS, on the other hand, provides a lighter-weight option with more frequent updates, catering to organizations that value rapid innovation and do not require the same level of long-term stability.

5. Pricing and Licensing: RHEL is a commercially licensed operating system with subscription-based pricing, providing customers access to technical support, updates, and a wide range of enterprise features. CoreOS, on the other hand, is available as an open-source project with a permissive license and offers a free-to-use version called CoreOS Container Linux. However, additional services and features, such as CoreOS Quay for application registry, may have separate pricing models.

6. Ecosystem and Integration: RHEL has a mature ecosystem and extensive compatibility with various enterprise software solutions and hardware platforms. It is often a preferred choice for running traditional enterprise applications, databases, and middleware. CoreOS, on the other hand, has a more focused ecosystem with integration primarily aimed at container-centric technologies. It works well within container orchestration platforms and is optimized for running cloud-native applications.

In summary, CoreOS is specifically designed for container-centric environments, offering features like automatic updates, atomic updates, and strong security focus. On the other hand, RHEL provides a broader range of enterprise computing capabilities, certified security features, long-term support, and a mature ecosystem.