Azure Linux (CBL-Mariner)

Basic Information

• Model: Microsoft Azure Linux, formerly known as CBL-Mariner (Common Base Linux Mariner), is a lightweight Linux distribution developed by Microsoft. It serves as an internal Linux distribution for Microsoft's cloud infrastructure and edge products and services.
• Version: The latest stable version is 3.0.20250102, released on January 2, 2025. Updates are released regularly, with the first update of 2024 released on January 15, 2024.
• Release Date: Initial release as CBL-Mariner was April 1, 2020. It was made publicly available in July 2021.
• Minimum Requirements: For testing and basic workloads, 1 vCPU, 0.5GB to 2GB of RAM, and 8GB to 16GB of disk storage are sufficient.
• Supported Operating Systems: Not applicable, as it is an operating system.
• Latest Stable Version: 3.0.20250102.
• End of Support Date: Not explicitly stated in public documentation, but Microsoft provides continuous updates and security patches.
• End of Life Date: Not explicitly stated.
• Auto-update Expiration Date: Not explicitly stated, but it supports both package-based and image-based update models for continuous servicing.
• License Type: Primarily MIT License, with some components under Photon License, Apache License v2, GPLv2, and LGPLv2.1.
• Deployment Model: Designed for cloud infrastructure and edge products and services, including Azure services, Azure Kubernetes Service (AKS), Azure Stack HCI, Azure IoT Edge, and as a base container OS. It can be deployed as a container or a virtual machine.

Technical Requirements

• RAM: Minimum 0.5GB to 2GB for basic testing.
• Processor: 1 vCPU for basic testing.
• Storage: 8GB to 16GB disk storage for basic testing.
• Display: No graphical user interface (GUI) by default; it is a server-side Linux.
• Ports: Specific port requirements depend on the services deployed on the OS.
• Operating System: Not applicable.

Analysis of Technical Requirements: Azure Linux is designed to be lightweight and minimalist, requiring modest hardware resources. This lean design contributes to faster boot times and a reduced attack surface, making it suitable for cloud and edge environments where efficiency and security are paramount. The absence of a GUI further emphasizes its role as a backend or container host OS.

Support & Compatibility

• Latest Version: 3.0.20250102.
• OS Support: Not applicable, as it is an operating system.
• End of Support Date: Continuous updates and security patches are provided.
• Localization: Not explicitly detailed, but as a base OS for cloud services, localization is typically handled at the application layer.
• Available Drivers: Includes support for various hardware, such as Intel SGX drivers for secure computing and AMDGPU kernel graphics drivers. It also includes drivers for Dell devices and NVMe multi-path support.

Analysis of Overall Support & Compatibility Status: Azure Linux is actively maintained by Microsoft, with regular updates and security patches. Its compatibility extends to various Azure services, including AKS, Azure Stack HCI, and Azure IoT Edge. The inclusion of specific hardware drivers like Intel SGX and AMDGPU indicates support for specialized workloads and evolving hardware ecosystems. It is built and tested by Azure Edge & Platform, ensuring compatibility with Azure agents and validation tests.

Security Status

• Security Features: Follows a secure-by-default principle. Features include a hardened kernel, signed updates, Address Space Layout Randomization (ASLR), compiler-based hardening, and tamper-resistant logs. It also supports SYN cookies for networking.
• Known Vulnerabilities: Microsoft provides fast turnaround times for security patches and fixes. Azure Linux offers its own security advisories, which are used for vulnerability scanning.
• Blacklist Status: Not applicable.
• Certifications: Not explicitly detailed, but it undergoes Azure validation tests.
• Encryption Support: Supports Intel SGX (Software Guard Extensions) for secure computing, including encryption.
• Authentication Methods: Standard Linux authentication methods are supported.
• General Recommendations: Microsoft recommends building custom images with only required packages for enhanced security. It is also recommended to keep the OS updated.

Analysis on the Overall Security Rating: Azure Linux prioritizes security through its minimalist design, reducing the attack surface. Its secure-by-default approach, coupled with features like a hardened kernel and signed updates, provides a robust security posture. Microsoft's commitment to rapid patching and its own security advisories further strengthen its security. The support for Intel SGX indicates a focus on confidential computing.

Performance & Benchmarks

• Benchmark Scores: Specific benchmark scores are not widely published for direct comparison.
• Real-world Performance Metrics: Known for fast boot times and consuming limited disk and memory resources due to its lightweight nature. It is designed for efficiency in cloud and edge environments.
• Power Consumption: Its lightweight design suggests lower power consumption compared to more feature-rich distributions.
• Carbon Footprint: Not explicitly measured, but reduced resource consumption generally correlates with a lower carbon footprint.
• Comparison with Similar Assets: Positioned as a contender to minimalist, cloud-ready Linux distributions like Red Hat's Fedora CoreOS, RancherOS, and Ubuntu Core. It is designed to provide a consistent platform for Microsoft's cloud infrastructure and edge products, similar to how Amazon Linux serves AWS.

Analysis of the Overall Performance Status: Azure Linux excels in performance due to its minimalist design, which translates to faster boot times and efficient resource utilization. Its focus on core functionalities for cloud and edge services ensures optimal performance for its intended use cases. While direct benchmark comparisons are limited, its architectural choices align with high-performance, low-overhead operations.

User Reviews & Feedback

• Strengths: Users praise its stability, security, and lightweight nature. It offers fast boot times and a minimal attack surface. Its RPM-based package system and image-based update mechanism are also noted. It is considered rock-solid in production environments.
• Weaknesses: Not intended as a general-purpose desktop Linux distribution. Building custom images can be complex for those without Linux expertise. It uses tdnf instead of apt, which can be a difference for users accustomed to Debian-based systems.
• Recommended Use Cases: Ideal for Microsoft's cloud infrastructure, edge products and services, Azure Kubernetes Service (AKS) container hosts, Azure IoT Edge, and as a base container image. It is suitable for container-first applications and lightweight cloud services.

Summary

Microsoft Azure Linux, formerly CBL-Mariner, is a purpose-built, lightweight Linux distribution designed for Microsoft's cloud and edge computing environments. Its core strength lies in its minimalist design, which ensures high performance, fast boot times, and a significantly reduced attack surface. The OS adheres to a secure-by-default principle, incorporating features like a hardened kernel, signed updates, and ASLR, making it a robust choice for security-sensitive deployments. Microsoft actively maintains and updates Azure Linux, providing continuous security patches and support for specialized hardware.

While highly effective for its intended use cases—such as container hosts in Azure Kubernetes Service, Azure IoT Edge, and other Azure services—it is not a general-purpose desktop operating system. Its primary deployment model involves building custom images tailored to specific workloads, which might present a learning curve for some users. However, for enterprise asset management within Microsoft's ecosystem, Azure Linux offers a stable, secure, and efficient platform for critical cloud and edge infrastructure. Its focus on essential components and rapid update cycles makes it a reliable foundation for modern cloud-native applications.

The information provided is based on publicly available data and may vary depending on specific device configurations. For up-to-date information, please consult official manufacturer resources.