Introduction
Microsoft Azure has established itself as a leading cloud platform for enterprises running mission-critical workloads, hybrid architectures, and globally distributed applications. As organizations migrate from on-premises infrastructure to the cloud, one of the most important design decisions is the choice of operating system used as the foundation for virtual machines. For enterprises that prioritize stability, long-term support, security certifications, and vendor-backed lifecycle guarantees, Red Hat Enterprise Linux (RHEL) remains one of the most trusted Linux platforms available.
On Azure, RHEL is delivered through officially supported virtual machine images published in Microsoft Azure Marketplace. These images are curated, tested, and maintained in close collaboration between Microsoft and Red Hat, ensuring compatibility with Azure infrastructure, services, and compliance frameworks. Among the available versions, RHEL 9 represents a modern enterprise Linux platform designed for cloud-native workloads, automation, and zero-trust security models.
In the middle of evaluating available Linux distributions on Azure, many architects and administrators come across the concept of a Red Hat Enterprise Linux 9 image, which refers to a Marketplace-published RHEL 9 virtual machine image that is optimized, licensed, and supported for Microsoft Azure environments. Understanding what these images include, how they are licensed, and how they integrate with Azure services is essential for building reliable and compliant cloud solutions.
This article provides a detailed technical overview of RHEL 9 images in Microsoft Azure Marketplace, covering image architecture, licensing models, security features, performance optimizations, update mechanisms, and real-world enterprise use cases.
What Is an Azure Marketplace Image?
An Azure Marketplace image is a preconfigured virtual hard disk (VHD) packaged with metadata that defines how a virtual machine is created and deployed in Azure. Marketplace images typically include:
- A preinstalled operating system
- Azure-specific agents and integrations
- Licensing and billing configuration
- Regional availability and versioning
When a virtual machine is launched from Azure Marketplace, Azure provisions the OS disk from the image and applies user-defined parameters such as VM size, networking, storage, and identity.
RHEL 9 images in Azure Marketplace are official Red Hat images, validated and maintained to meet both Red Hat and Microsoft standards.
Overview of Red Hat Enterprise Linux 9
Red Hat Enterprise Linux 9 is designed to support modern enterprise workloads across hybrid and multi-cloud environments. It emphasizes security-by-default, predictable lifecycle management, and compatibility with modern development tools.
Key characteristics of RHEL 9 include:
- A long-term lifecycle with up to 10 years of support
- Modern kernel and userland components
- Strong ABI and API stability guarantees
- Enhanced automation and management tooling
- Tight integration with container platforms and DevOps workflows
RHEL 9 is engineered to provide consistency across on-premises data centers, private clouds, and public cloud platforms like Microsoft Azure.
RHEL 9 Images in Microsoft Azure Marketplace Explained
RHEL 9 images published in Azure Marketplace are purpose-built cloud images rather than generic OS installations. They are optimized specifically for Azure’s virtualization stack and management model.
Core Characteristics
- Azure-optimized kernel and drivers
- Azure Linux Agent (waagent) preinstalled
- Cloud-init support for provisioning and automation
- Gen2 VM compatibility with UEFI and Secure Boot
- Pay-as-you-go licensing integrated with Azure billing
These features ensure that RHEL 9 virtual machines behave predictably and integrate seamlessly with Azure services from the first boot.
Licensing and Subscription Models on Azure
One of the most important aspects of using RHEL on Azure is understanding licensing.
Pay-As-You-Go (PAYG)
Most RHEL 9 images in Azure Marketplace use a consumption-based licensing model:
- The Red Hat subscription cost is included in the VM hourly rate
- No separate subscription registration is required
- Ideal for dynamic, elastic, and short-lived workloads
Azure Hybrid Benefit for Linux
For organizations with existing Red Hat subscriptions, Azure also supports bring-your-own-subscription (BYOS) models using Azure Hybrid Benefit for Linux. This allows customers to:
- Apply existing RHEL entitlements to Azure VMs
- Reduce operational costs
- Maintain centralized subscription management
Update Infrastructure and Package Management
RHEL 9 images on Azure are integrated with Red Hat Update Infrastructure (RHUI), hosted jointly by Microsoft and Red Hat.
Benefits of RHUI
- No need to register systems individually
- Automatic access to security updates and bug fixes
- High availability and scalability for package repositories
Administrators can use standard tools such as dnf to manage updates, install packages, and perform minor version upgrades.
Security Features in RHEL 9 Azure Images
Security is a foundational pillar of RHEL 9, making it well-suited for regulated and security-sensitive workloads.
SELinux Enforcing by Default
Security-Enhanced Linux (SELinux) is enabled and enforcing out of the box, providing mandatory access control policies that significantly limit the impact of compromised services.
System-Wide Cryptographic Policies
RHEL 9 introduces centralized cryptographic policies, enabling consistent enforcement of:
- Strong encryption algorithms
- Approved TLS versions
- Compliance-ready cryptographic standards
These policies simplify alignment with internal security baselines and regulatory requirements.
Secure Boot and Trusted Launch
RHEL 9 images support Azure Gen2 virtual machines with Secure Boot enabled, helping protect against boot-level malware and unauthorized kernel modifications.
Performance Optimization for Azure
RHEL 9 images are tuned to take full advantage of Azure’s infrastructure.
Storage and Networking
- Optimized drivers for Azure managed disks
- Support for Premium SSD, Ultra Disk, and ephemeral OS disks
- Accelerated Networking support for low latency and high throughput
CPU Architecture Support
RHEL 9 images are available for multiple architectures, including:
- x86_64 for Intel and AMD-based VM sizes
- ARM64 for Azure ARM-based instances
This flexibility allows organizations to optimize for cost, performance, or power efficiency.
Tuned Profiles
The tuned service dynamically adjusts system parameters based on workload type, improving performance for compute-intensive, I/O-heavy, or latency-sensitive applications.
Cloud-Init and Automation on Azure
Automation is a core requirement for modern cloud operations, and RHEL 9 images on Azure fully support cloud-init.
Common Cloud-Init Use Cases
- SSH key injection
- User and group configuration
- Package installation at first boot
- Execution of custom scripts
- Integration with configuration management tools
This makes RHEL 9 images ideal for Infrastructure as Code (IaC) approaches using tools such as ARM templates, Bicep, or Terraform.
Lifecycle and Version Management
RHEL 9 follows a predictable and enterprise-friendly lifecycle.
Minor Release Stability
- Regular minor releases with new features and enhancements
- No breaking changes to core system interfaces
- Safe in-place upgrades supported
Long-Term Support
The extended lifecycle of RHEL 9 makes it suitable for workloads that must remain stable for many years, such as enterprise applications, regulated systems, and critical infrastructure.
Compliance and Regulatory Readiness
RHEL 9 is widely adopted in industries with strict compliance requirements.
Common compliance alignments include:
- FIPS 140-2 and 140-3 readiness
- Common Criteria certifications
- DISA STIG guidance
- Foundations for HIPAA, PCI-DSS, and ISO standards
When deployed on Microsoft Azure, these compliance features integrate with Azure-native security and governance tools such as Azure Policy and Microsoft Defender for Cloud.
Common Use Cases for RHEL 9 on Azure
RHEL 9 images in Azure Marketplace support a wide range of enterprise workloads.
Enterprise Applications
- Business-critical middleware
- ERP and line-of-business applications
- Java and application servers
Cloud-Native and Container Platforms
- Kubernetes worker nodes
- OpenShift-compatible environments
- Microservices-based architectures
Data and Analytics
- Relational and NoSQL databases
- Data processing and ETL pipelines
- AI and machine learning workloads
DevOps and Automation
- CI/CD build agents
- Configuration management servers
- Infrastructure automation nodes
Best Practices for Using RHEL 9 Images on Azure
To maximize reliability and security, consider these best practices:
- Always deploy the latest Marketplace image version
- Use managed identities instead of embedded credentials
- Enable automatic security updates where appropriate
- Integrate monitoring with Azure Monitor and Log Analytics
- Harden SSH access and disable password authentication
Conclusion
RHEL 9 images in Microsoft Azure Marketplace provide a powerful, secure, and enterprise-grade foundation for running Linux workloads in the cloud. By combining Red Hat’s proven enterprise Linux platform with Azure-native integrations, these images simplify deployment while meeting the demands of modern hybrid and cloud-native architectures.
With strong security defaults, predictable lifecycle management, seamless automation support, and deep integration with Azure services, RHEL 9 images enable organizations to build scalable, compliant, and future-ready solutions on Microsoft Azure with confidence.