Selecting the correct virtual machine size is one of the most important architectural decisions when deploying enterprise workloads in the public cloud. On Microsoft Azure, the wide range of VM families allows architects to fine-tune performance, scalability, and cost efficiency, but it also introduces complexity. When running Red Hat Enterprise Linux 8 on Microsoft Azure, the choice of VM family directly affects how applications behave under load, how predictable performance remains over time, and how well costs are controlled.
This technical article provides a detailed, practical guide to choosing the right Azure VM family for RHEL workloads. It explains how Red Hat Enterprise Linux 8 interacts with Azure’s hypervisor and hardware stack, analyzes the main VM families available today, and maps real-world workload patterns to the most suitable VM types. The goal is to help you make informed, production-grade decisions for stable and scalable Linux deployments.
Understanding RHEL 8 on Microsoft Azure
Red Hat Enterprise Linux 8 is built for enterprise environments where stability, long-term support, and predictable performance are essential. From a cloud perspective, RHEL 8 integrates tightly with Azure through:
- Optimized kernels tested for Azure Hyper-V
- Native support for Azure Linux Agent and cloud-init
- Enhanced networking via Accelerated Networking (SR-IOV)
- Mature support for Azure managed disks and storage tiers
Azure runs RHEL 8 on a highly optimized virtualization stack that minimizes overhead and enables near bare-metal performance. However, the VM family you choose determines how CPU, memory, disk bandwidth, and network throughput are allocated to the operating system.
Core Criteria for Selecting an Azure VM Family
Before evaluating individual VM families, it is essential to understand the main dimensions that influence performance on Red Hat Enterprise Linux 8.
Compute Characteristics
Some workloads depend on high clock speeds and low latency, while others require many cores for parallel processing. RHEL 8 performs well in both scenarios, but VM family selection determines whether you prioritize single-thread or multi-thread performance.
Memory Requirements
Applications such as databases, application servers, and in-memory caches depend heavily on available RAM. Insufficient memory leads to swapping and performance degradation, even if CPU resources are plentiful.
Storage Throughput and IOPS
Disk-intensive workloads rely on predictable throughput and low latency. Azure VM families differ in how much disk bandwidth and IOPS they can sustain, especially when using Premium or Ultra disks.
Networking Performance
Microservices, distributed systems, and clustered applications benefit from low-latency, high-throughput networking. Some Azure VM families offer significantly higher network performance.
Cost and Scalability
Overprovisioning increases costs, while underprovisioning creates bottlenecks. Right-sizing VM families for RHEL 8 workloads is key to long-term efficiency.
General Purpose VM Families (B and D Series)
B Series: Burstable Workloads
The B series is designed for workloads with variable CPU usage and long idle periods.
Best use cases on RHEL 8:
- Development and testing environments
- Small internal services
- Low-traffic applications
Advantages:
- Cost-effective for intermittent workloads
- Simple scaling for non-critical systems
Limitations:
- CPU throttling under sustained load
- Not suitable for production systems with constant demand
Red Hat Enterprise Linux 8 runs reliably on B-series VMs, but these instances should be used carefully in production environments.
D Series: Balanced Performance
The D series is one of the most widely used VM families on Azure and is often the default choice for RHEL deployments.
Best use cases:
- Enterprise application servers
- Small to medium databases
- General-purpose workloads
Advantages:
- Balanced CPU and memory ratio
- Strong disk and network performance
- Broad availability across regions
For many workloads, D-series VMs provide an excellent foundation for running Red Hat Enterprise Linux 8 in production.
Compute Optimized VM Families (F Series)
The F series is designed for workloads that demand high CPU performance with relatively modest memory requirements.
Best use cases on RHEL 8:
- High-performance web servers
- Batch processing jobs
- Scientific and engineering workloads
Advantages:
- High clock speeds
- Excellent price-to-performance for CPU-bound tasks
Considerations:
- Lower memory per vCPU
- Not ideal for memory-intensive applications
Thanks to its modern kernel and scheduler, RHEL 8 performs efficiently on F-series VMs, especially for stateless and horizontally scalable services.
Memory Optimized VM Families (E and M Series)
E Series: High Memory-to-Core Ratio
The E series is optimized for memory-intensive workloads.
Best use cases:
- Relational databases
- JVM-based enterprise applications
- In-memory analytics
Advantages:
- Reduced memory pressure
- Improved performance for cache-heavy workloads
Red Hat Enterprise Linux 8 benefits significantly from E-series VMs due to improved page caching and reduced swap activity.
M Series: Large-Scale Memory
M-series VMs are designed for extremely memory-heavy workloads.
Best use cases:
- Large enterprise databases
- In-memory analytics platforms
- Mission-critical workloads with high RAM demands
These instances are typically chosen when memory requirements exceed what E-series VMs can provide.
Storage Optimized VM Families (L Series)
The L series is optimized for storage throughput and local disk capacity.
Best use cases on RHEL 8:
- Log ingestion and processing
- Data warehousing
- Distributed storage systems
Advantages:
- High disk throughput
- Large local SSD capacity
Trade-offs:
- Lower CPU-to-storage balance for compute-heavy workloads
When tuned correctly, RHEL 8 can efficiently handle large-scale storage workloads on L-series VMs.
High-Performance and HPC VM Families (H Series)
The H series is designed for high-performance computing workloads.
Best use cases:
- Computational fluid dynamics
- Financial risk modeling
- Large-scale simulations
Advantages:
- High core counts
- Low-latency interconnects
- Optimized for parallel workloads
Red Hat Enterprise Linux 8 is well-suited for HPC scenarios due to its mature NUMA handling and support for advanced scheduling features.
Matching Azure VM Families to Common Workloads
Web and Application Servers
D-series VMs are often the best starting point. For CPU-heavy web services, F-series VMs may provide better efficiency.
Databases
Memory is critical. E-series VMs work well for most databases, while M-series VMs are suitable for very large datasets.
CI/CD and DevOps Pipelines
F-series or D-series VMs provide strong performance for builds and automated testing. B-series VMs may suffice for lightweight pipelines.
Analytics and Data Processing
Choose between E-series and L-series depending on whether the workload is memory-bound or disk-bound.
Performance Tuning on RHEL 8 in Azure
Regardless of VM family, tuning is essential to get the best results from Red Hat Enterprise Linux 8:
- Enable Accelerated Networking where supported
- Optimize disk caching modes for your workload
- Adjust kernel parameters for memory and I/O behavior
- Monitor CPU steal time and I/O latency
Azure-native monitoring tools combined with RHEL performance utilities provide deep visibility into system behavior.
Cost Optimization and Right-Sizing Strategies
Choosing the correct VM family is only the first step. Continuous monitoring and periodic resizing help ensure workloads remain efficient. Azure Reserved Instances and Savings Plans can significantly reduce costs for predictable RHEL 8 workloads, while autoscaling helps manage variable demand.
Conclusion
Choosing the right Azure VM family for RHEL 8 is a strategic decision that directly affects performance, stability, and cost. By understanding workload characteristics and aligning them with the appropriate VM family, organizations can fully leverage Red Hat Enterprise Linux 8 on Microsoft Azure. With the right balance of compute, memory, storage, and networking, Azure provides a robust platform for running enterprise-grade Linux workloads at scale.
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