9th  March, 2024  

Mixed-Shape Clusters for Oracle Cloud VMware Solution

Introduction

Oracle Cloud VMware Solution (OCVS) continues to evolve, providing greater flexibility and resource optimization for VMware deployments. One of the latest features introduced is mixed-shape clusters, which allow you to combine different compute shapes within the same processor family. In this comprehensive guide, we’ll delve into the technical details of mixed-shape clusters, their benefits, and considerations for implementation.

What Are Mixed-Shape Clusters?

Mixed-shape clusters provide a powerful way to tailor your compute resources to the specific workload requirements within your VMware environment. Here’s a closer look at what they offer:

1. Flexibility: With mixed-shape clusters, you can seamlessly blend and match host shapes of varying core counts. This flexibility allows you to adapt to the ever-changing computational demands of your workloads.

2. Seamless Hardware Transitions: As Oracle Cloud introduces newer Compute shapes, you can integrate them into your existing mixed-shape clusters without disrupting operations. Familiar VMware tools like vMotion and Enhanced vMotion Compatibility (EVC) make workload migration to the latest hardware effortless.

3. Streamlined Management: Building upon the multicluster SDDC (software-defined data center) concept, mixed-shape clusters are managed as a unified entity. This approach significantly reduces management overhead and simplifies day-to-day operations.

Activation and Considerations

Before diving into mixed-shape clusters, consider the following points:

1. Day 2 Operations: Mixed-shape clusters are part of the Day 2 operations within your SDDC. While activating this feature is straightforward in the Oracle Cloud Console, understanding its implications is crucial.

2. Homogeneous vs. Heterogeneous Clusters: VMware generally recommends utilizing homogeneous clusters composed of identical Compute shapes with matching OCPU (Oracle Compute Unit). However, mixed-shape clusters provide an alternative when workload diversity demands it.

3. Resource Optimization: Evaluate your workload requirements carefully. Mixed-shape clusters allow you to optimize resources by aligning compute shapes precisely, but improper planning could lead to inefficiencies.

Additional Considerations

In addition to the points mentioned earlier, here are further considerations for implementing mixed-shape clusters:

4. Workload Requirements: Thoroughly assess your workload resource requirements to determine the ideal combination of compute shapes. Understand the specific demands of your applications and allocate resources accordingly.

5. Processor Family Compatibility: Mixed-shape clusters are limited to the same processor family. All hosts within the cluster must be either Intel-based or AMD-based. Ensure compatibility when adding new hosts.

6. ESXi Host Shape Eligibility: The ability to add a specific shape to a mixed-shape cluster depends on the initial host shape used to create the cluster. Refer to the compatibility table below for eligible shapes:

Note: The BM.GPU.A10.4 shape is currently in limited availability and supported only with VMware Software version 7 update 3.

7. ESXi Software Version: Mixed-shape clusters support the addition of hosts running any available ESXi software version for Oracle Cloud VMware Solution, provided it matches the SDDC’s major VMware software version. You can select the minor version during host addition.

8. Maximum Hosts Limitation: Be aware that mixed-shape clusters have a maximum limit on the number of hosts. Ensure you stay within the allowed range for optimal performance.

9. vMotion Compatibility: vMotion requires all ESXi hosts within a cluster to have the same CPU family. EVC (Enhanced vMotion Compatibility) addresses this challenge by establishing a baseline set based on the least advanced processor configuration supported by all ESXi hosts in the cluster.

 Conclusion:
Mixed-shape clusters represent a significant leap forward for the Oracle Cloud VMware Solution ecosystem. They unlock a new level of flexibility, enabling seamless hardware transitions and precise resource alignment with workload demands. By carefully considering workload requirements and potential limitations, you can leverage mixed-shape clusters to harness the unmatched flexibility, resource optimization, and simplified management offered by Oracle Cloud VMware Solution.