OCVS Consolidation Ratios: How to Model 2:1, 4:1 and 6–8:1 Safely

Overview

CPU consolidation ratio is one of the most misunderstood aspects of Oracle Cloud VMware Solution (OCVS) sizing.

Oversubscription is not a fixed number.

It is a workload-class-driven architectural decision balancing:

• Performance
• Cost
• Resiliency
• Risk tolerance

This guide provides a practical framework for applying consolidation ratios safely in enterprise OCVS environments.

Recommended Baseline Ratios

Consolidation ratio must be driven by workload class — never globally applied.

Mission Critical → 2:1

Use for:

• Databases
• ERP systems
• Financial platforms
• Latency-sensitive workloads
• Systems with strict SLAs

Why:

• Lower CPU Ready %
• Predictable performance
• Stable NUMA alignment
• Better host-failure tolerance

General Production Workloads → 4:1

Use for:

• Application servers
• APIs
• Middleware
• Business platforms

This is the enterprise “sweet spot” for OCVS.

It provides:

• Strong consolidation efficiency
• Controlled CPU Ready levels
• Good balance of cost vs performance

Most production estates should model around 4:1.

Dev/Test → 6:1 – 8:1

Use for:

• Development environments
• QA
• Lab workloads
• Bursty systems

Characteristics:

• High idle time
• No strict SLA
• Acceptable performance variability

However:

Never apply 8:1 blindly.

Always validate against peak utilization windows.

Oversubscription Is Not a Target

Consolidation ratios are not goals.

They are economic tuning levers.

Sizing must always be validated against:

• CPU Ready %
• Co-Stop %
• NUMA boundaries
• Host failure scenarios (N+1)

If CPU Ready exceeds 5–7% consistently, ratio is too aggressive.

Failure-State Modeling (Often Ignored)

The most common mistake in OCVS sizing is modeling ratio only in steady-state.

But clusters must survive host failure.

Example:

4-node cluster
Modeled at 4:1 consolidation

If one node fails:

Capacity drops by 25%.

Effective ratio increases:

4:1 → ~5.3:1

This may push CPU Ready into unsafe territory.

Therefore:

Consolidation must be modeled in failure-state, not only steady-state.

Excel Modeling Formula

In sizing worksheets: