Dedicated Instances are Amazon EC2 instances that run on hardware that is allocated to a single AWS customer. This means your instances are physically isolated at the host hardware level from instances belonging to other AWS accounts, providing an additional layer of isolation for your workloads.
…Dedicated Instances are Amazon EC2 instances that run on hardware that is allocated to a single AWS customer. This means your instances are physically isolated at the host hardware level from instances belonging to other AWS accounts, providing an additional layer of isolation for your workloads.
Key characteristics of Dedicated Instances include:
1. **Hardware Isolation**: Your instances run on hardware that no other customer can access. This is particularly important for organizations with strict compliance requirements or security policies that mandate physical separation from other tenants.
2. **Pricing Model**: Dedicated Instances have a unique pricing structure. You pay a per-region fee of $2 per hour when at least one Dedicated Instance is running in that region, plus an hourly rate for each Dedicated Instance that varies by instance type. This makes them more expensive than standard On-Demand instances.
3. **Flexibility**: Unlike Dedicated Hosts, you do not have control over which specific physical server your instance runs on. AWS manages the underlying hardware placement, though it ensures your instances remain isolated from other customers.
4. **Use Cases**: Organizations in regulated industries such as healthcare, finance, and government often use Dedicated Instances to meet compliance requirements like HIPAA, PCI-DSS, or specific licensing agreements that require dedicated hardware.
5. **Comparison with Dedicated Hosts**: While both options provide hardware isolation, Dedicated Hosts give you visibility and control over the physical server, allowing you to use existing server-bound software licenses. Dedicated Instances offer isolation with less management overhead.
6. **Billing Considerations**: The per-region fee applies once per region regardless of how many Dedicated Instances you run, making costs more predictable when running multiple instances.
Dedicated Instances represent a middle ground between shared tenancy and full Dedicated Host control, offering compliance-friendly isolation while maintaining operational simplicity.
Dedicated Instances are Amazon EC2 instances that run on hardware that is dedicated to a single AWS account. Your Dedicated Instances are physically isolated at the host hardware level from instances that belong to other AWS accounts. This means the underlying physical server is not shared with other customers.
Why are Dedicated Instances Important?
Dedicated Instances are crucial for organizations that have:
• Compliance requirements - Some industries and regulations require physical isolation of computing resources • Licensing restrictions - Certain software licenses are tied to physical hardware or require dedicated tenancy • Security policies - Corporate policies may mandate that workloads run on single-tenant hardware • Sensitive workloads - Applications handling highly sensitive data may require physical separation
How Dedicated Instances Work
When you launch a Dedicated Instance:
1. AWS allocates the instance on hardware dedicated to your account 2. The physical host is not shared with instances from other AWS accounts 3. You may still share the host with other instances from your own account (unless using Dedicated Hosts) 4. When instances are stopped and restarted, they may move to different dedicated hardware 5. You pay a per-region fee plus an hourly per-instance fee
Dedicated Instances vs. Dedicated Hosts
Understanding the difference is critical for the exam:
• Dedicated Instances - You get dedicated hardware but have no visibility or control over the physical host • Dedicated Hosts - You get an entire physical server with visibility into sockets, cores, and host ID; useful for bring-your-own-license (BYOL) scenarios
Pricing Considerations
• Dedicated Instances cost more than shared tenancy instances • There is a dedicated per-region fee charged once per hour per region • Additional per-instance hourly charges apply • Available with On-Demand, Reserved Instance, and Spot pricing models
Exam Tips: Answering Questions on Dedicated Instances
Key points to remember:
1. Compliance and Isolation - When a question mentions regulatory compliance, physical isolation, or single-tenant requirements, Dedicated Instances or Dedicated Hosts are likely the answer
2. Know the Difference - If a question asks about visibility into physical servers or BYOL licensing that requires socket/core information, the answer is Dedicated Hosts, not Dedicated Instances
3. Cost Awareness - Questions about cost-effective solutions typically will not have Dedicated Instances as the answer since they are more expensive
4. Tenancy Settings - Remember that tenancy can be set at the VPC level (all instances in VPC become dedicated) or at the instance level
5. Common Exam Scenarios: - Company needs physical isolation = Dedicated Instances or Dedicated Hosts - Company needs to use existing server-bound licenses = Dedicated Hosts - Company wants cost optimization = Shared tenancy (default)
6. Watch for Distractors - Do not confuse Dedicated Instances with Reserved Instances (a pricing model) or with security groups (a network security feature)
Quick Reference Summary
• Purpose: Physical isolation from other AWS customers • Use case: Compliance, licensing, security requirements • Cost: Higher than shared tenancy • Control: Less than Dedicated Hosts, more isolation than default • Flexibility: Can move between dedicated hardware within your account