EBS IOPS: Are You Paying for Performance You Can't Use?

Here are 5 key takeaways from the episodes discussion on EBS performance optimization:

Understanding IOPS Misalignment

• EBS volumes can be provisioned with more IOPS than EC2 instances can support
• This leads to wasted resources and unnecessary costs
• Example: A c5.large instance can only support 20,000 IOPS, but an attached volume might be provisioned with 25,000 IOPS

Identifying the Problem

• Use AWS CLI to get instance type information:

aws ec2 describe-instance-types —query "InstanceTypes[*].[InstanceType,EbsInfo.MaximumIops]" —output json

• Utilize AWS Cost and Usage Reports (CUR) data in Athena queries to compare provisioned IOPS with instance limits

Impact on Performance and Cost

• Over-provisioned IOPS can't be utilized, leading to wasted spending
• In some cases, this misalignment can result in unexpected performance issues
• Cost impact can be significant: 5,000 unnecessary IOPS at $0.065 per IOPS/month adds up quickly

Solution Approaches

• Right-size EBS volumes to match EC2 instance capabilities
• Consider upgrading EC2 instances if higher IOPS are truly needed
• Implement regular audits to catch and correct misalignments

Best Practices

• Review default IOPS settings in infrastructure-as-code templates
• Consider adding guardrails to prevent IOPS over-provisioning (currently no built-in AWS feature for this)
• Leverage AWS Cost Optimization Hub for broader optimization recommendations
• This issue highlights the importance of aligning your EBS performance with your EC2 instances' capabilities. By addressing IOPS misalignment, you can optimize both performance and cost in your AWS environment.