EBS volume optimization

EBS Volume Optimization

Why EBS Volume Optimization is Important

Amazon Elastic Block Store (EBS) volume optimization is critical for AWS SysOps Administrators because it directly impacts application performance, cost efficiency, and overall system reliability. Poorly optimized EBS volumes can lead to application bottlenecks, unnecessary expenses, and degraded user experience. Understanding how to properly configure and optimize EBS volumes ensures that your workloads run efficiently while maintaining cost-effectiveness.

What is EBS Volume Optimization?

EBS volume optimization refers to the process of selecting the right volume type, configuring appropriate IOPS and throughput settings, and implementing best practices to achieve optimal storage performance for your specific workload requirements. This includes:

• Choosing the correct EBS volume type (gp3, gp2, io2, io1, st1, sc1)
• Right-sizing volume capacity and performance characteristics
• Monitoring and adjusting performance metrics
• Implementing EBS-optimized instances
• Managing snapshots efficiently

How EBS Volume Optimization Works

Volume Type Selection:
- gp3: General purpose SSD with baseline 3,000 IOPS and 125 MiB/s throughput, independently scalable up to 16,000 IOPS and 1,000 MiB/s
- gp2: General purpose SSD with burst capability, 3 IOPS per GB (minimum 100 IOPS, maximum 16,000 IOPS)
- io2/io2 Block Express: High-performance SSD for mission-critical workloads, up to 64,000 IOPS per volume
- io1: Provisioned IOPS SSD, up to 64,000 IOPS per volume
- st1: Throughput-optimized HDD for frequently accessed, throughput-intensive workloads
- sc1: Cold HDD for less frequently accessed data

EBS-Optimized Instances:
EBS-optimized instances provide dedicated bandwidth between EC2 and EBS, preventing network contention. Most current generation instances are EBS-optimized by default. This ensures consistent and predictable storage performance.

Performance Monitoring:
Key CloudWatch metrics to monitor include:
- VolumeReadOps/VolumeWriteOps
- VolumeReadBytes/VolumeWriteBytes
- VolumeTotalReadTime/VolumeTotalWriteTime
- VolumeIdleTime
- VolumeQueueLength
- BurstBalance (for gp2 volumes)

IOPS and Throughput Considerations:
- Maximum IOPS is also limited by EC2 instance type
- I/O size affects whether you hit IOPS or throughput limits first
- 16 KB I/O size is used for SSD volume IOPS calculations
- 1 MB I/O size is used for HDD volume throughput calculations

Best Practices for EBS Optimization

1. Use gp3 volumes instead of gp2 for cost savings with predictable performance
2. Enable EBS-optimized mode on instances
3. Use RAID 0 configurations to aggregate performance across multiple volumes
4. Pre-warm restored volumes from snapshots for maximum performance
5. Monitor burst balance on gp2 volumes to prevent performance degradation
6. Use io2 volumes for databases requiring high durability (99.999%)
7. Implement lifecycle policies for snapshot management

Exam Tips: Answering Questions on EBS Volume Optimization

• When questions mention cost optimization with general-purpose workloads, gp3 is typically the answer as it offers lower cost than gp2 with configurable IOPS

• Questions about high IOPS requirements for databases like Oracle or SQL Server typically point to io2 or io1 volumes

• If a scenario describes big data or log processing with sequential access patterns, consider st1 (throughput-optimized HDD)

• When you see burst balance depleting or inconsistent performance on gp2, the solution is usually to increase volume size or migrate to gp3/io volumes

• Remember that only SSD volumes (gp2, gp3, io1, io2) can be boot volumes

• For questions about maximum single-volume IOPS, know that io2 Block Express can achieve up to 256,000 IOPS

• When performance issues arise after restoring from snapshots, remember that volumes need initialization - either by reading all blocks or enabling fast snapshot restore

• Questions mentioning dedicated bandwidth between EC2 and EBS are referring to EBS-optimized instances

• If asked about improving performance beyond single volume limits, consider RAID 0 striping across multiple volumes

• Watch for questions about VolumeQueueLength - high values indicate the volume cannot keep up with I/O demand