Reduce I/O Latency for SAP HANA: Switch to io2 Block Express

Quick Answer

High I/O latency on EBS gp2 volumes for a SAP HANA data volume is a classic symptom of gp2's performance model, where throughput and IOPS are tied to volume size and a burst-credit mechanism, so sustained heavy I/O can exhaust burst capacity and leave the workload running at a much lower baseline performance with higher latency. Switching to io2 Block Express addresses this at the root because it's built for consistently high, predictable performance rather than burstable performance - it delivers sub-millisecond latency and can scale up to 256,000 IOPS per volume, values that gp2 simply isn't designed to sustain. That predictability matters specifically for SAP HANA because the database is highly sensitive to I/O latency for its data and log persistence operations; inconsistent or degraded storage performance translates directly into slower transaction processing and query response times. The key distinction to hold onto between the two volume types is that gp2 is a general-purpose volume type suited for a broad range of workloads with moderate, bursty I/O needs, while io2 Block Express is purpose-built for the most demanding, latency-sensitive, high-IOPS workloads, which is exactly the category SAP HANA falls into for production use. Whenever a question describes high latency or inconsistent performance on gp2 volumes for a demanding database workload like HANA, expect the fix to involve moving to a higher-performance, provisioned-IOPS volume type like io2 Block Express rather than tuning the existing volume.