Disk I/O Performance Diagnosis and Optimization
Introduction Disk I/O is often the slowest link in the system performance chain. A single mechanical disk seek takes about 10ms, while memory access takes only about 100ns — a 100,000x difference. When business applications experience latency jitter or slow response times, the investigation inevitably points to the I/O subsystem. This article starts from the metrics system, combined with hands-on tool usage and production case studies, to build a reusable I/O diagnosis methodology....