Español
Deutsch
CPU and RAM usage get most of the attention, but disk I/O (input/output) bottlenecks are a common, less obvious cause of a slow-feeling server.
What Disk I/O Measures
It reflects how much data is being read from and written to disk per second — a database-heavy application can bottleneck here even with plenty of CPU and RAM still available.
Checking It
Tools like iostat and iotop on Linux show real-time disk activity, helping identify whether disk operations are the actual constraint.
Common Fixes
Faster storage (NVMe over SSD), database query optimization, and adding caching to reduce disk reads all address disk I/O bottlenecks directly.
