What is iowait and how does it affect Linux performance?

Originally published at: What is iowait and how does it affect Linux performance?

iowait (wait, wa, %iowait, wait%, or I/O wait) is often displayed by command-line Linux system monitoring tools such as top, sar, atop, and others. On its own, it’s one of many performance stats that provide us insight into Linux system performance. I/O wait came up in a recent discussion with a new client. During our support…