What is iowait in iostat?

Percentage of time that the CPU or CPUs were idle during which the system had an outstanding disk I/O request. when iowait is considered to be high ? iostat -x avg-cpu: %user %nice %system %iowait %steal %idle 2,89 0,01 5,. The reason I/O Wait is difficult to troubleshoot is due to the fact that by. iostat -m 5 avg-cpu: %user %nice %system %iowait %steal %idle 8. iowait is time that the processor/processors are waiting (i. Generate i/o statistics report with iostat and nfsiostat command.