Описание тега iowait
Iowait - это время, когда ЦП находится в состоянии ожидания, ожидая завершения операций ввода-вывода.
In UNIX/Linux systems, iowait is the amount of time or percentage of time, in which the CPU is idle and waits for completion of IO-operations. This state of the CPU can be seen in the output of the top-command under wa.
To test the behavior of this value (to produce iowait-time),e.g. the dd-command can be used:
dd if=/dev/sda of=/dev/null
Note that if there is an other process that is using the same CPU as this command, it is possible that the other process is using this CPU and the CPU won't be in idle state nor in iowait-state.