How to see IOWAIT in Linux

Hello ,

You can use sar command.

in Ubuntu you can install it with

sudo apt-get install systat

and enable data collecting

sed -i 's/ENABLED="false"/ENABLED="true"/' /etc/default/sysstat

start service with

 

/etc/init.d/sysstat start

To see I/O latency type command as

sar 1 1

that means it will give two responses with 1 sec as interval.

Example :

root@virt01:~# sar 1 3
Linux 3.19.0-42-generic (virt01.ubuntu.com)     13/02/16        _x86_64_        (1 CPU)


12:26:23        CPU     %user     %nice   %system   %iowait    %steal     %idle
12:26:24        all      0.00      0.00      0.00      0.00      0.00    100.00
12:26:25        all      0.00      0.00      0.99      0.00      0.00     99.01
12:26:26        all      2.02      0.00      0.00      0.00      0.00     97.98
Average:        all      0.67      0.00      0.33      0.00      0.00     99.00
root@virt01:~#

Hope that helps.