[CentOS] Very slow disk I/O

Wed Jan 28 12:51:34 UTC 2015
Nicolas Thierry-Mieg <Nicolas.Thierry-Mieg at imag.fr>

On 01/28/2015 01:32 PM, Jatin Davey wrote:
> Hi Users
>
> I am using RHEL 6.5 on my server.
>
>  From top command i can see that the processors in my server are
> spending a lot of time on wait for I/O.
> I can see high percentage in terms of 30-50% on "wa" time.
>
> Here is the df output about the disk space in my system:
>
> **********
> [root at localhost images]# df
> Filesystem      1K-blocks      Used  Available Use% Mounted on
> /dev/sda1      1915071844 103227908 1714563936   6% /
> tmpfs            32931472         0   32931472   0% /dev/shm
> **********
>
> Could someone point me on how to improve the disk I/O on my server and
> reduce the wait time on I/O.

you could use iotop or vmstat to see what processes are causing the IO.