+1
And remember that I/O is more than just disk. The atop monitor gives you
information like top and htop, but also provides a lot of I/O information as
well including network. Perhaps your server is the target of a network-based
DDOS attack which can cause lots of I/O wait time. Also look at top to see what
numbers are in the si and hi columns. THese stand for software and hardware
interrupts. If one of those is high you can also narrow it down.
Hope this helps.
On 01/28/2015 07:51 AM, Nicolas Thierry-Mieg wrote:
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@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.
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