HDD util is 100% - aio questions

Valentin V. Bartenev vbart at nginx.com
Mon Jan 28 17:46:38 UTC 2013

On Monday 28 January 2013 10:53:52 Cristian Rusu wrote:
> Hello
> Right now nginx manages to put hdds in the server to high util rate.
> I try to run Nginx 1.2.3 with aio support to deliver mp4 videos with the
> streaming module.
> I compiled the server with aio and it starts fine.
> In config I set it like this
>     directio 512;

So, you effectively switched off the page cache for any response longer
than 512 bytes.

> I read that sendfile should be off, but it won't send video unless I turn
> it on.

No, it should not for Linux.

> In this case does aio work at all? How can I tell, before I wait a week and
> see that maybe HDD util is not 100% all the time anymore :P

It seems, and you have almost all the data read directly from drive,
which is resulted in 100% disk utilization.

  wbr, Valentin V. Bartenev


> ---------------------------------------------------------------
> Cristian Rusu
> Web Developement & Electronic Publishing
> ======
> Crilance.com
> Crilance.blogspot.com

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