Which OS best for file serving? Does file AIO increase performance significantly?

[Igor Sysoev]

On Tue, Aug 23, 2011 at 03:05:01PM +0800, Sharl.Jimh.Tsin wrote:
> 在 2011-08-22一的 10:58 -0400，Andy写道：
> > Hi,
> > 
> > I'm interested in setting up Nginx server for image serving, mostly
> > small images such as icons or thumbnails.
> > 
> > Usually I use Linux, but I understand that file AIO doesn't work on
> > Linux. A few questions:
> > 
> > 1) How much performance increase does file AIO realistically provide for
> > file serving - 10%? 50%? 100%?
> > 
> > 2) If the performance increase is significant, which OS do you recommend
> > for file AIO - FreeBSD, NetBSD, Open BSD, OpenSolaris?
> > 
> > 3) Is it a steep learning curve moving from Linux to one of the
> > aforementioned OS?
> > 
> > Thanks.
> > 
> > Posted at Nginx Forum: http://forum.nginx.org/read.php?2,214148,214148#msg-214148
> > 
> > _______________________________________________
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> > nginx at nginx.org
> > http://mailman.nginx.org/mailman/listinfo/nginx
> 
> Why do you think that File AIO not work on GNU/Linux?
> 
> In nginx website(ABOUT page),it says: "File AIO (FreeBSD 4.3+, Linux
> 2.6.22+); "

nginx supports Linux AIO. However, Linux AIO works only together with
O_DIRECT, that means that all I/O must be aligned to sector boundary
(usually 512 bytes) and are not cached by the kernel.


-- 
Igor Sysoev