Igor Sysoev is at
Fri Aug 28 20:54:52 MSD 2009

On Fri, Aug 28, 2009 at 09:39:20AM -0700, Michael Shadle wrote:

> 2009/8/28 Igor Sysoev <is at>:
> > No, now "gzip_disable msie6" disables MSIE4/5 and 6 before SV1.
> > Early it disables any MSIE4/5/6.
> Gotcha!
> > It depends. On Linux AIO can be used with DIRECTIO only, which disables
> > caching on VM. On FreeBSD I plan to add support for sendfile()s SF_NODISKIO
> > flag. This allows to use sendfile() and AIO preload for sendfile().
> I think when they did benchmarks for Lighttpd, AIO was the fastest
> solution. Is there any benefit to caching in VM? Files requested a lot
> or small files?

If you have enough memory to cache hot content in VM, than nginx can
handle it without delay since nginx will not block on disk if AIO is used.

> > By default directio_alignment is 512, however, on XFS you may need to
> > set "directio_alignment 4k" or even more depending on FS block size.
> Is there an easy way to check blocksize? I use XFS typically.

Look for sectsz and bsize in xfsinfo.

Try to enable just directio without aio and request a file.
If you will see "Invalid argument" in error_log, then try to set
directio_alignment to sectsz or bsize. If the error will remain try
to double max of sectsz/bsize. Please report your results.

> Also, since this is DIRECTIO, this is not really a good idea over NFS
> right? I think I saw in the Linux kernel that DIO support in NFS was
> experimental etc. but I'm not sure I'll get much benefit out of it...

I do not know.

Igor Sysoev

More information about the nginx mailing list