Re: Random file I/O regressions in 2.6

Peter Zaitsev
2004-05-07T01:29:46Z

On Thu, 2004-05-06 at 16:49, Nick Piggin wrote:

> >
> > `nomtime' would be simpler and safer to implement, but not as nice.
> >
> > But we need those numbers first. I'll take a look.
> >
>
> Can they use fdatasync? Does it do the right thing on Linux?

Nick,

You're right. fdatasync suppose to be solution in this case and actually
test supports this mode as well as MySQL does :)

On other hand if you rather use O_DSYNC it does not seems to work being
mapped to O_SYNC.

But the thing I'm mostly interested in is O_DIRECT. It seems to be the
best solution for many database needs, especially used together with
asynchronous IO. There is however no matching option which should not
flush MetaData.

--
Peter Zaitsev, Senior Support Engineer
MySQL AB, www.mysql.com