Re: O_DIRECT please; Sybase 12.5

From: Daryll Strauss (daryll@valinux.com)
Date: Tue Jul 03 2001 - 10:10:39 EST


On Tue, Jul 03, 2001 at 10:42:53AM +0100, Stephen C. Tweedie wrote:
> On Fri, Jun 29, 2001 at 02:39:00AM -0700, Dan Kegel wrote:
>
> > It supports raw partitions, which is good; that might satisfy my
> > boss (although the administration will be a pain, and I'm not
> > sure whether it's really supported by Dell RAID devices).
>
> All block devices support raw IO --- the raw IO mechanism talks to the
> device driver through the normal kernel-internal block IO entry
> points.
>
> > I'd prefer O_DIRECT :-(
>
> Andrea Arcangeli has already posted patches you can try for ext2. The
> functionality isn't in the mainline kernel yet, though.

I recall hearing about a problem with the md device and raw IO. It was
something about the block sizes not matching causing performance
problems. Has anything been done to improve those issues?

                                            - |Daryll
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Jul 07 2001 - 21:00:12 EST