Re: "Invalidate" not functional on Windows?

[Martin Steigerwald <Martin@lichtvoll.de>]

Am Dienstag, 14. August 2012 schrieb Martin Steigerwald:
> Am Dienstag, 14. August 2012 schrieb Jens Axboe:
> > On 08/14/2012 06:57 AM, Greg Sullivan wrote:
> > > I need to perform reads without using any caching. I have the line
> > > "invalidate=1" in my job file, however it is still using the cache.  I
> > > am running Windows 7 32-bit. Is the "invalidate" command supposed to
> > > be functional on Windows? If so, what am I doing wrong?
> > > 
> > > That aside, what a great utility this is - thankyou!!
> > 
> > As far as what I remember from talking/mailing with Bruce (CC'ed),
> > there's no way to invalidate the cache in Windows.
> 
> invalidate discards the buffer cache before the job group is started.
> During the job execution caches will be in use anyway. Unless using
> direct I/O (direct=1). Don´t know whether direct I/O will work with
> "windowsaio" I/O engine or in any other way on Windows.

Hey, its even documented. Except from HOWTO:

direct=bool     If value is true, use non-buffered io. This is usually
                O_DIRECT. Note that ZFS on Solaris doesn't support direct io.
                On Windows the synchronous ioengines don't support direct io.

-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
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