Re: "Invalidate" not functional on Windows?

Re: "Invalidate" not functional on Windows?

[Greg Sullivan]

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!!

Regards.,
Greg.

Re: "Invalidate" not functional on Windows?

[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.

-- 
Jens Axboe

Re: "Invalidate" not functional on Windows?

[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.

-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

Re: "Invalidate" not functional on Windows?

[Bruce Cran]

On 14/08/2012 18:33, Martin Steigerwald wrote:
> 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.

On Windows (windowsaio) use sync=1 to disable buffering of writes. For 
reads, use direct=1.

-- 
Bruce Cran

Re: "Invalidate" not functional on Windows?

[Martin Steigerwald]

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
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7