how to empty buffers/cache?

how to empty buffers/cache?

[Soeren Sonnenburg]

Dear all,

I am trying to perform some benchmarks that involve reading the same big
file a couple of times from disk. However I would want to make sure that
the file is not buffered/cached by the kernel when I read the file a
second/third/etc time.

Is there a way (except rebooting/unmounting the disk) to clear the
buffers?

Thanks,
Soeren

Re: how to empty buffers/cache?

[Alejandro Riveira Fernández]

El Fri, 09 May 2008 21:49:47 +0000
Soeren Sonnenburg <kernel@nn7.de> escribió:

> Dear all,
> 
> I am trying to perform some benchmarks that involve reading the same big
> file a couple of times from disk. However I would want to make sure that
> the file is not buffered/cached by the kernel when I read the file a
> second/third/etc time.
> 
> Is there a way (except rebooting/unmounting the disk) to clear the
> buffers?

 echo 3  > /proc/sys/vm/drop_caches IIRC

> 
> Thanks,
> Soeren
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Re: how to empty buffers/cache?

[Soeren Sonnenburg]

On Sat, 2008-05-10 at 00:11 +0200, Alejandro Riveira Fernández wrote:
> El Fri, 09 May 2008 21:49:47 +0000
> Soeren Sonnenburg <kernel@nn7.de> escribió:
> 
> > Dear all,
> > 
> > I am trying to perform some benchmarks that involve reading the same big
> > file a couple of times from disk. However I would want to make sure that
> > the file is not buffered/cached by the kernel when I read the file a
> > second/third/etc time.
> > 
> > Is there a way (except rebooting/unmounting the disk) to clear the
> > buffers?
> 
>  echo 3  > /proc/sys/vm/drop_caches IIRC

thank you both very much ( echo 3 > ... is what I was looking for)

Soeren