[Lustre-discuss] Lustre 2.0 client cache size

[Jason Rappleye]

On Mar 18, 2011, at 1:07 AM, DEGREMONT Aurelien wrote:


>>>> Those clients do a lot of read and write in Lustre filesystems but 
>>>> thoses files will not be re-read soon, so it is useless to fill memory 
>>>> with it. Moreover, when the client memory is full, Lustre performance 
>>>> are really impacted.
>>>> 
>>> It may be possible to use fadvise(FADV_NOREUSE) from the application to cause the VM to discard these pages after the first use.
>>> 
>> Yes, that would totally make sense to do regardless of other methods.
>> 
> 
> Hmm... I do not want to patch 'cp' or 'dd' :)

You might want to have a look at this:

http://code.google.com/p/pagecache-mangagement/

We use it when copying crash dumps off of our OSSes, as we don't want to disturb cached metadata.

Jason

--
Jason Rappleye
System Administrator
NASA Advanced Supercomputing Division
NASA Ames Research Center
Moffett Field, CA 94035