[Lustre-discuss] user space lustre

[Stuart Midgley]

Right.  So I am still not clear whether 64GB oss's will be of any  
benefit.  My understanding at the moment is that oss's don't benefit  
from larger memory, hence we run with 2GB.


--
Dr Stuart Midgley
sdm900 at gmail.com


>>
>
> The implementation of ZFS is segmented into several major functional
> units.  The data management unit (DMU) is the bulk of the on-disk
> structure and is what Lustre will actually interface with for the  
> MDT/OST.
> The adaptive replacement cache (ARC) is the cache management code and
> is used to manage manage memory in both userspace and the Solaris  
> kernel.
>
> As a result, the userspace servers do not benefit at all from having a
> duplicate kernel-side cache, like any large database implementation,
> so we will be avoiding that as best possible.  Initially we were doing
> O_DIRECT IO, but using async IO (libaio) showed much better  
> performance
> for the way the ARC submits IO to disk.
>
> Cheers, Andreas
> --
> Andreas Dilger
> Sr. Staff Engineer, Lustre Group
> Sun Microsystems of Canada, Inc.
>