On May 23, 2008 08:11 +0800, Stuart Midgley wrote: > 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.
Sorry to not be clear - the DMU ARC will allow caching on the OSS node. > -- > Dr Stuart Midgley > [EMAIL PROTECTED] > > >>> >> >> 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. >> Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
