On Tue, Mar 06, 2007 at 08:17:32AM +0900, Stu Midgley wrote: > I can't think of any benchmark you care to mention that a single > lustre OSS/MDS won't outperform NFS.
Consider an MPI-IO benchmark where all processes write to different regions of a file. This workload is common in scientific applications, say when all processes need to write an HDF5 element to a datafile. Run that benchmark with one processor and you will get great performance out of Lustre. Lustre does an excellent job of caching data amd making single-processor I/O go really really fast. Run that benchmark with two processors, and the clients will spend a great deal of time revoking each others extent-based locks and expiring entries from their caches. Performance will take a significant hit, but will increase as you add more processes. I don't mean to come across as a Lustre hater. I'm just trying to keep the discussion honest: the discussion of the "right" file system for an application is hard, and lots of factors come into play. ==rob -- Rob Latham Mathematics and Computer Science Division A215 0178 EA2D B059 8CDF Argonne National Lab, IL USA B29D F333 664A 4280 315B _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
