On Mon, 2011-02-14 at 09:46 -0600, Cory Spitz wrote: > You will find that async jounral commits don't help O_DIRECT I/O though. > So, maybe you should think about using both.
It definitely depends on your workload. It's not in the paper at http://www.usenix.org/events/fast10/tech/full_papers/oral.pdf but I seem to recall that using external journals in conjunction with async commits reduced the performance benefits from the async commits. There does seem to be some bottlenecks with the external journalling code paths, but since async worked so well for our workloads, we never tried to run them down. -- Dave Dillow National Center for Computational Science Oak Ridge National Laboratory (865) 241-6602 office _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
