On Sat, Nov 12, 2011 at 11:18:04PM -0500, Bill Boas wrote: > Bart, James, Dave, > > At SC we are running a video streaming demo across a 7000 mile fiber > distance using IB extension boxes from Bay Microsystems at 40 Gbps. The > video streaming app uses SRP to transmit the streams across this long > distance link. Performance is not all what we would have hoped. We think > that because SRP uses RC mode between initiator and target that it is the RC > behavior over this distance that is impacting performance. Are any of you > aware of an SRP implementation that uses UC mode. SRP uses RDMA, so you cannot use UC mode. Your problem sounds a lot like issues we saw when starting to run over 100m+ optical cables; IIRC it required increasing the credits available the link. You should contact Jason Gunthorpe or Makia Minnich. Makia was involved in that investigation at ORNL, but Jason may also be able to tell you off the top of his head. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
