On Friday 18 May 2007 10:06:35 am Daniel Leaberry wrote: > John R. Dunning wrote: > > I'm getting my first exposure to a ddn storage array and it's > > enlightening :-} > > > > Mostly it just does what I expected of it with little trouble, but I'm > > having hard time getting the read side working as fast as it ought to be > > able to go. Does anybody have experience they'd like to share, tuning the > > kernel/driver or the array? > > > > I'm using 2.6.15 kernel, and qlogic 2462 hbas with 8.01.07 driver. Using > > the anticipatory scheduler, and tweaking up the readahead size for the > > blockdev, I can get around 300MB/s by using 4 threads on a port, or about > > 3/4 of the expected max. Writes max out easily. The ddn's stats say > > that the large majority of my reads are only 256K, even though the > > requests are larger than that. > > > > I tried incorporating the blkdev-max-io-size-selection and > > increase-sglist-size patches from cfs, but that didn't really help, my > > reads are still maxing out at 256K. > > > > If anybody's been through this kind of thing and has experiences, rumors, > > or war stories about what kinds of tuning in this area yield good > > results, I'd love to talk to you! > > I know this won't help you but for posterities sake use IBGD 1.8.2 if > you have an infiniband DDN array. I tried for 4 days with OFED 1.1.1 to > get decent io performance and never could. 30 minutes to install IBGD > and I was pushing 700MB/sec through the port using dd.
Do you have actual numbers for your OFED test? If so, please send a message to the OpenFabrics General mailing list ([EMAIL PROTECTED]) letting them know of this performance degredation. The more details we have of a slow-down in the SRP performance, the more chance we have of OFED finally fixing whatever the problem is (or at least getting Mellanox to pony up what is the difference between IBGD's and OFED's SRP client code and explain why they haven't submitted changes). > > _______________________________________________ > > Lustre-discuss mailing list > > [email protected] > > https://mail.clusterfs.com/mailman/listinfo/lustre-discuss > > _______________________________________________ > Lustre-discuss mailing list > [email protected] > https://mail.clusterfs.com/mailman/listinfo/lustre-discuss -- Makia Minich <[EMAIL PROTECTED]> National Center for Computation Science Oak Ridge National Laboratory Phone: 865.574.7460 --*-- Imagine no possessions I wonder if you can - John Lennon _______________________________________________ Lustre-discuss mailing list [email protected] https://mail.clusterfs.com/mailman/listinfo/lustre-discuss
