On May 18, 2007 07:56 -0400, John R. Dunning wrote: > 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
For a DDN you should probably use noop or deadline scheduler. Anticipatory is really tuned for desktop workloads. > 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. What tool are you using to measure performance? I'd strongly suggest using the lustre-iokit, which has several components in order to test bare-disk, local filesystem, network, and lustre-filesystem components independently. Lustre can consistently generate 1MB IOs to the underlying filesystem because it submits the IO in 1MB chunks, unlike the kernel's read() and write() calls which submit IO in 4kB chunks and hope the elevator can merge them. See also the DDN tuning section in the Lustre manual. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. _______________________________________________ Lustre-discuss mailing list [email protected] https://mail.clusterfs.com/mailman/listinfo/lustre-discuss
