On Mon, Jul 11, 2011 at 12:37:08PM -0700, Matthew Dillon wrote: > > There's something very basic wrong. How much memory does the machine > have?
32GB. I didn't think too much memory could be a liability. > Blogbench clearly isn't running long enough to blow out the > system caches. Try more iterations: > > blogbench --iterations=100 I get 1583 / 311957. I will have to test on different configurations to find out if the numbers make sense. > Otherwise you aren't testing the disk drives at all. There was definitely some disk activity. And there was more at the start of the benchmark than at the end. I've kept a log of "iostat da0 1" output. It's as if something was limiting the number of iops > w/regards to the CAM fix, to determine if it is meaningful use > /usr/src/test/sysperf/randread.c. The default parameters should be > sufficient. Run it on the raw disk block device (it should work for > FreeBSD too but I'm not sure lseek will properly size the drive). > > cd /usr/src/test/sysperf > make /tmp/rr1 > > Serialized disk reads will show up at around ~150-200 tps. Multi-tagged > disk reads will show up in the 400-500 tps range. If I interpret the results correctly, I get 1000-1300 iops: randread 1.000s 1287 loops = 777.047uS/loop randread 1.000s 1288 loops = 776.438uS/loop randread 1.000s 1282 loops = 780.059uS/loop randread 1.000s 1314 loops = 761.074uS/loop randread 1.000s 1043 loops = 958.813uS/loop randread 1.000s 1282 loops = 780.075uS/loop randread 1.000s 1326 loops = 754.184uS/loop randread 1.000s 1195 loops = 836.863uS/loop randread 1.000s 1179 loops = 848.221uS/loop With 16KB requests, the numbers are in the 1400-1600 tps range: randread 1.000s 1509 loops = 662.727uS/loop randread 1.000s 1531 loops = 653.212uS/loop randread 1.000s 1479 loops = 676.168uS/loop randread 1.000s 1575 loops = 634.956uS/loop randread 1.000s 1418 loops = 705.241uS/loop randread 1.000s 1536 loops = 651.066uS/loop randread 1.000s 1645 loops = 607.927uS/loop randread 1.000s 1472 loops = 679.379uS/loop randread 1.000s 1457 loops = 686.371uS/loop -- Francois Tigeot
