On Tue, Aug 08, 2006 at 09:54:16AM -0700, Robert Milkowski wrote: > Hi. > > snv_44, v440 > > filebench/varmail results for ZFS RAID10 with 6 disks and 32 disks. > What is suprising is that the results for both cases are almost the same! > > > > 6 disks: > > IO Summary: 566997 ops 9373.6 ops/s, (1442/1442 r/w) 45.7mb/s, > 299us cpu/op, 5.1ms latency > IO Summary: 542398 ops 8971.4 ops/s, (1380/1380 r/w) 43.9mb/s, > 300us cpu/op, 5.4ms latency > > > 32 disks: > IO Summary: 572429 ops 9469.7 ops/s, (1457/1457 r/w) 46.2mb/s, > 301us cpu/op, 5.1ms latency > IO Summary: 560491 ops 9270.6 ops/s, (1426/1427 r/w) 45.4mb/s, > 300us cpu/op, 5.2ms latency > > > > Using iostat I can see that with 6 disks in a pool I get about 100-200 IO/s > per disk in a pool, and with 32 disk pool I get only 30-70 IO/s per disk in a > pool. Each CPU is used at about 25% in SYS (there're 4 CPUs). > > Something is wrong here.
It's possible that you are CPU limited. I'm guessing that your test uses only one thread, so that may be the limiting factor. We can get a quick idea of where that CPU is being spent if you can run 'lockstat -kgIW sleep 60' while your test is running, and send us the first 100 lines of output. It would be nice to see the output of 'iostat -xnpc 3' while the test is running, too. --matt _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
