> Randread is a single threaded test, it will never do > more than one > simultaneous read. So you can't get more reads/sec > than one disc can > deliver. You have to have more than one simultaneous > read to get more. > Try running several randread at the same time.
Doh, ofcourse. When running 2 parallell I still got 66 reads/sec per process, though 4 and 8 only gave 33 reads/sec. Its composed of 9 drives. While it is in now way optimized way of testing, 33 r/s * 4 = 132 r/s on 9 drives which should theoretically give 9 * 66 r/s = 594 is still rather far off. The original problem which I didn't describe in my first post was that of terrible resync performance, 6 MB/s. Now one of the stripes still have default stripe size of 16k, when both had default stripe size I got about 7 MB/s. An iostat looks like this. device r/s w/s kr/s kw/s wait actv svc_t %w %b us sy wt id md20 93.4 93.2 5977.6 5964.8 0.0 1.0 5.4 0 100 md21 466.6 0.0 5971.2 0.0 0.0 0.3 0.7 0 9 md22 0.0 93.2 0.0 5964.8 0.0 0.9 9.8 0 91 sd31 0.0 20.2 0.0 644.0 0.0 0.2 9.5 0 10 sd32 0.0 19.2 0.0 614.4 0.0 0.2 9.6 0 10 sd33 0.0 25.4 0.0 815.2 0.0 0.2 9.6 0 13 sd34 0.0 19.2 0.0 614.4 0.0 0.2 9.5 0 10 sd35 0.0 19.2 0.0 614.4 0.0 0.2 9.5 0 10 sd37 0.0 19.2 0.0 614.4 0.0 0.2 9.4 0 10 sd39 0.0 25.6 0.0 819.2 0.0 0.2 9.4 0 13 sd40 0.0 19.2 0.0 614.4 0.0 0.2 9.4 0 10 sd42 0.0 19.2 0.0 614.4 0.0 0.2 9.6 0 10 sd43 51.8 0.0 664.8 0.0 0.0 0.0 0.5 0 3 sd44 52.0 0.0 665.6 0.0 0.0 0.0 0.8 0 4 sd45 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 sd46 51.8 0.0 662.4 0.0 0.0 0.0 0.5 0 3 sd47 51.8 0.0 662.4 0.0 0.0 0.0 0.6 0 3 sd48 51.8 0.0 662.4 0.0 0.0 0.0 0.6 0 3 sd49 51.8 0.0 662.4 0.0 0.0 0.0 0.6 0 3 sd50 51.8 0.0 663.2 0.0 0.0 0.0 0.7 0 4 sd51 51.8 0.0 662.4 0.0 0.0 0.0 0.8 0 4 sd52 51.8 0.0 662.4 0.0 0.0 0.0 0.8 0 4 At first I thought there might be something wrong with the FC switch used for the devices on md22, but I got the full speed sequential test results using it, etc. The disks are obviously lazying thru the whole process. Should it be this slow? Nothing else is using those disks. Any one disk is capable of about 33 MB/s sequential read(tested). If I start dd if=/dev/md/dsk/d22 of=/dev/null bs=16k (d22 is the device being synced into the mirror) I get about 20 MB/s read and resync drops to about 3.5 MB/s. Same if I try it on d21 or d20 (which is the mirror device). So there is clearly bandwith available. When I recreate d21 to have 1M stripe size will it resync faster? What I really wondering is about the 9/91% busy on d21/d22. When I first added d22, with default stripe size, it wouldn't give any test reads the time of day, though I had a ftp transfer writing about 7 MB/s. But the total bandwidth didn't really exceed 7 MB/s. Any insights greatly appreciated. /Samuel This message posted from opensolaris.org _______________________________________________ storage-discuss mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/storage-discuss
