[OpenIndiana-discuss] ISCSI SSD Performance

[Grant Albitz]

I would like to discuss one more item:

Based on the writes below vs the reads it seems like I am able to get more data out of a w/s as apposed to a read per second. I may just be misunderstanding the results but the disks themselves are rated for higher read performance then write. I am just wondering if there is a zfs tunable I can play with. The disks seem have much more queued up during writes then reads as well.


time dd if=/dev/zero of=/PSC.Net/dd.tst bs=2048000 count=131027
r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device
    0.0    0.0    0.0    0.0  0.0  0.0    0.0    0.0   0   0 c1t24d0
    0.0    0.0    0.0    0.0  0.0  0.0    0.0    0.0   0   0 c2t0d0
    0.0 1057.2    0.0 89869.6  0.0  9.6    0.0    9.1   1  67 c1t0d0
    0.0 1057.2    0.0 89852.5  0.0  9.6    0.0    9.1   1  67 c1t1d0
    0.0 1057.4    0.0 89946.6  0.0  9.6    0.0    9.1   1  66 c1t2d0
    0.0 1057.0    0.0 89912.4  0.0  9.6    0.0    9.1   1  67 c1t3d0
    0.0 1038.0    0.0 87068.1  0.0  9.5    0.0    9.1   1  66 c1t4d0
    0.0 1037.2    0.0 87015.8  0.0  9.5    0.0    9.1   1  66 c1t5d0
    0.0 1037.0    0.0 87076.6  0.0  9.5    0.0    9.2   1  66 c1t6d0

time dd if=/PSC.Net/dd.tst of=/dev/null bs=2048000
  r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device
    0.0    0.0    0.0    0.0  0.0  0.0    0.0    0.0   0   0 c1t24d0
    0.0    0.0    0.0    0.0  0.0  0.0    0.0    0.0   0   0 c2t0d0
  884.1    0.0 38373.3    0.0  0.0  0.3    0.0    0.4   1  13 c1t0d0
  873.7    0.0 38425.6    0.0  0.0  0.3    0.0    0.4   1  14 c1t1d0
  883.5    0.0 38399.9    0.0  0.0  0.3    0.0    0.4   1  13 c1t2d0
  875.1    0.0 38408.2    0.0  0.0  0.3    0.0    0.4   1  13 c1t3d0
  876.5    0.0 38528.1    0.0  0.0  0.3    0.0    0.4   1  13 c1t4d0
  880.7    0.0 38520.2    0.0  0.0  0.3    0.0    0.4   1  14 c1t5d0
  874.9    0.0 38510.4    0.0  0.0  0.3    0.0    0.4   1  13 c1t6d0