simple minded sprints with JackRabbit Flash

A quick and dirty test on a JackRabbit Flash machine. This is a machine going to a proof of concept project soon.

A simple 8k random read against 256GB data spread out over 4 volumes. 1 machine. 48GB ram.

Open up the throttle on the stock config. Engines aren’t running at full speed, but its a baseline test.

random: (groupid=0, jobs=256): err= 0: pid=18717
  read : io=262144MB, bw=733052KB/s, iops=91631, runt=366189msec
    clat (usec): min=296, max=184778, avg=2777.65, stdev=22.14
    bw (KB/s) : min=    5, max=16256, per=0.39%, avg=2878.49, stdev= 5.78
  cpu          : usr=0.16%, sys=1.08%, ctx=69011028, majf=1, minf=87227
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w: total=33554432/0, short=0/0
     lat (usec): 500=0.02%, 750=0.02%, 1000=0.02%
     lat (msec): 2=0.13%, 4=99.63%, 10=0.16%, 20=0.01%, 50=0.01%
     lat (msec): 100=0.01%, 250=0.01%

Run status group 0 (all jobs):
   READ: io=262144MB, aggrb=733051KB/s, minb=750644KB/s, maxb=750644KB/s, mint=366189msec, maxt=366189msec

Disk stats (read/write):
  sdf: ios=16775284/0, merge=0/0, ticks=22949090/0, in_queue=22940080, util=24.97%
  sdh: ios=16776371/170953, merge=0/16346044, ticks=23011130/44960740, in_queue=67962970, util=47.32%
  sdg: ios=16776714/170877, merge=0/16346137, ticks=23010180/44923810, in_queue=67925390, util=63.18%
  sdi: ios=16774598/171025, merge=0/16345986, ticks=23002660/44961430, in_queue=67955380, util=95.08%

91k IOPs.

Not bad. But have to tune it a bit.

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One thought on “simple minded sprints with JackRabbit Flash

  1. Joe,

    Just for grins it might be interesting to take some of the 48GB and make a ram disk and run the same tests on smaller files. This would give you an upper bound. Then you could “rank” the disk, flash, and ram systems relative to one another (i.e. where does flash fall in the spectrum). I would love to do this but I can’t afford good flash drives on my own dime 🙁


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