<p><pre><code>  ~# fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test --filename=test --bs=4k --iodepth=16 --size=4G --readwrite=randread

  test: (groupid=0, jobs=1): err= 0: pid=17457: Thu Sep  3 12:39:10 2015
   read : io=0B, bw=115612KB&#x2F;s, iops=28903, runt= 36279msec
   cpu          : usr=17.12%, sys=67.12%, ctx=35506, majf=0, minf=39
   IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, &gt;=64=0.0%
      submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, &gt;=64=0.0%
      complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, &gt;=64=0.0%
      issued    : total=r=1048576&#x2F;w=0&#x2F;d=0, short=r=0&#x2F;w=0&#x2F;d=0

  Run status group 0 (all jobs):
    READ: io=4096.0MB, aggrb=115612KB&#x2F;s, minb=115612KB&#x2F;s, maxb=115612KB&#x2F;s, mint=36279msec, maxt=36279msec

  Disk stats (read&#x2F;write):
   nbd0: ios=55484&#x2F;53, merge=0&#x2F;587, ticks=134950&#x2F;1020, in_queue=135900, util=24.02%

  ~# fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test --filename=test --bs=4k --iodepth=16  --size=4G --readwrite=randwrite

  test: (groupid=0, jobs=1): err= 0: pid=17460: Thu Sep  3 12:43:54 2015
   write: io=0B, bw=15741KB&#x2F;s, iops=3935, runt=266460msec
   cpu          : usr=3.97%, sys=25.75%, ctx=544104, majf=0, minf=23
   IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, &gt;=64=0.0%
      submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, &gt;=64=0.0%
      complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, &gt;=64=0.0%
      issued    : total=r=0&#x2F;w=1048576&#x2F;d=0, short=r=0&#x2F;w=0&#x2F;d=0

  Run status group 0 (all jobs):
   WRITE: io=4096.0MB, aggrb=15740KB&#x2F;s, minb=15740KB&#x2F;s, maxb=15740KB&#x2F;s, mint=266460msec, maxt=266460msec

  Disk stats (read&#x2F;write):
   nbd0: ios=0&#x2F;1053524, merge=0&#x2F;106948, ticks=0&#x2F;4282740, in_queue=4281210, util=100.00%

  ~# fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test --filename=test --bs=4k --iodepth=128 --size=4G --readwrite=randwrite

  test: (groupid=0, jobs=1): err= 0: pid=17463: Thu Sep  3 12:48:26 2015
   write: io=0B, bw=16400KB&#x2F;s, iops=4100, runt=255749msec
   cpu          : usr=4.20%, sys=22.28%, ctx=576266, majf=0, minf=23
   IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=0.1%, &gt;=64=100.0%
      submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, &gt;=64=0.0%
      complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, &gt;=64=0.1%
      issued    : total=r=0&#x2F;w=1048576&#x2F;d=0, short=r=0&#x2F;w=0&#x2F;d=0

  Run status group 0 (all jobs):
   WRITE: io=4096.0MB, aggrb=16400KB&#x2F;s, minb=16400KB&#x2F;s, maxb=16400KB&#x2F;s, mint=255749msec, maxt=255749msec

  Disk stats (read&#x2F;write):
   nbd0: ios=0&#x2F;1047606, merge=0&#x2F;56, ticks=0&#x2F;32543280, in_queue=32545150, util=100.00%

  ~# fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test --filename=test --bs=4k --iodepth=128 --size=4G --readwrite=randread

  test: (groupid=0, jobs=1): err= 0: pid=9439: Thu Sep  3 12:48:32 2015
   read : io=0B, bw=28594KB&#x2F;s, iops=7148, runt=146685msec
   cpu          : usr=8.60%, sys=31.77%, ctx=591701, majf=0, minf=138
   IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=0.1%, &gt;=64=100.0%
      submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, &gt;=64=0.0%
      complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, &gt;=64=0.1%
      issued    : total=r=1048576&#x2F;w=0&#x2F;d=0, short=r=0&#x2F;w=0&#x2F;d=0
      latency   : target=0, window=0, percentile=100.00%, depth=128

  Run status group 0 (all jobs):
    READ: io=4096.0MB, aggrb=28593KB&#x2F;s, minb=28593KB&#x2F;s, maxb=28593KB&#x2F;s, mint=146685msec, maxt=146685msec

  Disk stats (read&#x2F;write):
   nbd0: ios=1047291&#x2F;4, merge=0&#x2F;1, ticks=18660030&#x2F;50, in_queue=18659150, util=100.00%</code></pre>