root@rescue-pro:~#  fio --name=rand-rw --ioengine=libaio --directory=/mnt/sdb1 --iodepth=32 --rw=randrw --invalidate=1 --bsrange=4k:4k,4k:4k --size=512m --runtime=120 --time_based --do_verify=1 --direct=1 --group_reporting --numjobs=1
rand-rw: (g=0): rw=randrw, bs=4K-4K/4K-4K/4K-4K, ioengine=libaio, iodepth=32
fio-2.16
Starting 1 process
rand-rw: Laying out IO file(s) (1 file(s) / 512MB)
Jobs: 1 (f=1): [m(1)] [49.6% done] [1009KB/1121KB/0KB /s] [252/280/0 iops] [eta 01m:01s]ops] [eta 01m:02s]
Jobs: 1 (f=1): [m(1)] [100.0% done] [876KB/940KB/0KB /s] [219/235/0 iops] [eta 00m:00s]
rand-rw: (groupid=0, jobs=1): err= 0: pid=8628: Thu Sep 26 14:03:01 2019
  read : io=101020KB, bw=861663B/s, iops=210, runt=120052msec
    slat (usec): min=4, max=134867, avg=71.32, stdev=1804.80
    clat (usec): min=650, max=389033, avg=77319.96, stdev=33768.82
     lat (usec): min=763, max=389060, avg=77391.28, stdev=33732.06
    clat percentiles (msec):
     |  1.00th=[   20],  5.00th=[   40], 10.00th=[   47], 20.00th=[   55],
     | 30.00th=[   61], 40.00th=[   65], 50.00th=[   71], 60.00th=[   76],
     | 70.00th=[   84], 80.00th=[   95], 90.00th=[  119], 95.00th=[  141],
     | 99.00th=[  198], 99.50th=[  227], 99.90th=[  318], 99.95th=[  334],
     | 99.99th=[  379]
  write: io=101080KB, bw=862175B/s, iops=210, runt=120052msec
    slat (usec): min=5, max=95856, avg=44.38, stdev=944.13
    clat (usec): min=280, max=368800, avg=74618.62, stdev=33789.33
     lat (usec): min=306, max=368849, avg=74663.00, stdev=33776.20
    clat percentiles (msec):
     |  1.00th=[   10],  5.00th=[   38], 10.00th=[   46], 20.00th=[   53],
     | 30.00th=[   58], 40.00th=[   63], 50.00th=[   68], 60.00th=[   74],
     | 70.00th=[   81], 80.00th=[   93], 90.00th=[  115], 95.00th=[  139],
     | 99.00th=[  198], 99.50th=[  223], 99.90th=[  314], 99.95th=[  338],
     | 99.99th=[  359]
    lat (usec) : 500=0.37%, 750=0.04%, 1000=0.01%
    lat (msec) : 2=0.02%, 4=0.01%, 10=0.17%, 20=0.78%, 50=13.22%
    lat (msec) : 100=69.07%, 250=16.04%, 500=0.27%
  cpu          : usr=0.51%, sys=1.71%, ctx=45949, majf=0, minf=11
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=99.9%, >=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=0.1%, 64=0.0%, >=64=0.0%
     issued    : total=r=25255/w=25270/d=0, short=r=0/w=0/d=0, drop=r=0/w=0/d=0
     latency   : target=0, window=0, percentile=100.00%, depth=32

Run status group 0 (all jobs):
   READ: io=101020KB, aggrb=841KB/s, minb=841KB/s, maxb=841KB/s, mint=120052msec, maxt=120052msec
  WRITE: io=101080KB, aggrb=841KB/s, minb=841KB/s, maxb=841KB/s, mint=120052msec, maxt=120052msec

Disk stats (read/write):
  sdb: ios=25225/25299, merge=0/29, ticks=1940476/1884712, in_queue=3826280, util=100.00%


root@rescue-pro:~# ioping -c 5 /mnt/sdb1
4 KiB <<< /mnt/sdb1 (ext4 /dev/sdb1): request=1 time=2.19 ms (warmup)
4 KiB <<< /mnt/sdb1 (ext4 /dev/sdb1): request=2 time=7.34 ms
4 KiB <<< /mnt/sdb1 (ext4 /dev/sdb1): request=3 time=478.2 us
4 KiB <<< /mnt/sdb1 (ext4 /dev/sdb1): request=4 time=403.4 us
4 KiB <<< /mnt/sdb1 (ext4 /dev/sdb1): request=5 time=400.1 us

--- /mnt/sdb1 (ext4 /dev/sdb1) ioping statistics ---
4 requests completed in 8.62 ms, 16 KiB read, 463 iops, 1.81 MiB/s
generated 5 requests in 4.00 s, 20 KiB, 1 iops, 5.00 KiB/s
min/avg/max/mdev = 400.1 us / 2.16 ms / 7.34 ms / 2.99 ms
root@rescue-pro:~# ioping -RL /mnt/sdb1/

--- /mnt/sdb1/ (ext4 /dev/sdb1) ioping statistics ---
562 requests completed in 2.96 s, 140.5 MiB read, 189 iops, 47.5 MiB/s
generated 563 requests in 3.00 s, 140.8 MiB, 187 iops, 46.9 MiB/s
min/avg/max/mdev = 932.9 us / 5.26 ms / 57.7 ms / 6.93 ms