How to Measure IOPS Using fio

it is important that your swimlane instance meets the minimum required iops, otherwise severe performance degradation can result also, you risk your instance being unsupported by swimlane this article describes one way to measure iops using the fio tool note because of file caching, the results of fio can vary depending on when you run the command to reduce that variance, we recommend running fio several times a day over a couple of days and averaging the result install fio if not already installed fedora based linux (e g red hat, centos) $ sudo yum install fio debian based linux (e g ubuntu) $ sudo apt get install fio then run this command on each of your cluster nodes it will run for a few minutes with output that updates in real time; when it's finished it, will have final output similar to this $ fio name=random write ioengine=posixaio rw=randwrite bs=4k numjobs=1 size=4g iodepth=1 runtime=60 time based end fsync=1 random write (g=0) rw=randwrite, bs=(r) 4096b 4096b, (w) 4096b 4096b, (t) 4096b 4096b, ioengine=posixaio, iodepth=1 fio 3 7 starting 1 process random write laying out io file (1 file / 4096mib) jobs 1 (f=1) \[f(1)]\[100 0%]\[r=0kib/s,w=0kib/s]\[r=0,w=0 iops]\[eta 00m 00s] random write (groupid=0, jobs=1) err= 0 pid=4168 thu aug 19 11 09 57 2021 write iops=3994, bw=15 6mib/s (16 4mb/s)(2449mib/156935msec) slat (nsec) min=1681, max=105529k, avg=4310 96, stdev=142005 21 clat (nsec) min=820, max=228958k, avg=89450 02, stdev=1359359 52 lat (usec) min=11, max=228961, avg=93 76, stdev=1370 29 clat percentiles (usec) \| 1 00th=\[ 11], 5 00th=\[ 12], 10 00th=\[ 14], 20 00th=\[ 16], \| 30 00th=\[ 19], 40 00th=\[ 20], 50 00th=\[ 20], 60 00th=\[ 21], \| 70 00th=\[ 23], 80 00th=\[ 29], 90 00th=\[ 36], 95 00th=\[ 48], \| 99 00th=\[ 130], 99 50th=\[ 791], 99 90th=\[21103], 99 95th=\[28967], \| 99 99th=\[50070] bw ( kib/s) min= 3787, max=227400, per=100 00%, avg=41644 82, stdev=54714 18, samples=120 iops min= 946, max=56850, avg=10411 00, stdev=13678 61, samples=120 lat (nsec) 1000=0 01% lat (usec) 2=0 01%, 4=0 01%, 10=0 01%, 20=52 57%, 50=42 84% lat (usec) 100=3 25%, 250=0 65%, 500=0 13%, 750=0 05%, 1000=0 04% lat (msec) 2=0 08%, 4=0 05%, 10=0 09%, 20=0 13%, 50=0 10% lat (msec) 100=0 01%, 250=0 01% cpu usr=2 06%, sys=2 00%, ctx=627931, majf=0, minf=50 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 rwts total=0,626892,0,1 short=0,0,0,0 dropped=0,0,0,0 latency target=0, window=0, percentile=100 00%, depth=1 run status group 0 (all jobs) write bw=15 6mib/s (16 4mb/s), 15 6mib/s 15 6mib/s (16 4mb/s 16 4mb/s), io=2449mib (2568mb), run=156935 156935msec disk stats (read/write) dm 0 ios=453/462780, merge=0/0, ticks=1795/7586994, in queue=7615234, util=93 05%, aggrios=453/460952, aggrmerge=0/1823, aggrticks=1795/7571606, aggrin queue=7572764, aggrutil=92 87% sda ios=453/460952, merge=0/1823, ticks=1795/7571606, in queue=7572764, util=92 87% using this piece of the output ”… write bw=15 6mib/s ( 16 4 mb/s), 15 6mib/s 15 6mib/s (16 4mb/s 16 4mb/s)… …” convert the number in bold to iops using this formula ( mbps throughput / 4) 1024 in this example iops = ( 16 4 /4) 1024 = 4198 4 if the bold number is less than 11 7 mb/s, then you do not meet the minimum required 3000 iops