Guys need pointer on calculating disk IOPS at OS level ( using command , such as iostat etc ) I am running a FIO job and at the same time monitoring bandwidth / IOPS using iostat command. What i found is FIO reports total IOPS as 431 ( 215 read , 216 write, see below output ) , but iostat r/s and w/s reports in the magnitude of a few thousands. So my query is #1 : Is r/s and w/s fields in iostat output corresponds to read and write IOPS ? ( https://serverfault.com/questions/342273/disk-iops-count-in-gnu-linux mentions r/s and w/s as IOPS) #2 : If yes then why does they dont match with FIO IOPS results ? #4 : Whats your favourite command / tool to monitor system IOPS ? # fio --filename=/dev/nvme0n1 --name=rw-4M --rw=rw --ioengine=libaio --bs=4M --numjobs=1 --direct=1 --randrepeat=0 --iodepth=1 --runtime=300 --ramp_time=5 --size=100G --group_reporting read : io=46744MB, bw=882011KB/s, iops=215, runt= 54269msec write: io=47028MB, bw=887370KB/s, iops=216, runt= 54269msec # iostat -xk 3 /dev/nvme0n1 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util nvme0n1 0.00 0.00 6805.33 6973.67 871082.67 892629.33 256.00 17.67 1.28 1.67 0.90 0.07 98.33 avg-cpu: %user %nice %system %iowait %steal %idle 0.04 0.00 0.29 0.00 0.00 99.67 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util nvme0n1 0.00 0.00 6688.00 7051.00 856064.00 902528.00 256.00 17.90 1.30 1.72 0.91 0.07 98.30 avg-cpu: %user %nice %system %iowait %steal %idle 0.05 0.00 0.23 0.00 0.00 99.72 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util nvme0n1 0.00 0.00 6709.33 7136.00 858794.67 913408.00 256.00 17.90 1.29 1.71 0.90 0.07 97.90 avg-cpu: %user %nice %system %iowait %steal %idle 0.04 0.00 0.32 0.00 0.00 99.64 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util nvme0n1 0.00 0.00 6880.00 6851.33 880640.00 876970.67 256.00 17.92 1.31 1.71 0.90 0.07 98.47 Many thanks Karan -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
