> -----Original Message----- > From: Nguyen Viet Dung [mailto:dungnguyenviet@xxxxxxxxx] > Sent: Friday, April 10, 2015 2:23 AM > To: Elliott, Robert (Server Storage) > Cc: fio@xxxxxxxxxxxxxxx > Subject: Re: Need support about value IOPS Which FIO measured > > Dear Elliot, Robert > Thanks you so much for your suggest. That result which i did with fio > follow your suggest is good. > So, i have some parametter on result of fio which i don't understand. > e.g: > Seek time on result of fio > Latency time > Which i can measure performance of my harddisk > I sent for a result which i measure on " 500GB RE4 WD Sata/64MB > WD5003ABYX-01WERA1" (RPM 7200k, support 3.5Gbp/s) > IOPS write 24, read=35. (i think it very low). So do you think about it. > I hope your reply. Thanks A few suggestions: > Run status group 0 (all jobs): > READ: io=500KB, aggrb=254KB/s, minb=120KB/s, maxb=140KB/s, > mint=1885msec, maxt=1962msec > WRITE: io=1128KB, aggrb=593KB/s, minb=97KB/s, maxb=496KB/s, > mint=1885msec, maxt=1901msec > > Disk stats (read/write): > sda: ios=108/280, merge=0/0, ticks=55876/58507, in_queue=144753, > util=94.47% You should run the test a lot longer... this test run only transferred 500+1128 KiB (~ 1 MiB). > lat (usec) : 500=4.46%, 750=1.79%, 1000=2.68% > lat (msec) : 2=4.46%, 10=1.79%, 20=0.89%, 50=8.04%, 100=9.82% > lat (msec) : 250=9.82%, 500=9.82%, 750=16.96%, 1000=0.89%, 2000=28.57% What those mean is: * 4+1+2 = 7% of the time, the latency was 1 ms or less. These are probably read cache hits * ... * 8+9+9+9+16 = 51% of the time, the latencies ranged from 50 ms to 750 ms. These are normal accesses. * 28% of the time, the latencies were 1 to 2 s These are either from the drive doing some background activity, or your queue depth is too high, the I/Os are just stacking up somewhere, or even that the drive was spundown and took a while to resume. All of those suggest iodepth=32 is too high for this drive; you should be seeing single or double digit ms latencies dominate. Results may change with a longer run time. ��.n��������+%������w��{.n�������^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�
