Hi Jens, if you perform the steps in reverse, i.e. remove the output files, run the old fio (thus have the file generated) the run the freshly built fio (thus reusing the output files) the problem does not show so to me it looks like the accounting lost the plot by having created the files ? HTH =================================================== bgwriter: (g=0): rw=randwrite, bs=4K-4K/4K-4K/4K-4K, ioengine=libaio, iodepth=32 queryA: (g=0): rw=randread, bs=4K-4K/4K-4K/4K-4K, ioengine=mmap, iodepth=1 queryB: (g=0): rw=randread, bs=4K-4K/4K-4K/4K-4K, ioengine=mmap, iodepth=1 bgupdater: (g=0): rw=randrw, bs=4K-4K/4K-4K/4K-4K, ioengine=libaio, iodepth=16 fio-2.0.13 Starting 4 processes bgwriter: Laying out IO file(s) (1 file(s) / 256MB) queryA: Laying out IO file(s) (1 file(s) / 256MB) queryB: Laying out IO file(s) (1 file(s) / 256MB) bgupdater: Laying out IO file(s) (1 file(s) / 64MB) bgwriter: (groupid=0, jobs=1): err= 0: pid=15702: Sat May 18 11:55:16 2013 write: io=16808KB, bw=285457 B/s, iops=69 , runt= 60294msec slat (usec): min=11 , max=888637 , avg=517.21, stdev=19705.69 clat (msec): min=4 , max=2736 , avg=460.42, stdev=366.02 lat (msec): min=4 , max=2736 , avg=460.99, stdev=366.53 bw (KB/s) : min= 0, max= 870, per=73.62%, avg=289.33, stdev=156.06 lat (msec) : 10=1.46%, 20=4.51%, 50=7.62%, 100=5.20%, 250=7.55% lat (msec) : 500=38.29%, 750=18.39%, 1000=7.86%, 2000=9.69%, >=2000=0.17% cpu : usr=0.11%, sys=0.21%, ctx=3726, majf=0, minf=22 IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.2%, 16=0.4%, 32=110.4%, >=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=0/w=4171/d=0, short=r=0/w=0/d=0 queryA: (groupid=0, jobs=1): err= 0: pid=15703: Sat May 18 11:55:16 2013 read : io=1924.0KB, bw=32765 B/s, iops=7 , runt= 60129msec clat (msec): min=1 , max=833 , avg=124.99, stdev=159.31 lat (msec): min=1 , max=833 , avg=125.00, stdev=159.31 bw (KB/s) : min= 0, max= 91, per=18.01%, avg=32.96, stdev=17.98 lat (msec) : 2=0.21%, 10=1.25%, 20=32.43%, 50=21.21%, 100=11.23% lat (msec) : 250=12.89%, 500=17.46%, 750=2.91%, 1000=0.42% cpu : usr=0.02%, sys=0.03%, ctx=520, majf=519, minf=27 IO depths : 1=107.9%, 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 : total=r=481/w=0/d=0, short=r=0/w=0/d=0 queryB: (groupid=0, jobs=1): err= 0: pid=15704: Sat May 18 11:55:16 2013 read : io=2304.0KB, bw=39234 B/s, iops=9 , runt= 60133msec clat (msec): min=3 , max=796 , avg=104.38, stdev=143.78 lat (msec): min=3 , max=796 , avg=104.38, stdev=143.78 bw (KB/s) : min= 0, max= 103, per=21.36%, avg=39.10, stdev=19.61 lat (msec) : 4=0.17%, 10=5.21%, 20=32.81%, 50=25.00%, 100=8.33% lat (msec) : 250=10.42%, 500=15.80%, 750=2.08%, 1000=0.17% cpu : usr=0.02%, sys=0.03%, ctx=630, majf=629, minf=27 IO depths : 1=109.2%, 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 : total=r=576/w=0/d=0, short=r=0/w=0/d=0 bgupdater: (groupid=0, jobs=1): err= 0: pid=15705: Sat May 18 11:55:16 2013 read : io=6852.0KB, bw=116308 B/s, iops=28 , runt= 60326msec slat (usec): min=5 , max=529234 , avg=1241.91, stdev=18167.48 clat (usec): min=5 , max=1280.3K, avg=237605.15, stdev=206635.27 lat (msec): min=2 , max=1280 , avg=238.99, stdev=206.02 bw (KB/s) : min= 0, max= 396, per=64.92%, avg=118.80, stdev=67.68 write: io=6948.0KB, bw=117938 B/s, iops=28 , runt= 60326msec slat (usec): min=8 , max=825689 , avg=2209.25, stdev=27458.48 clat (msec): min=5 , max=1578 , avg=319.33, stdev=261.16 lat (msec): min=5 , max=1578 , avg=321.77, stdev=264.30 bw (KB/s) : min= 15, max= 261, per=30.40%, avg=119.48, stdev=54.96 lat (usec) : 10=0.03%, 50=0.03%, 100=0.06%, 250=0.17%, 500=0.06% lat (msec) : 4=0.15%, 10=1.83%, 20=6.64%, 50=9.34%, 100=10.25% lat (msec) : 250=20.79%, 500=36.36%, 750=10.89%, 1000=1.80%, 2000=2.04% cpu : usr=0.12%, sys=0.17%, ctx=3311, majf=0, minf=22 IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.2%, 16=111.1%, 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=0.1%, 32=0.0%, 64=0.0%, >=64=0.0% issued : total=r=1712/w=1723/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=11080KB, aggrb=183KB/s, minb=31KB/s, maxb=113KB/s, mint=60129msec, maxt=60326msec WRITE: io=23756KB, aggrb=393KB/s, minb=115KB/s, maxb=278KB/s, mint=60294msec, maxt=60326msec Disk stats (read/write): dm-1: ios=3253/10771, merge=0/0, ticks=559883/4212209, in_queue=4777400, util=99.97%, aggrios=3255/10882, aggrmerge=0/0, aggrticks=559956/4221317, aggrin_queue=4781292, aggrutil=99.97% dm-0: ios=3255/10882, merge=0/0, ticks=559956/4221317, in_queue=4781292, util=99.97%, aggrios=3249/7719, aggrmerge=6/3162, aggrticks=554975/3062598, aggrin_queue=3617588, aggrutil=99.97% sda: ios=3249/7719, merge=6/3162, ticks=554975/3062598, in_queue=3617588, util=99.97% ================================================================================ bgwriter: (g=0): rw=randwrite, bs=4K-4K/4K-4K/4K-4K, ioengine=libaio, iodepth=32 queryA: (g=0): rw=randread, bs=4K-4K/4K-4K/4K-4K, ioengine=mmap, iodepth=1 queryB: (g=0): rw=randread, bs=4K-4K/4K-4K/4K-4K, ioengine=mmap, iodepth=1 bgupdater: (g=0): rw=randrw, bs=4K-4K/4K-4K/4K-4K, ioengine=libaio, iodepth=16 fio-2.1-8-gb2c77 Starting 4 processes bgwriter: (groupid=0, jobs=1): err= 0: pid=20441: Sat May 18 11:56:50 2013 write: io=28068KB, bw=476028B/s, iops=115, runt= 60378msec slat (usec): min=9, max=947265, avg=402.78, stdev=14178.87 clat (msec): min=3, max=1635, avg=276.89, stdev=209.31 lat (msec): min=3, max=1635, avg=277.33, stdev=210.07 bw (KB /s): min= 0, max= 1019, per=98.32%, avg=466.03, stdev=150.91 lat (msec) : 4=0.01%, 10=1.83%, 20=4.75%, 50=14.50%, 100=11.21% lat (msec) : 250=5.22%, 500=52.95%, 750=7.29%, 1000=1.95%, 2000=0.73% cpu : usr=0.19%, sys=0.40%, ctx=7319, majf=0, minf=21 IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.2%, 32=109.5%, >=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=0/w=6986/d=0, short=r=0/w=0/d=0 queryA: (groupid=0, jobs=1): err= 0: pid=20442: Sat May 18 11:56:50 2013 read : io=3940.0KB, bw=66862B/s, iops=16, runt= 60341msec clat (msec): min=6, max=762, avg=61.25, stdev=101.94 lat (msec): min=6, max=762, avg=61.25, stdev=101.94 bw (KB /s): min= 0, max= 133, per=45.87%, avg=64.67, stdev=23.10 lat (msec) : 10=2.44%, 20=55.43%, 50=24.77%, 100=1.22%, 250=3.65% lat (msec) : 500=12.18%, 750=0.20%, 1000=0.10% cpu : usr=0.03%, sys=0.06%, ctx=1076, majf=1075, minf=542 IO depths : 1=161.3%, 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 : total=r=985/w=0/d=0, short=r=0/w=0/d=0 queryB: (groupid=0, jobs=1): err= 0: pid=20443: Sat May 18 11:56:50 2013 read : io=3968.0KB, bw=67317B/s, iops=16, runt= 60359msec clat (msec): min=4, max=781, avg=60.83, stdev=102.14 lat (msec): min=4, max=781, avg=60.83, stdev=102.14 bw (KB /s): min= 0, max= 143, per=46.11%, avg=65.02, stdev=23.70 lat (msec) : 10=3.83%, 20=55.04%, 50=23.59%, 100=1.31%, 250=3.23% lat (msec) : 500=12.80%, 750=0.10%, 1000=0.10% cpu : usr=0.05%, sys=0.05%, ctx=1084, majf=1081, minf=654 IO depths : 1=172.1%, 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 : total=r=992/w=0/d=0, short=r=0/w=0/d=0 bgupdater: (groupid=0, jobs=1): err= 0: pid=20444: Sat May 18 11:56:50 2013 read : io=671744B, bw=11149B/s, iops=2, runt= 60249msec slat (usec): min=11, max=2602, avg=66.32, stdev=294.44 clat (msec): min=5, max=759, avg=123.67, stdev=127.15 lat (msec): min=5, max=759, avg=123.74, stdev=127.24 bw (KB /s): min= 3, max= 54, per=9.89%, avg=13.94, stdev=10.61 write: io=577536B, bw=9585B/s, iops=2, runt= 60249msec slat (usec): min=9, max=774595, avg=7006.26, stdev=62617.17 clat (msec): min=32, max=837, avg=275.34, stdev=170.22 lat (msec): min=33, max=900, avg=283.34, stdev=179.59 bw (KB /s): min= 0, max= 16, per=1.93%, avg= 9.13, stdev= 3.62 lat (msec) : 10=2.30%, 20=17.05%, 50=8.52%, 100=6.23%, 250=34.10% lat (msec) : 500=27.87%, 750=2.95%, 1000=0.98% cpu : usr=0.01%, sys=0.02%, ctx=373, majf=0, minf=21 IO depths : 1=109.8%, 2=0.7%, 4=1.3%, 8=2.6%, 16=0.3%, 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 : total=r=164/w=141/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=8564KB, aggrb=141KB/s, minb=10KB/s, maxb=65KB/s, mint=60249msec, maxt=60359msec WRITE: io=28632KB, aggrb=474KB/s, minb=9KB/s, maxb=464KB/s, mint=60249msec, maxt=60378msec Disk stats (read/write): dm-1: ios=2345/12102, merge=0/0, ticks=153582/7496914, in_queue=7659457, util=99.97%, aggrios=2345/12119, aggrmerge=0/0, aggrticks=154444/7512052, aggrin_queue=7666496, aggrutil=99.95% dm-0: ios=2345/12119, merge=0/0, ticks=154444/7512052, in_queue=7666496, util=99.95%, aggrios=2345/8178, aggrmerge=0/3941, aggrticks=153937/2410287, aggrin_queue=2564220, aggrutil=99.95% sda: ios=2345/8178, merge=0/3941, ticks=153937/2410287, in_queue=2564220, util=99.95% -------------------------------------------------- regards, Edoardo Comar WebSphere Application Service Platform for Networks (ASPN) ecomar@xxxxxxxxxx +44 (0)1962 81 5576 IBM UK Ltd, Hursley Park, SO21 2JN Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. 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