I've done some more testing, comparing RAID 1 HDD with RAID 1 HDD + an SSD overlay (using lvm-cache). I'm now using 'fio', with the following job file: [virt] ioengine=libaio iodepth=4 rw=randrw bs=64k direct=1 size=1g numjobs=4 I'm still seeing almost no benefit from LVM cache. It's about 4% faster than the underlying, slow HDDs. See attached runs. The SSD LV is 200 GB and the underlying LV is 800 GB, so I would expect there is plenty of space to cache things in the SSD during the test. For comparison, the fio tests runs about 11 times faster on the SSD. Any ideas? Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v
virt: (g=0): rw=randrw, bs=64K-64K/64K-64K/64K-64K, ioengine=libaio, iodepth=4 ... virt: (g=0): rw=randrw, bs=64K-64K/64K-64K/64K-64K, ioengine=libaio, iodepth=4 fio-2.1.2 Starting 4 processes virt: Laying out IO file(s) (1 file(s) / 1024MB) virt: Laying out IO file(s) (1 file(s) / 1024MB) virt: Laying out IO file(s) (1 file(s) / 1024MB) virt: Laying out IO file(s) (1 file(s) / 1024MB) virt: (groupid=0, jobs=1): err= 0: pid=2195: Wed May 28 22:12:50 2014 read : io=523520KB, bw=2600.4KB/s, iops=40, runt=201329msec slat (usec): min=23, max=24586, avg=65.89, stdev=306.38 clat (usec): min=305, max=1765.7K, avg=84912.67, stdev=124153.30 lat (usec): min=367, max=1765.8K, avg=84979.16, stdev=124150.29 clat percentiles (usec): | 1.00th=[ 780], 5.00th=[ 6944], 10.00th=[ 9536], 20.00th=[14144], | 30.00th=[19840], 40.00th=[28032], 50.00th=[40704], 60.00th=[57600], | 70.00th=[82432], 80.00th=[125440], 90.00th=[209920], 95.00th=[309248], | 99.00th=[593920], 99.50th=[790528], 99.90th=[1204224], 99.95th=[1286144], | 99.99th=[1761280] bw (KB /s): min= 82, max=12416, per=25.85%, avg=2688.32, stdev=1545.40 write: io=525056KB, bw=2607.1KB/s, iops=40, runt=201329msec slat (usec): min=31, max=140675, avg=132.77, stdev=1945.34 clat (usec): min=346, max=1355.5K, avg=13280.27, stdev=57149.27 lat (usec): min=404, max=1355.6K, avg=13413.69, stdev=57202.63 clat percentiles (usec): | 1.00th=[ 358], 5.00th=[ 374], 10.00th=[ 434], 20.00th=[ 446], | 30.00th=[ 644], 40.00th=[ 852], 50.00th=[ 1272], 60.00th=[ 1320], | 70.00th=[ 1496], 80.00th=[ 5728], 90.00th=[18048], 95.00th=[63232], | 99.00th=[257024], 99.50th=[382976], 99.90th=[831488], 99.95th=[946176], | 99.99th=[1351680] bw (KB /s): min= 121, max=10709, per=25.96%, avg=2708.14, stdev=1769.64 lat (usec) : 500=12.91%, 750=6.04%, 1000=3.25% lat (msec) : 2=16.32%, 4=1.65%, 10=7.59%, 20=12.91%, 50=14.75% lat (msec) : 100=9.90%, 250=10.51%, 500=3.19%, 750=0.66%, 1000=0.20% lat (msec) : 2000=0.13% cpu : usr=0.11%, sys=0.54%, ctx=16504, majf=0, minf=23 IO depths : 1=0.1%, 2=0.1%, 4=100.0%, 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=8180/w=8204/d=0, short=r=0/w=0/d=0 virt: (groupid=0, jobs=1): err= 0: pid=2196: Wed May 28 22:12:50 2014 read : io=523520KB, bw=2947.6KB/s, iops=46, runt=177615msec slat (usec): min=24, max=59936, avg=81.73, stdev=987.31 clat (usec): min=149, max=1054.1K, avg=74995.11, stdev=93418.23 lat (usec): min=369, max=1054.2K, avg=75077.47, stdev=93411.06 clat percentiles (msec): | 1.00th=[ 5], 5.00th=[ 8], 10.00th=[ 10], 20.00th=[ 16], | 30.00th=[ 22], 40.00th=[ 31], 50.00th=[ 42], 60.00th=[ 57], | 70.00th=[ 80], 80.00th=[ 116], 90.00th=[ 180], 95.00th=[ 260], | 99.00th=[ 437], 99.50th=[ 529], 99.90th=[ 840], 99.95th=[ 979], | 99.99th=[ 1057] bw (KB /s): min= 113, max= 6898, per=29.26%, avg=3043.36, stdev=1217.82 write: io=525056KB, bw=2956.2KB/s, iops=46, runt=177615msec slat (usec): min=33, max=140655, avg=128.77, stdev=2069.57 clat (usec): min=258, max=1000.6K, avg=11590.37, stdev=57029.08 lat (usec): min=403, max=1000.7K, avg=11719.76, stdev=57077.03 clat percentiles (usec): | 1.00th=[ 362], 5.00th=[ 378], 10.00th=[ 434], 20.00th=[ 446], | 30.00th=[ 612], 40.00th=[ 748], 50.00th=[ 1224], 60.00th=[ 1304], | 70.00th=[ 1352], 80.00th=[ 1528], 90.00th=[ 7776], 95.00th=[55040], | 99.00th=[244736], 99.50th=[362496], 99.90th=[913408], 99.95th=[929792], | 99.99th=[1003520] bw (KB /s): min= 140, max= 7409, per=29.16%, avg=3042.19, stdev=1466.35 lat (usec) : 250=0.01%, 500=13.49%, 750=6.57%, 1000=3.19% lat (msec) : 2=19.84%, 4=1.70%, 10=5.92%, 20=9.95%, 50=14.89% lat (msec) : 100=10.81%, 250=10.45%, 500=2.73%, 750=0.31%, 1000=0.13% lat (msec) : 2000=0.02% cpu : usr=0.14%, sys=0.59%, ctx=16858, majf=0, minf=23 IO depths : 1=0.1%, 2=0.1%, 4=100.0%, 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=8180/w=8204/d=0, short=r=0/w=0/d=0 virt: (groupid=0, jobs=1): err= 0: pid=2197: Wed May 28 22:12:50 2014 read : io=523520KB, bw=2923.2KB/s, iops=45, runt=179092msec slat (usec): min=20, max=99838, avg=91.84, stdev=1411.97 clat (usec): min=160, max=1512.4K, avg=75755.06, stdev=105522.71 lat (usec): min=382, max=1512.9K, avg=75847.54, stdev=105514.14 clat percentiles (msec): | 1.00th=[ 5], 5.00th=[ 8], 10.00th=[ 10], 20.00th=[ 15], | 30.00th=[ 21], 40.00th=[ 29], 50.00th=[ 40], 60.00th=[ 56], | 70.00th=[ 76], 80.00th=[ 112], 90.00th=[ 186], 95.00th=[ 269], | 99.00th=[ 469], 99.50th=[ 586], 99.90th=[ 1156], 99.95th=[ 1287], | 99.99th=[ 1516] bw (KB /s): min= 124, max= 6144, per=29.37%, avg=3055.29, stdev=1223.87 write: io=525056KB, bw=2931.8KB/s, iops=45, runt=179092msec slat (usec): min=35, max=140660, avg=114.41, stdev=1768.12 clat (usec): min=345, max=1441.6K, avg=11547.93, stdev=62451.29 lat (usec): min=415, max=1441.7K, avg=11663.01, stdev=62476.14 clat percentiles (usec): | 1.00th=[ 362], 5.00th=[ 378], 10.00th=[ 434], 20.00th=[ 446], | 30.00th=[ 596], 40.00th=[ 756], 50.00th=[ 1224], 60.00th=[ 1304], | 70.00th=[ 1352], 80.00th=[ 1544], 90.00th=[ 8896], 95.00th=[37632], | 99.00th=[232448], 99.50th=[350208], 99.90th=[995328], 99.95th=[1044480], | 99.99th=[1433600] bw (KB /s): min= 80, max= 9325, per=29.37%, avg=3063.24, stdev=1532.25 lat (usec) : 250=0.01%, 500=13.56%, 750=6.50%, 1000=3.08% lat (msec) : 2=19.73%, 4=1.62%, 10=6.32%, 20=10.52%, 50=14.89% lat (msec) : 100=10.77%, 250=9.75%, 500=2.72%, 750=0.27%, 1000=0.13% lat (msec) : 2000=0.14% cpu : usr=0.14%, sys=0.59%, ctx=16985, majf=0, minf=23 IO depths : 1=0.1%, 2=0.1%, 4=100.0%, 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=8180/w=8204/d=0, short=r=0/w=0/d=0 virt: (groupid=0, jobs=1): err= 0: pid=2198: Wed May 28 22:12:50 2014 read : io=523520KB, bw=2629.9KB/s, iops=41, runt=199069msec slat (usec): min=25, max=99063, avg=89.77, stdev=1365.24 clat (usec): min=112, max=1392.1K, avg=83373.43, stdev=118987.34 lat (usec): min=369, max=1392.1K, avg=83463.84, stdev=118977.09 clat percentiles (msec): | 1.00th=[ 3], 5.00th=[ 7], 10.00th=[ 10], 20.00th=[ 15], | 30.00th=[ 21], 40.00th=[ 28], 50.00th=[ 40], 60.00th=[ 57], | 70.00th=[ 81], 80.00th=[ 122], 90.00th=[ 206], 95.00th=[ 310], | 99.00th=[ 603], 99.50th=[ 734], 99.90th=[ 979], 99.95th=[ 1156], | 99.99th=[ 1401] bw (KB /s): min= 64, max= 9708, per=26.35%, avg=2740.70, stdev=1540.11 write: io=525056KB, bw=2637.6KB/s, iops=41, runt=199069msec slat (usec): min=38, max=140657, avg=121.47, stdev=1860.80 clat (usec): min=349, max=1002.9K, avg=13698.39, stdev=66153.66 lat (usec): min=405, max=1002.9K, avg=13820.49, stdev=66192.16 clat percentiles (usec): | 1.00th=[ 362], 5.00th=[ 378], 10.00th=[ 434], 20.00th=[ 446], | 30.00th=[ 652], 40.00th=[ 876], 50.00th=[ 1272], 60.00th=[ 1320], | 70.00th=[ 1448], 80.00th=[ 2992], 90.00th=[15552], 95.00th=[36096], | 99.00th=[321536], 99.50th=[489472], 99.90th=[962560], 99.95th=[995328], | 99.99th=[1003520] bw (KB /s): min= 71, max= 9836, per=26.41%, avg=2755.14, stdev=1757.17 lat (usec) : 250=0.02%, 500=12.84%, 750=5.83%, 1000=3.12% lat (msec) : 2=17.58%, 4=1.73%, 10=7.50%, 20=12.41%, 50=14.97% lat (msec) : 100=9.86%, 250=9.86%, 500=3.19%, 750=0.78%, 1000=0.25% lat (msec) : 2000=0.06% cpu : usr=0.12%, sys=0.53%, ctx=16540, majf=0, minf=22 IO depths : 1=0.1%, 2=0.1%, 4=100.0%, 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=8180/w=8204/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=2045.0MB, aggrb=10401KB/s, minb=2600KB/s, maxb=2947KB/s, mint=177615msec, maxt=201329msec WRITE: io=2051.0MB, aggrb=10431KB/s, minb=2607KB/s, maxb=2956KB/s, mint=177615msec, maxt=201329msec Disk stats (read/write): dm-0: ios=32841/33299, merge=0/0, ticks=2623746/506809, in_queue=3130698, util=100.00%, aggrios=32855/33392, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md127: ios=32855/33392, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=16426/33225, aggrmerge=1/168, aggrticks=1311820/306619, aggrin_queue=1618332, aggrutil=98.91% sda: ios=8494/33223, merge=0/171, ticks=464540/232964, in_queue=697442, util=96.18% sdb: ios=24359/33228, merge=2/166, ticks=2159100/380274, in_queue=2539222, util=98.91%
virt: (g=0): rw=randrw, bs=64K-64K/64K-64K/64K-64K, ioengine=libaio, iodepth=4 ... virt: (g=0): rw=randrw, bs=64K-64K/64K-64K/64K-64K, ioengine=libaio, iodepth=4 fio-2.1.2 Starting 4 processes virt: Laying out IO file(s) (1 file(s) / 1024MB) virt: Laying out IO file(s) (1 file(s) / 1024MB) virt: Laying out IO file(s) (1 file(s) / 1024MB) virt: Laying out IO file(s) (1 file(s) / 1024MB) virt: (groupid=0, jobs=1): err= 0: pid=1643: Thu May 29 14:44:39 2014 read : io=523520KB, bw=2721.8KB/s, iops=42, runt=192348msec slat (usec): min=36, max=11159, avg=79.21, stdev=140.35 clat (usec): min=305, max=1346.1K, avg=82931.26, stdev=118358.55 lat (usec): min=383, max=1347.8K, avg=83011.13, stdev=118357.33 clat percentiles (usec): | 1.00th=[ 556], 5.00th=[ 6368], 10.00th=[ 8896], 20.00th=[13632], | 30.00th=[18816], 40.00th=[26496], 50.00th=[38144], 60.00th=[55552], | 70.00th=[81408], 80.00th=[125440], 90.00th=[211968], 95.00th=[313344], | 99.00th=[561152], 99.50th=[708608], 99.90th=[1056768], 99.95th=[1138688], | 99.99th=[1351680] bw (KB /s): min= 64, max=13714, per=25.99%, avg=2828.82, stdev=1614.75 write: io=525056KB, bw=2729.8KB/s, iops=42, runt=192348msec slat (usec): min=40, max=120228, avg=113.58, stdev=1327.58 clat (usec): min=345, max=1401.6K, avg=10882.68, stdev=66932.84 lat (usec): min=428, max=1401.7K, avg=10996.89, stdev=66947.30 clat percentiles (usec): | 1.00th=[ 358], 5.00th=[ 366], 10.00th=[ 386], 20.00th=[ 442], | 30.00th=[ 612], 40.00th=[ 812], 50.00th=[ 1240], 60.00th=[ 1304], | 70.00th=[ 1448], 80.00th=[ 2960], 90.00th=[12736], 95.00th=[23168], | 99.00th=[259072], 99.50th=[403456], 99.90th=[995328], 99.95th=[1286144], | 99.99th=[1400832] bw (KB /s): min= 105, max=13079, per=26.20%, avg=2860.76, stdev=1798.77 lat (usec) : 500=13.62%, 750=6.18%, 1000=2.75% lat (msec) : 2=17.00%, 4=1.83%, 10=8.55%, 20=12.82%, 50=14.40% lat (msec) : 100=9.28%, 250=9.26%, 500=3.45%, 750=0.50%, 1000=0.23% lat (msec) : 2000=0.13% cpu : usr=0.13%, sys=0.69%, ctx=16575, majf=0, minf=23 IO depths : 1=0.1%, 2=0.1%, 4=100.0%, 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=8180/w=8204/d=0, short=r=0/w=0/d=0 virt: (groupid=0, jobs=1): err= 0: pid=1644: Thu May 29 14:44:39 2014 read : io=523520KB, bw=3056.4KB/s, iops=47, runt=171287msec slat (usec): min=34, max=166, avg=77.72, stdev=12.41 clat (usec): min=314, max=1179.1K, avg=76362.24, stdev=95270.37 lat (usec): min=386, max=1180.8K, avg=76440.60, stdev=95269.97 clat percentiles (msec): | 1.00th=[ 5], 5.00th=[ 8], 10.00th=[ 10], 20.00th=[ 16], | 30.00th=[ 23], 40.00th=[ 31], 50.00th=[ 42], 60.00th=[ 58], | 70.00th=[ 80], 80.00th=[ 118], 90.00th=[ 186], 95.00th=[ 262], | 99.00th=[ 457], 99.50th=[ 570], 99.90th=[ 791], 99.95th=[ 906], | 99.99th=[ 1188] bw (KB /s): min= 237, max= 6259, per=28.43%, avg=3094.94, stdev=1094.43 write: io=525056KB, bw=3065.4KB/s, iops=47, runt=171287msec slat (usec): min=47, max=120139, avg=115.02, stdev=1329.52 clat (usec): min=343, max=958790, avg=7162.31, stdev=39237.72 lat (usec): min=422, max=958895, avg=7277.98, stdev=39265.48 clat percentiles (usec): | 1.00th=[ 358], 5.00th=[ 370], 10.00th=[ 386], 20.00th=[ 442], | 30.00th=[ 588], 40.00th=[ 740], 50.00th=[ 1192], 60.00th=[ 1288], | 70.00th=[ 1320], 80.00th=[ 1496], 90.00th=[ 3216], 95.00th=[15552], | 99.00th=[183296], 99.50th=[301056], 99.90th=[514048], 99.95th=[610304], | 99.99th=[962560] bw (KB /s): min= 100, max= 7418, per=28.37%, avg=3097.42, stdev=1395.25 lat (usec) : 500=13.75%, 750=6.58%, 1000=3.16% lat (msec) : 2=20.43%, 4=1.64%, 10=6.06%, 20=9.94%, 50=14.88% lat (msec) : 100=10.52%, 250=9.92%, 500=2.67%, 750=0.35%, 1000=0.06% lat (msec) : 2000=0.01% cpu : usr=0.14%, sys=0.79%, ctx=16933, majf=0, minf=23 IO depths : 1=0.1%, 2=0.1%, 4=100.0%, 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=8180/w=8204/d=0, short=r=0/w=0/d=0 virt: (groupid=0, jobs=1): err= 0: pid=1645: Thu May 29 14:44:39 2014 read : io=523520KB, bw=3097.5KB/s, iops=48, runt=169019msec slat (usec): min=36, max=141, avg=77.24, stdev=12.48 clat (usec): min=311, max=1577.6K, avg=74149.52, stdev=97313.65 lat (usec): min=376, max=1577.6K, avg=74227.41, stdev=97313.32 clat percentiles (msec): | 1.00th=[ 5], 5.00th=[ 8], 10.00th=[ 10], 20.00th=[ 15], | 30.00th=[ 22], 40.00th=[ 30], 50.00th=[ 42], 60.00th=[ 56], | 70.00th=[ 77], 80.00th=[ 112], 90.00th=[ 176], 95.00th=[ 251], | 99.00th=[ 453], 99.50th=[ 578], 99.90th=[ 947], 99.95th=[ 1254], | 99.99th=[ 1582] bw (KB /s): min= 62, max= 7492, per=29.37%, avg=3197.36, stdev=1186.93 write: io=525056KB, bw=3106.6KB/s, iops=48, runt=169019msec slat (usec): min=47, max=120168, avg=112.54, stdev=1325.71 clat (usec): min=335, max=1474.2K, avg=8254.87, stdev=57083.94 lat (usec): min=416, max=1474.3K, avg=8368.05, stdev=57098.21 clat percentiles (usec): | 1.00th=[ 358], 5.00th=[ 366], 10.00th=[ 386], 20.00th=[ 442], | 30.00th=[ 564], 40.00th=[ 724], 50.00th=[ 1176], 60.00th=[ 1272], | 70.00th=[ 1320], 80.00th=[ 1464], 90.00th=[ 2224], 95.00th=[13504], | 99.00th=[185344], 99.50th=[321536], 99.90th=[1019904], 99.95th=[1073152], | 99.99th=[1466368] bw (KB /s): min= 109, max= 8172, per=29.43%, avg=3213.21, stdev=1535.62 lat (usec) : 500=14.15%, 750=6.58%, 1000=3.03% lat (msec) : 2=20.82%, 4=1.48%, 10=6.24%, 20=9.75%, 50=14.67% lat (msec) : 100=10.94%, 250=9.46%, 500=2.37%, 750=0.34%, 1000=0.07% lat (msec) : 2000=0.10% cpu : usr=0.13%, sys=0.81%, ctx=16936, majf=0, minf=23 IO depths : 1=0.1%, 2=0.1%, 4=100.0%, 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=8180/w=8204/d=0, short=r=0/w=0/d=0 virt: (groupid=0, jobs=1): err= 0: pid=1646: Thu May 29 14:44:39 2014 read : io=523520KB, bw=2773.6KB/s, iops=43, runt=188788msec slat (usec): min=23, max=2618, avg=77.53, stdev=31.29 clat (usec): min=309, max=1755.5K, avg=82247.61, stdev=119257.63 lat (usec): min=356, max=1755.6K, avg=82325.78, stdev=119257.35 clat percentiles (msec): | 1.00th=[ 4], 5.00th=[ 7], 10.00th=[ 10], 20.00th=[ 14], | 30.00th=[ 20], 40.00th=[ 27], 50.00th=[ 38], 60.00th=[ 55], | 70.00th=[ 81], 80.00th=[ 122], 90.00th=[ 212], 95.00th=[ 306], | 99.00th=[ 578], 99.50th=[ 750], 99.90th=[ 988], 99.95th=[ 1106], | 99.99th=[ 1762] bw (KB /s): min= 122, max= 9325, per=26.30%, avg=2863.03, stdev=1442.98 write: io=525056KB, bw=2781.2KB/s, iops=43, runt=188788msec slat (usec): min=44, max=120232, avg=112.99, stdev=1326.51 clat (usec): min=346, max=1033.4K, avg=9830.80, stdev=52064.46 lat (usec): min=421, max=1033.5K, avg=9944.42, stdev=52084.32 clat percentiles (usec): | 1.00th=[ 362], 5.00th=[ 370], 10.00th=[ 386], 20.00th=[ 446], | 30.00th=[ 588], 40.00th=[ 788], 50.00th=[ 1240], 60.00th=[ 1304], | 70.00th=[ 1416], 80.00th=[ 1976], 90.00th=[12736], 95.00th=[23424], | 99.00th=[244736], 99.50th=[333824], 99.90th=[937984], 99.95th=[954368], | 99.99th=[1036288] bw (KB /s): min= 100, max= 8694, per=26.24%, avg=2865.37, stdev=1678.69 lat (usec) : 500=13.65%, 750=6.05%, 1000=2.78% lat (msec) : 2=18.05%, 4=1.64%, 10=7.68%, 20=12.79%, 50=14.66% lat (msec) : 100=9.39%, 250=9.17%, 500=3.31%, 750=0.51%, 1000=0.24% lat (msec) : 2000=0.07% cpu : usr=0.13%, sys=0.70%, ctx=16629, majf=0, minf=22 IO depths : 1=0.1%, 2=0.1%, 4=100.0%, 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=8180/w=8204/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=2045.0MB, aggrb=10886KB/s, minb=2721KB/s, maxb=3097KB/s, mint=169019msec, maxt=192348msec WRITE: io=2051.0MB, aggrb=10918KB/s, minb=2729KB/s, maxb=3106KB/s, mint=169019msec, maxt=192348msec Disk stats (read/write): dm-3: ios=32687/32957, merge=0/0, ticks=2580936/388295, in_queue=2969480, util=100.00%, aggrios=10910/11025, aggrmerge=0/0, aggrticks=860321/160031, aggrin_queue=1020354, aggrutil=100.00% dm-0: ios=5/44, merge=0/0, ticks=10/85, in_queue=95, util=0.05%, aggrios=11/50, aggrmerge=0/2, aggrticks=11/94, aggrin_queue=105, aggrutil=0.05% sdc: ios=11/50, merge=0/2, ticks=11/94, in_queue=105, util=0.05% dm-1: ios=6/8, merge=0/0, ticks=1/9, in_queue=10, util=0.01% dm-2: ios=32721/33023, merge=0/0, ticks=2580952/479999, in_queue=3060959, util=100.00%, aggrios=32721/33023, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md127: ios=32721/33023, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=16360/32937, aggrmerge=0/87, aggrticks=1290283/255548, aggrin_queue=1545711, aggrutil=99.71% sda: ios=8101/32937, merge=1/88, ticks=402681/125603, in_queue=528232, util=96.21% sdb: ios=24619/32938, merge=0/87, ticks=2177886/385493, in_queue=2563190, util=99.71%
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