Hi all, I don't know exactly which mailinglists to use for this one so I hope i used the right ones. I did some performance testing on a new system and found out some things I couldn't explain or didn't expect. At the end are some questions I hope to get answered to explain the tings i'm seeing in the test. First of all a description of my setup. The server is a 36 bay 3,5" supermicro chassis filled with 36x 2TB SATA 7200 RPM disks. I use a single SSD as OS disk (Debian Squeeze stable) connected to the motherboard SATA port1. The data disks are connected to a LSI 9211-8i controller in IT mode (non-raid). Once booted I created 3 raid6 MD devices of 10 disks each (16TB netto each) with 6 global hotspares in the same sparegroup. All MD devices have a chunk size of 64KB I started testing using fio (2.0.4) I used a bandwidth random read test I found on the Fusion IO website. after every test i ran: sync; echo 3 >/proc/sys/vm/drop_caches; The first test was on a single md device. fio --name=test1 --ioengine=sync --direct=1 --rw=randread --bs=1m --runtime=10 --filename=/dev/md0 --iodepth=1 --invalidate=1 (check the attachments for the full fio output, i'll only post the (in my eyes) important snippets). read : io=518144KB, bw=51726KB/s, iops=50 , runt= 10017msec Disk stats (read/write): md0: ios=8000/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=674/0, aggrmerge=0/0, aggrticks=10183/0, aggrin_queue=10183, aggrutil=77.97% sdc: ios=830/0, merge=0/0, ticks=12584/0, in_queue=12584, util=63.15% So the IOPS for this test is 50. Bandwidth is around 50MB/s (50 iops x 1m blocksize) The md0 device gets 8000 total IO's. Divided by 10 seconds this is 800 IOPS (So the 1MB blocksize go to the disks in 64KB blocks because the chunksize of the md is 64KB. 800 IOPS is 16x the reported 50 IOPS above = 1MB / 16 = 64KB) The md0 gets 800 IOPS in 64KB blocks and this relates to 50 IOPS in 1MB blocks Each disks gets around 800 total IO's, divided by 10 is 80 IOPS, which is slightly lower than the number you would expect from a 7200 RPM SATA disk (around 110 IOPS) For the next test I introduced LVM (create a VG with md0 as PV, then created a 2TB LV on it) fio --name=test2 --ioengine=sync --direct=1 --rw=randread --bs=1m --runtime=10 --filename=/dev/dm-0 --iodepth=1 --invalidate=1 read : io=705536KB, bw=70476KB/s, iops=68 , runt= 10011msec Disk stats (read/write): dm-0: ios=10880/0, merge=0/0, ticks=114720/0, in_queue=114784, util=98.86%, aggrios=11024/0, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md0: ios=11024/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=918/0, aggrmerge=0/0, aggrticks=9684/0, aggrin_queue=9684, aggrutil=74.05% sdc: ios=1106/0, merge=0/0, ticks=11668/0, in_queue=11668, util=72.07% Now the IOPS went from 50 to around 70 and the bandwidth from 50MB/s to 70MB/s which is not what I expected since I introduced another layer and the performance increases. The dm-0 device gets 10880 total IO's. Divided by 10 seconds this is 1088 IOPS (So the 1MB blocksize go to the disks in 64KB blocks because the chunksize of the md is 64KB. 1088 IOPS is 16x the reported 68 IOPS above = 1MB / 16 = 64KB) Each disk now does around 110 IOPS which is what you would expect for these type of disks. For the next test I wanted to see if i could double the performance by striping an LV over 2 md's (so instead of using 10 disks/spindles, use 20 disks/spindles) So i added md1 to the VG as PV. Created a fresh LV striped across the two PV's using a 64KB stripe size and ran the test again. fio --name=test3 --ioengine=sync --direct=1 --rw=randread --bs=1m --runtime=10 --filename=/dev/dm-0 --iodepth=1 --invalidate=1 Now things are getting interesting: read : io=769024KB, bw=76849KB/s, iops=75 , runt= 10007msec Disk stats (read/write): dm-0: ios=190464/0, merge=0/0, ticks=1695940/0, in_queue=1695940, util=98.03%, aggrios=96128/0, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md0: ios=96128/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=502/0, aggrmerge=7508/0, aggrticks=4517/0, aggrin_queue=4517, aggrutil=55.56% sdc: ios=583/0, merge=8745/0, ticks=5100/0, in_queue=5100, util=50.53% md1: ios=96128/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=503/0, aggrmerge=7507/0, aggrticks=4469/0, aggrin_queue=4469, aggrutil=55.77% Now the total IO's in 10 seconds are 16x larger than before. 190464 / 10 = 19046,4 / 16 = 1190,4 /16 = the reported 75 IOPS above. So the 64KB blocks seem to be split into 4KB blocks (64 / 16 = 4) which results in a way larger total IO's. The IO's per disk seem to be in 64KB blocks still only now with a large MERGE figure besides it. (Now 4KB blocks are merged into 64KB blocks?) The performance does not double but stays the same as with 1 MD set only the total IO's are spread among the MD's. Each disk now does around 60 IOPS! I still wanted to see if I could double the performance and thought it might have something to do with LVM striping so i ditched LVM and created a RAID0 (md6) over md0 and md1 with a chunk size of 64KB again. fio --name=test4 --ioengine=sync --direct=1 --rw=randread --bs=1m --runtime=10 --filename=/dev/md6 --iodepth=1 --invalidate=1 Same story as for LVM striping only the performance is even worse: read : io=462848KB, bw=46257KB/s, iops=45 , runt= 10006msec md6: ios=114432/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=57856/0, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md0: ios=57856/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=302/0, aggrmerge=4519/0, aggrticks=4782/0, aggrin_queue=4782, aggrutil=59.46% sdc: ios=360/0, merge=5368/0, ticks=5676/0, in_queue=5676, util=55.89% Performance is spread among the md's and each disk only does 36 IOPS now! As a final test I wanted to know how 20 disks in a single raid6 performed so i created 1 md out of 20 disks (still using a 64KB chunk size). fio --name=test5 --ioengine=sync --direct=1 --rw=randread --bs=1m --runtime=10 --filename=/dev/md0 --iodepth=1 --invalidate=1 read : io=504832KB, bw=50453KB/s, iops=49 , runt= 10006msec md0: ios=7808/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=328/0, aggrmerge=0/0, aggrticks=4925/0, aggrin_queue=4925, aggrutil=61.63% sdb: ios=395/0, merge=0/0, ticks=5652/0, in_queue=5652, util=56.00% 50 IOPS total (1MB blocks) and each disk is doing around 40 IOPS (64KB blocks) And adding LVM (VG over md0 and a 2TB LV) to that fio --name=test6 --ioengine=sync --direct=1 --rw=randread --bs=1m --runtime=10 --filename=/dev/md0 --iodepth=1 --invalidate=1 read : io=801792KB, bw=80163KB/s, iops=78 , runt= 10002msec dm-0: ios=12416/0, merge=0/0, ticks=108252/0, in_queue=108252, util=98.82%, aggrios=12528/0, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md0: ios=12528/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=522/0, aggrmerge=0/0, aggrticks=4547/0, aggrin_queue=4547, aggrutil=55.80% sdb: ios=637/0, merge=0/0, ticks=5492/0, in_queue=5492, util=54.41% 78 IOPS total (1MB blocks) and each disk is doing around 64 IOPS (64KB blocks) I wanted to rule out the LSI controller as a bottleneck so I installed a second LSI 9211-8i and connected 10 disks to controller 1 and 10 disks to controller 2 and created a 20 disk raid6 with these disks. The results (test7 and test8) are pretty much the same as with using 1 controller. So my questions are: 1) Am I overlooking/not understanding something obvious why I can't improve performance on the system? 2) Why are the LVM tests performing better as opposed to only using MD(s)? 3) Why is the performance in test3 split between the two PV's and not aggregated? Bottleneck somewhere, and if so how can I check which is it? 4) Why are the IO's suddenly split into 4KB blocks when using striping/raid0? All chunk/block/stripe sizes are 64KB. 5) Any recommendations how to improve performance with this configuration and not limited at the performance of 10 disks? Kind regards, Caspar Smit
test1: (g=0): rw=randread, bs=1M-1M/1M-1M, ioengine=sync, iodepth=1 fio 2.0.4 Starting 1 process test1: (groupid=0, jobs=1): err= 0: pid=12218 read : io=518144KB, bw=51726KB/s, iops=50 , runt= 10017msec clat (usec): min=694 , max=268167 , avg=19790.64, stdev=13161.97 lat (usec): min=694 , max=268167 , avg=19790.91, stdev=13161.97 clat percentiles (usec): | 1.00th=[ 732], 5.00th=[11328], 10.00th=[14784], 20.00th=[16512], | 30.00th=[17536], 40.00th=[18560], 50.00th=[19328], 60.00th=[20096], | 70.00th=[21120], 80.00th=[22144], 90.00th=[23936], 95.00th=[25216], | 99.00th=[56064], 99.50th=[69120], 99.90th=[268288] bw (KB/s) : min=22304, max=66316, per=99.84%, avg=51642.68, stdev=7977.53 lat (usec) : 750=2.37%, 1000=1.78% lat (msec) : 2=0.20%, 20=54.15%, 50=40.12%, 100=1.19%, 500=0.20% cpu : usr=0.00%, sys=0.72%, ctx=514, majf=0, minf=284 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 : total=r=506/w=0/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=518144KB, aggrb=51726KB/s, minb=52967KB/s, maxb=52967KB/s, mint=10017msec, maxt=10017msec Disk stats (read/write): md0: ios=8000/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=674/0, aggrmerge=0/0, aggrticks=10183/0, aggrin_queue=10183, aggrutil=77.97% sdc: ios=830/0, merge=0/0, ticks=12584/0, in_queue=12584, util=63.15% sdd: ios=818/0, merge=0/0, ticks=12480/0, in_queue=12480, util=75.60% sde: ios=806/0, merge=0/0, ticks=13000/0, in_queue=13000, util=65.24% sdf: ios=816/0, merge=0/0, ticks=12228/0, in_queue=12228, util=74.93% sdg: ios=826/0, merge=0/0, ticks=12412/0, in_queue=12412, util=62.04% sdh: ios=812/0, merge=0/0, ticks=12092/0, in_queue=12092, util=75.72% sdi: ios=798/0, merge=0/0, ticks=11916/0, in_queue=11916, util=59.83% sdj: ios=793/0, merge=0/0, ticks=12160/0, in_queue=12160, util=77.97% sdk: ios=788/0, merge=0/0, ticks=11140/0, in_queue=11140, util=55.88% sdaf: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdag: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdb: ios=809/0, merge=0/0, ticks=12188/0, in_queue=12188, util=74.93% ---- test2: (g=0): rw=randread, bs=1M-1M/1M-1M, ioengine=sync, iodepth=1 fio 2.0.4 Starting 1 process test2: (groupid=0, jobs=1): err= 0: pid=15396 read : io=705536KB, bw=70476KB/s, iops=68 , runt= 10011msec clat (msec): min=9 , max=264 , avg=14.52, stdev=12.99 lat (msec): min=9 , max=264 , avg=14.52, stdev=12.99 clat percentiles (msec): | 1.00th=[ 11], 5.00th=[ 12], 10.00th=[ 12], 20.00th=[ 13], | 30.00th=[ 14], 40.00th=[ 14], 50.00th=[ 14], 60.00th=[ 15], | 70.00th=[ 15], 80.00th=[ 16], 90.00th=[ 16], 95.00th=[ 17], | 99.00th=[ 20], 99.50th=[ 24], 99.90th=[ 265] bw (KB/s) : min= 4055, max=75776, per=100.00%, avg=70507.00, stdev=16129.06 lat (msec) : 10=0.58%, 20=98.55%, 50=0.58%, 250=0.15%, 500=0.15% cpu : usr=0.00%, sys=1.28%, ctx=708, majf=0, minf=284 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 : total=r=689/w=0/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=705536KB, aggrb=70476KB/s, minb=72167KB/s, maxb=72167KB/s, mint=10011msec, maxt=10011msec Disk stats (read/write): dm-0: ios=10880/0, merge=0/0, ticks=114720/0, in_queue=114784, util=98.86%, aggrios=11024/0, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md0: ios=11024/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=918/0, aggrmerge=0/0, aggrticks=9684/0, aggrin_queue=9684, aggrutil=74.05% sdc: ios=1106/0, merge=0/0, ticks=11668/0, in_queue=11668, util=72.07% sdd: ios=1100/0, merge=0/0, ticks=11700/0, in_queue=11700, util=58.90% sde: ios=1105/0, merge=0/0, ticks=12012/0, in_queue=12012, util=74.05% sdf: ios=1110/0, merge=0/0, ticks=11872/0, in_queue=11872, util=59.89% sdg: ios=1119/0, merge=0/0, ticks=11256/0, in_queue=11256, util=70.29% sdh: ios=1128/0, merge=0/0, ticks=11764/0, in_queue=11764, util=59.18% sdi: ios=1095/0, merge=0/0, ticks=11552/0, in_queue=11552, util=73.42% sdj: ios=1062/0, merge=0/0, ticks=11372/0, in_queue=11372, util=57.24% sdk: ios=1087/0, merge=0/0, ticks=11344/0, in_queue=11344, util=71.08% sdaf: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdag: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdb: ios=1112/0, merge=0/0, ticks=11676/0, in_queue=11676, util=58.58% ---- test3: (g=0): rw=randread, bs=1M-1M/1M-1M, ioengine=sync, iodepth=1 fio 2.0.4 Starting 1 process test3: (groupid=0, jobs=1): err= 0: pid=19157 read : io=769024KB, bw=76849KB/s, iops=75 , runt= 10007msec clat (msec): min=9 , max=22 , avg=13.32, stdev= 1.60 lat (msec): min=9 , max=22 , avg=13.32, stdev= 1.60 clat percentiles (usec): | 1.00th=[10816], 5.00th=[11328], 10.00th=[11712], 20.00th=[12224], | 30.00th=[12608], 40.00th=[12864], 50.00th=[13120], 60.00th=[13376], | 70.00th=[13760], 80.00th=[14016], 90.00th=[14656], 95.00th=[15296], | 99.00th=[20608], 99.50th=[21120], 99.90th=[22400] bw (KB/s) : min=72000, max=79395, per=100.00%, avg=76960.79, stdev=1873.61 lat (msec) : 10=0.13%, 20=98.27%, 50=1.60% cpu : usr=0.00%, sys=3.48%, ctx=811, majf=0, minf=284 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 : total=r=751/w=0/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=769024KB, aggrb=76848KB/s, minb=78692KB/s, maxb=78692KB/s, mint=10007msec, maxt=10007msec Disk stats (read/write): dm-0: ios=190464/0, merge=0/0, ticks=1695940/0, in_queue=1695940, util=98.03%, aggrios=96128/0, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md0: ios=96128/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=502/0, aggrmerge=7508/0, aggrticks=4517/0, aggrin_queue=4517, aggrutil=55.56% sdc: ios=583/0, merge=8745/0, ticks=5100/0, in_queue=5100, util=50.53% sdd: ios=604/0, merge=8996/0, ticks=5408/0, in_queue=5408, util=53.34% sde: ios=607/0, merge=9073/0, ticks=5500/0, in_queue=5500, util=54.37% sdf: ios=595/0, merge=8893/0, ticks=5276/0, in_queue=5276, util=52.15% sdg: ios=609/0, merge=9087/0, ticks=5532/0, in_queue=5532, util=54.61% sdh: ios=621/0, merge=9299/0, ticks=5612/0, in_queue=5612, util=55.56% sdi: ios=619/0, merge=9205/0, ticks=5580/0, in_queue=5580, util=55.01% sdj: ios=594/0, merge=8878/0, ticks=5464/0, in_queue=5464, util=53.98% sdk: ios=597/0, merge=8939/0, ticks=5316/0, in_queue=5316, util=52.60% sdaf: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdag: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdb: ios=601/0, merge=8983/0, ticks=5420/0, in_queue=5420, util=53.55% md1: ios=96128/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=503/0, aggrmerge=7507/0, aggrticks=4469/0, aggrin_queue=4469, aggrutil=55.77% sdm: ios=589/0, merge=8739/0, ticks=5320/0, in_queue=5320, util=52.40% sdn: ios=601/0, merge=8999/0, ticks=5200/0, in_queue=5200, util=51.41% sdo: ios=610/0, merge=9070/0, ticks=5440/0, in_queue=5440, util=53.63% sdp: ios=593/0, merge=8895/0, ticks=5284/0, in_queue=5284, util=52.36% sdq: ios=610/0, merge=9086/0, ticks=5320/0, in_queue=5320, util=52.40% sdr: ios=623/0, merge=9297/0, ticks=5648/0, in_queue=5648, util=55.77% sds: ios=618/0, merge=9206/0, ticks=5592/0, in_queue=5592, util=55.21% sdt: ios=594/0, merge=8878/0, ticks=5204/0, in_queue=5204, util=51.45% sdu: ios=600/0, merge=8936/0, ticks=5324/0, in_queue=5324, util=52.52% sdah: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdai: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdl: ios=603/0, merge=8981/0, ticks=5296/0, in_queue=5296, util=52.16% ---- test4: (g=0): rw=randread, bs=1M-1M/1M-1M, ioengine=sync, iodepth=1 fio 2.0.4 Starting 1 process test4: (groupid=0, jobs=1): err= 0: pid=23762 read : io=462848KB, bw=46257KB/s, iops=45 , runt= 10006msec clat (msec): min=11 , max=267 , avg=22.13, stdev=19.49 lat (msec): min=11 , max=267 , avg=22.13, stdev=19.49 clat percentiles (msec): | 1.00th=[ 14], 5.00th=[ 16], 10.00th=[ 17], 20.00th=[ 19], | 30.00th=[ 20], 40.00th=[ 20], 50.00th=[ 21], 60.00th=[ 22], | 70.00th=[ 23], 80.00th=[ 23], 90.00th=[ 25], 95.00th=[ 25], | 99.00th=[ 34], 99.50th=[ 245], 99.90th=[ 269] bw (KB/s) : min= 3923, max=54748, per=100.00%, avg=46260.32, stdev=12218.61 lat (msec) : 20=42.92%, 50=56.19%, 100=0.22%, 250=0.22%, 500=0.44% cpu : usr=0.08%, sys=1.64%, ctx=470, majf=0, minf=284 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 : total=r=452/w=0/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=462848KB, aggrb=46257KB/s, minb=47367KB/s, maxb=47367KB/s, mint=10006msec, maxt=10006msec Disk stats (read/write): md6: ios=114432/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=57856/0, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md0: ios=57856/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=302/0, aggrmerge=4519/0, aggrticks=4782/0, aggrin_queue=4782, aggrutil=59.46% sdc: ios=360/0, merge=5368/0, ticks=5676/0, in_queue=5676, util=55.89% sdd: ios=365/0, merge=5427/0, ticks=5988/0, in_queue=5988, util=58.98% sde: ios=369/0, merge=5535/0, ticks=6000/0, in_queue=6000, util=59.46% sdf: ios=365/0, merge=5475/0, ticks=5628/0, in_queue=5628, util=55.77% sdg: ios=361/0, merge=5383/0, ticks=5548/0, in_queue=5548, util=54.74% sdh: ios=357/0, merge=5323/0, ticks=5592/0, in_queue=5592, util=55.18% sdi: ios=354/0, merge=5294/0, ticks=5736/0, in_queue=5736, util=56.69% sdj: ios=365/0, merge=5475/0, ticks=5872/0, in_queue=5872, util=58.20% sdk: ios=369/0, merge=5535/0, ticks=5736/0, in_queue=5736, util=56.85% sdaf: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdag: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdb: ios=362/0, merge=5414/0, ticks=5616/0, in_queue=5616, util=55.42% md1: ios=57856/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=301/0, aggrmerge=4519/0, aggrticks=4770/0, aggrin_queue=4770, aggrutil=59.15% sdm: ios=359/0, merge=5369/0, ticks=5708/0, in_queue=5708, util=56.45% sdn: ios=362/0, merge=5430/0, ticks=5668/0, in_queue=5668, util=56.17% sdo: ios=371/0, merge=5533/0, ticks=6000/0, in_queue=6000, util=59.15% sdp: ios=366/0, merge=5474/0, ticks=5900/0, in_queue=5900, util=58.35% sdq: ios=359/0, merge=5385/0, ticks=5804/0, in_queue=5804, util=57.52% sdr: ios=355/0, merge=5325/0, ticks=5492/0, in_queue=5492, util=54.43% sds: ios=353/0, merge=5295/0, ticks=5436/0, in_queue=5436, util=53.88% sdt: ios=365/0, merge=5475/0, ticks=5620/0, in_queue=5620, util=55.70% sdu: ios=370/0, merge=5534/0, ticks=5700/0, in_queue=5700, util=56.29% sdah: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdai: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdl: ios=362/0, merge=5414/0, ticks=5920/0, in_queue=5920, util=58.55% ---- test5: (g=0): rw=randread, bs=1M-1M/1M-1M, ioengine=sync, iodepth=1 fio 2.0.4 Starting 1 process test5: (groupid=0, jobs=1): err= 0: pid=32210 read : io=504832KB, bw=50453KB/s, iops=49 , runt= 10006msec clat (msec): min=11 , max=60 , avg=20.29, stdev= 3.76 lat (msec): min=11 , max=60 , avg=20.29, stdev= 3.76 clat percentiles (usec): | 1.00th=[13248], 5.00th=[15680], 10.00th=[16768], 20.00th=[18048], | 30.00th=[18816], 40.00th=[19584], 50.00th=[20096], 60.00th=[20864], | 70.00th=[21632], 80.00th=[22400], 90.00th=[23424], 95.00th=[24704], | 99.00th=[25984], 99.50th=[49920], 99.90th=[60160] bw (KB/s) : min=39922, max=54425, per=99.82%, avg=50360.74, stdev=3005.20 lat (msec) : 20=48.68%, 50=50.71%, 100=0.61% cpu : usr=0.00%, sys=0.76%, ctx=499, majf=0, minf=284 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 : total=r=493/w=0/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=504832KB, aggrb=50452KB/s, minb=51663KB/s, maxb=51663KB/s, mint=10006msec, maxt=10006msec Disk stats (read/write): md0: ios=7808/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=328/0, aggrmerge=0/0, aggrticks=4925/0, aggrin_queue=4925, aggrutil=61.63% sdb: ios=395/0, merge=0/0, ticks=5652/0, in_queue=5652, util=56.00% sdc: ios=404/0, merge=0/0, ticks=5932/0, in_queue=5932, util=58.78% sdd: ios=390/0, merge=0/0, ticks=5856/0, in_queue=5856, util=58.03% sde: ios=397/0, merge=0/0, ticks=6180/0, in_queue=6180, util=61.24% sdf: ios=396/0, merge=0/0, ticks=5940/0, in_queue=5940, util=58.86% sdg: ios=392/0, merge=0/0, ticks=5772/0, in_queue=5772, util=57.19% sdh: ios=385/0, merge=0/0, ticks=5600/0, in_queue=5600, util=55.49% sdi: ios=377/0, merge=0/0, ticks=5800/0, in_queue=5800, util=57.47% sdj: ios=378/0, merge=0/0, ticks=5768/0, in_queue=5768, util=57.15% sdk: ios=394/0, merge=0/0, ticks=5820/0, in_queue=5820, util=57.67% sdl: ios=398/0, merge=0/0, ticks=6108/0, in_queue=6108, util=60.52% sdm: ios=390/0, merge=0/0, ticks=5856/0, in_queue=5856, util=58.03% sdn: ios=402/0, merge=0/0, ticks=6000/0, in_queue=6000, util=59.45% sdo: ios=400/0, merge=0/0, ticks=6220/0, in_queue=6220, util=61.63% sdp: ios=398/0, merge=0/0, ticks=6068/0, in_queue=6068, util=60.13% sdq: ios=401/0, merge=0/0, ticks=6200/0, in_queue=6200, util=61.44% sdr: ios=401/0, merge=0/0, ticks=5832/0, in_queue=5832, util=57.79% sds: ios=392/0, merge=0/0, ticks=5820/0, in_queue=5820, util=57.68% sdt: ios=401/0, merge=0/0, ticks=5908/0, in_queue=5908, util=58.55% sdu: ios=397/0, merge=0/0, ticks=5888/0, in_queue=5888, util=58.35% sdaf: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdag: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdah: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdai: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% ---- test6: (g=0): rw=randread, bs=1M-1M/1M-1M, ioengine=sync, iodepth=1 fio 2.0.4 Starting 1 process test6: (groupid=0, jobs=1): err= 0: pid=1850 read : io=801792KB, bw=80163KB/s, iops=78 , runt= 10002msec clat (msec): min=9 , max=60 , avg=12.77, stdev= 2.77 lat (msec): min=9 , max=60 , avg=12.77, stdev= 2.77 clat percentiles (usec): | 1.00th=[10048], 5.00th=[10944], 10.00th=[11328], 20.00th=[11712], | 30.00th=[12096], 40.00th=[12352], 50.00th=[12608], 60.00th=[12864], | 70.00th=[13120], 80.00th=[13376], 90.00th=[13888], 95.00th=[14144], | 99.00th=[19840], 99.50th=[28032], 99.90th=[60672] bw (KB/s) : min=64631, max=84329, per=100.00%, avg=80169.58, stdev=4137.01 lat (msec) : 10=0.89%, 20=98.21%, 50=0.64%, 100=0.26% cpu : usr=0.04%, sys=1.36%, ctx=802, majf=0, minf=284 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 : total=r=783/w=0/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=801792KB, aggrb=80163KB/s, minb=82087KB/s, maxb=82087KB/s, mint=10002msec, maxt=10002msec Disk stats (read/write): dm-0: ios=12416/0, merge=0/0, ticks=108252/0, in_queue=108252, util=98.82%, aggrios=12528/0, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md0: ios=12528/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=522/0, aggrmerge=0/0, aggrticks=4547/0, aggrin_queue=4547, aggrutil=55.80% sdb: ios=637/0, merge=0/0, ticks=5492/0, in_queue=5492, util=54.41% sdc: ios=634/0, merge=0/0, ticks=5320/0, in_queue=5320, util=52.71% sdd: ios=631/0, merge=0/0, ticks=5588/0, in_queue=5588, util=55.37% sde: ios=629/0, merge=0/0, ticks=5584/0, in_queue=5584, util=55.33% sdf: ios=620/0, merge=0/0, ticks=5552/0, in_queue=5552, util=55.01% sdg: ios=610/0, merge=0/0, ticks=5420/0, in_queue=5420, util=53.70% sdh: ios=631/0, merge=0/0, ticks=5468/0, in_queue=5468, util=54.18% sdi: ios=619/0, merge=0/0, ticks=5416/0, in_queue=5416, util=53.66% sdj: ios=630/0, merge=0/0, ticks=5424/0, in_queue=5424, util=53.74% sdk: ios=630/0, merge=0/0, ticks=5564/0, in_queue=5564, util=55.13% sdl: ios=607/0, merge=0/0, ticks=5200/0, in_queue=5200, util=51.52% sdm: ios=637/0, merge=0/0, ticks=5544/0, in_queue=5544, util=54.93% sdn: ios=619/0, merge=0/0, ticks=5416/0, in_queue=5416, util=53.66% sdo: ios=640/0, merge=0/0, ticks=5568/0, in_queue=5568, util=55.17% sdp: ios=636/0, merge=0/0, ticks=5632/0, in_queue=5632, util=55.80% sdq: ios=615/0, merge=0/0, ticks=5376/0, in_queue=5376, util=53.26% sdr: ios=622/0, merge=0/0, ticks=5284/0, in_queue=5284, util=52.35% sds: ios=618/0, merge=0/0, ticks=5428/0, in_queue=5428, util=53.78% sdt: ios=631/0, merge=0/0, ticks=5528/0, in_queue=5528, util=54.78% sdu: ios=632/0, merge=0/0, ticks=5340/0, in_queue=5340, util=52.91% sdaf: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdag: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdah: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% sdai: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00% ---- test7: (g=0): rw=randread, bs=1M-1M/1M-1M, ioengine=sync, iodepth=1 fio 2.0.4 Starting 1 process test7: (groupid=0, jobs=1): err= 0: pid=13783 read : io=505856KB, bw=50545KB/s, iops=49 , runt= 10008msec clat (msec): min=11 , max=31 , avg=20.25, stdev= 2.89 lat (msec): min=11 , max=31 , avg=20.25, stdev= 2.89 clat percentiles (usec): | 1.00th=[13760], 5.00th=[15552], 10.00th=[16768], 20.00th=[17792], | 30.00th=[18560], 40.00th=[19328], 50.00th=[20096], 60.00th=[20864], | 70.00th=[21888], 80.00th=[22912], 90.00th=[23936], 95.00th=[24960], | 99.00th=[26240], 99.50th=[27776], 99.90th=[31616] bw (KB/s) : min=48282, max=52965, per=99.93%, avg=50507.63, stdev=1511.43 lat (msec) : 20=47.37%, 50=52.63% cpu : usr=0.00%, sys=0.72%, ctx=501, majf=0, minf=284 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 : total=r=494/w=0/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=505856KB, aggrb=50545KB/s, minb=51758KB/s, maxb=51758KB/s, mint=10008msec, maxt=10008msec Disk stats (read/write): md0: ios=7824/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=395/0, aggrmerge=0/0, aggrticks=5965/0, aggrin_queue=5965, aggrutil=61.25% sdb: ios=396/0, merge=0/0, ticks=5732/0, in_queue=5732, util=56.77% sdba: ios=405/0, merge=0/0, ticks=6124/0, in_queue=6124, util=60.65% sdbb: ios=391/0, merge=0/0, ticks=6016/0, in_queue=6016, util=59.58% sdbc: ios=398/0, merge=0/0, ticks=6184/0, in_queue=6184, util=61.25% sdbd: ios=397/0, merge=0/0, ticks=5928/0, in_queue=5928, util=58.72% sdbg: ios=393/0, merge=0/0, ticks=6084/0, in_queue=6084, util=60.26% sdbh: ios=386/0, merge=0/0, ticks=5884/0, in_queue=5884, util=58.28% sdbi: ios=378/0, merge=0/0, ticks=5856/0, in_queue=5856, util=58.00% sdbl: ios=379/0, merge=0/0, ticks=5948/0, in_queue=5948, util=58.91% sdbr: ios=394/0, merge=0/0, ticks=5988/0, in_queue=5988, util=59.31% sdbs: ios=398/0, merge=0/0, ticks=6072/0, in_queue=6072, util=60.14% sdc: ios=390/0, merge=0/0, ticks=5712/0, in_queue=5712, util=56.58% sdd: ios=402/0, merge=0/0, ticks=5912/0, in_queue=5912, util=58.56% sde: ios=401/0, merge=0/0, ticks=6140/0, in_queue=6140, util=60.82% sdf: ios=399/0, merge=0/0, ticks=5844/0, in_queue=5844, util=57.88% sdg: ios=402/0, merge=0/0, ticks=6032/0, in_queue=6032, util=59.75% sdh: ios=402/0, merge=0/0, ticks=5976/0, in_queue=5976, util=59.19% sdi: ios=393/0, merge=0/0, ticks=5952/0, in_queue=5952, util=58.95% sdj: ios=402/0, merge=0/0, ticks=6088/0, in_queue=6088, util=60.30% sdk: ios=398/0, merge=0/0, ticks=5828/0, in_queue=5828, util=57.73% ---- test8: (g=0): rw=randread, bs=1M-1M/1M-1M, ioengine=sync, iodepth=1 fio 2.0.4 Starting 1 process test8: (groupid=0, jobs=1): err= 0: pid=14153 read : io=707584KB, bw=70751KB/s, iops=69 , runt= 10001msec clat (msec): min=8 , max=607 , avg=14.47, stdev=31.84 lat (msec): min=8 , max=607 , avg=14.47, stdev=31.84 clat percentiles (msec): | 1.00th=[ 11], 5.00th=[ 12], 10.00th=[ 12], 20.00th=[ 12], | 30.00th=[ 13], 40.00th=[ 13], 50.00th=[ 13], 60.00th=[ 13], | 70.00th=[ 14], 80.00th=[ 14], 90.00th=[ 15], 95.00th=[ 15], | 99.00th=[ 20], 99.50th=[ 22], 99.90th=[ 611] bw (KB/s) : min= 1686, max=82483, per=100.00%, avg=71972.26, stdev=24807.51 lat (msec) : 10=0.29%, 20=98.84%, 50=0.58%, 750=0.29% cpu : usr=0.04%, sys=1.20%, ctx=711, majf=0, minf=284 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 : total=r=691/w=0/d=0, short=r=0/w=0/d=0 Run status group 0 (all jobs): READ: io=707584KB, aggrb=70751KB/s, minb=72449KB/s, maxb=72449KB/s, mint=10001msec, maxt=10001msec Disk stats (read/write): dm-0: ios=10944/0, merge=0/0, ticks=101672/0, in_queue=101712, util=98.78%, aggrios=11056/0, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00% md0: ios=11056/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=552/0, aggrmerge=0/0, aggrticks=5137/0, aggrin_queue=5137, aggrutil=54.71% sdb: ios=565/0, merge=0/0, ticks=4988/0, in_queue=4988, util=49.41% sdba: ios=560/0, merge=0/0, ticks=5004/0, in_queue=5004, util=49.56% sdbb: ios=554/0, merge=0/0, ticks=5488/0, in_queue=5488, util=54.36% sdbc: ios=552/0, merge=0/0, ticks=5524/0, in_queue=5524, util=54.71% sdbd: ios=545/0, merge=0/0, ticks=4744/0, in_queue=4744, util=46.99% sdbg: ios=535/0, merge=0/0, ticks=5376/0, in_queue=5376, util=53.25% sdbh: ios=558/0, merge=0/0, ticks=4960/0, in_queue=4960, util=49.13% sdbi: ios=542/0, merge=0/0, ticks=4764/0, in_queue=4764, util=47.19% sdbl: ios=556/0, merge=0/0, ticks=5480/0, in_queue=5480, util=54.28% sdbr: ios=555/0, merge=0/0, ticks=5452/0, in_queue=5452, util=54.01% sdbs: ios=540/0, merge=0/0, ticks=5408/0, in_queue=5408, util=53.57% sdc: ios=569/0, merge=0/0, ticks=5340/0, in_queue=5340, util=52.90% sdd: ios=549/0, merge=0/0, ticks=4888/0, in_queue=4888, util=48.42% sde: ios=568/0, merge=0/0, ticks=5016/0, in_queue=5016, util=49.69% sdf: ios=560/0, merge=0/0, ticks=5032/0, in_queue=5032, util=49.85% sdg: ios=544/0, merge=0/0, ticks=4744/0, in_queue=4744, util=46.99% sdh: ios=547/0, merge=0/0, ticks=4860/0, in_queue=4860, util=48.14% sdi: ios=546/0, merge=0/0, ticks=5320/0, in_queue=5320, util=52.70% sdj: ios=554/0, merge=0/0, ticks=5452/0, in_queue=5452, util=54.01% sdk: ios=557/0, merge=0/0, ticks=4912/0, in_queue=4912, util=48.66%