There is a strange thing on my server which has a mysql running on it. The QPS is more than 4000 but TPS is less than 20. The server load is more than 80 and cpu usr is more than 86% but iowait is less than 8%. The disk iops is more than 16000 and util of disk is more than 99%. When the QPS decreases, the load decreases, the cpu iowait increases. I can't catch this! root@mypc # dmidecode | grep "Product Name" Product Name: PowerEdge R510 Product Name: 084YMW root@mypc # megacli -PDList -aALL |grep "Inquiry Data" Inquiry Data: SEAGATE ST3600057SS ES656SL316PT Inquiry Data: SEAGATE ST3600057SS ES656SL30THV Inquiry Data: ATA INTEL SSDSA2CW300362CVPR201602A6300EGN Inquiry Data: ATA INTEL SSDSA2CW300362CVPR2044037K300EGN Inquiry Data: ATA INTEL SSDSA2CW300362CVPR204402PX300EGN Inquiry Data: ATA INTEL SSDSA2CW300362CVPR204403WN300EGN Inquiry Data: ATA INTEL SSDSA2CW300362CVPR202000HU300EGN Inquiry Data: ATA INTEL SSDSA2CW300362CVPR202001E7300EGN Inquiry Data: ATA INTEL SSDSA2CW300362CVPR204402WE300EGN Inquiry Data: ATA INTEL SSDSA2CW300362CVPR204404E5300EGN Inquiry Data: ATA INTEL SSDSA2CW300362CVPR204401QF300EGN Inquiry Data: ATA INTEL SSDSA2CW300362CVPR20450001300EGN the mysql data files lie on the ssd disks which are organizaed using RAID 10. root@mypc # megacli -LDInfo -L1 -a0 Adapter 0 -- Virtual Drive Information: Virtual Disk: 1 (Target Id: 1) Name: RAID Level: Primary-1, Secondary-0, RAID Level Qualifier-0 Size:1427840MB State: Optimal Stripe Size: 64kB Number Of Drives:2 Span Depth:5 Default Cache Policy: WriteThrough, ReadAheadNone, Direct, No Write Cache if Bad BBU Current Cache Policy: WriteThrough, ReadAheadNone, Direct, No Write Cache if Bad BBU Access Policy: Read/Write Disk Cache Policy: Disk's Default Exit Code: 0x00 -------- -----load-avg---- ---cpu-usage--- ---swap--- -------------------------io-usage----------------------- -QPS- -TPS- -Hit%- time | 1m 5m 15m |usr sys idl iow| si so| r/s w/s rkB/s wkB/s queue await svctm %util| ins upd del sel iud| lor hit| 09:05:29|79.80 64.49 42.00| 82 7 6 5| 0 0|16421.1 10.6262705.9 85.2 8.3 0.5 0.1 99.5| 0 0 0 3968 0| 495482 96.58| 09:05:30|79.80 64.49 42.00| 79 7 8 6| 0 0|15907.4 230.6254409.7 6357.5 8.4 0.5 0.1 98.5| 0 0 0 4195 0| 496434 96.68| 09:05:31|81.34 65.07 42.31| 81 7 7 5| 0 0|16198.7 8.6259029.2 99.8 8.1 0.5 0.1 99.3| 0 0 0 4220 0| 508983 96.70| 09:05:32|81.34 65.07 42.31| 82 7 5 5| 0 0|16746.6 8.7267853.3 92.4 8.5 0.5 0.1 99.4| 0 0 0 4084 0| 503834 96.54| 09:05:33|81.34 65.07 42.31| 81 7 6 5| 0 0|16498.7 9.6263856.8 92.3 8.0 0.5 0.1 99.3| 0 0 0 4030 0| 507051 96.60| 09:05:34|81.34 65.07 42.31| 80 8 7 6| 0 0|16328.4 11.5261101.6 95.8 8.1 0.5 0.1 98.3| 0 0 0 4119 0| 504409 96.63| 09:05:35|81.31 65.33 42.52| 82 7 6 5| 0 0|16374.0 8.7261921.9 92.5 8.1 0.5 0.1 99.7| 0 0 0 4127 0| 507279 96.66| 09:05:36|81.31 65.33 42.52| 81 8 6 5| 0 0|16496.2 8.6263832.0 84.5 8.5 0.5 0.1 99.2| 0 0 0 4100 0| 505054 96.59| 09:05:37|81.31 65.33 42.52| 82 8 6 4| 0 0|16239.4 9.6259768.8 84.3 8.0 0.5 0.1 99.1| 0 0 0 4273 0| 510621 96.72| 09:05:38|81.31 65.33 42.52| 81 7 6 5| 0 0|16349.6 8.7261439.2 81.4 8.2 0.5 0.1 98.9| 0 0 0 4171 0| 510145 96.67| 09:05:39|81.31 65.33 42.52| 82 7 6 5| 0 0|16116.8 8.7257667.6 96.5 8.0 0.5 0.1 99.1| 0 0 0 4348 0| 513093 96.74| 09:05:40|79.60 65.24 42.61| 79 7 7 7| 0 0|16154.2 242.9258390.4 6388.4 8.5 0.5 0.1 99.0| 0 0 0 4033 0| 507244 96.70| 09:05:41|79.60 65.24 42.61| 79 7 8 6| 0 0|16583.1 21.2265129.6 173.5 8.2 0.5 0.1 99.1| 0 0 0 3995 0| 501474 96.57| 09:05:42|79.60 65.24 42.61| 81 8 6 5| 0 0|16281.0 9.7260372.2 69.5 8.3 0.5 0.1 98.7| 0 0 0 4221 0| 509322 96.70| 09:05:43|79.60 65.24 42.61| 80 7 7 6| 0 0|16355.3 8.7261515.5 104.3 8.2 0.5 0.1 99.6| 0 0 0 4087 0| 502052 96.62| -------- -----load-avg---- ---cpu-usage--- ---swap--- -------------------------io-usage----------------------- -QPS- -TPS- -Hit%- time | 1m 5m 15m |usr sys idl iow| si so| r/s w/s rkB/s wkB/s queue await svctm %util| ins upd del sel iud| lor hit| 09:05:44|79.60 65.24 42.61| 83 7 5 4| 0 0|16469.4 11.6263387.0 138.8 8.2 0.5 0.1 98.7| 0 0 0 4292 0| 509979 96.65| 09:05:45|79.07 65.37 42.77| 80 7 6 6| 0 0|16659.5 9.7266478.7 85.0 8.4 0.5 0.1 98.5| 0 0 0 3899 0| 496234 96.54| 09:05:46|79.07 65.37 42.77| 78 7 7 8| 0 0|16752.9 8.7267921.8 97.1 8.4 0.5 0.1 98.9| 0 0 0 4126 0| 508300 96.57| 09:05:47|79.07 65.37 42.77| 82 7 6 5| 0 0|16657.2 9.6266439.3 84.3 8.3 0.5 0.1 98.9| 0 0 0 4086 0| 502171 96.57| 09:05:48|79.07 65.37 42.77| 79 8 6 6| 0 0|16814.5 8.7268924.1 77.6 8.5 0.5 0.1 99.0| 0 0 0 4059 0| 499645 96.52| 09:05:49|79.07 65.37 42.77| 81 7 6 5| 0 0|16553.0 6.8264708.6 42.5 8.3 0.5 0.1 99.4| 0 0 0 4249 0| 501623 96.60| 09:05:50|79.63 65.71 43.01| 79 7 7 7| 0 0|16295.1 246.9260475.0 6442.4 8.7 0.5 0.1 99.1| 0 0 0 4231 0| 511032 96.70| 09:05:51|79.63 65.71 43.01| 80 7 6 6| 0 0|16568.9 8.7264919.7 104.7 8.3 0.5 0.1 99.7| 0 0 0 4272 0| 517177 96.68| 09:05:53|79.63 65.71 43.01| 79 7 7 6| 0 0|16539.0 8.6264502.9 87.6 8.4 0.5 0.1 98.9| 0 0 0 3992 0| 496728 96.52| 09:05:54|79.63 65.71 43.01| 79 7 7 7| 0 0|16527.5 11.6264363.6 92.6 8.5 0.5 0.1 98.8| 0 0 0 4045 0| 502944 96.59| 09:05:55|79.63 65.71 43.01| 80 7 7 6| 0 0|16374.7 12.5261687.2 134.9 8.6 0.5 0.1 99.2| 0 0 0 4143 0| 507006 96.66| 09:05:56|76.05 65.20 42.96| 77 8 8 8| 0 0|16464.9 9.6263314.3 111.9 8.5 0.5 0.1 98.9| 0 0 0 4250 0| 505417 96.64| 09:05:57|76.05 65.20 42.96| 79 7 6 7| 0 0|16460.1 8.8263283.2 93.4 8.3 0.5 0.1 98.8| 0 0 0 4294 0| 508168 96.66| 09:05:58|76.05 65.20 42.96| 80 7 7 7| 0 0|16176.5 9.6258762.1 127.3 8.3 0.5 0.1 98.9| 0 0 0 4160 0| 509349 96.72| 09:05:59|76.05 65.20 42.96| 75 7 9 10| 0 0|16522.0 10.7264274.6 93.1 8.6 0.5 0.1 97.5| 0 0 0 4034 0| 492623 96.51| -------- -----load-avg---- ---cpu-usage--- ---swap--- -------------------------io-usage----------------------- -QPS- -TPS- -Hit%- time | 1m 5m 15m |usr sys idl iow| si so| r/s w/s rkB/s wkB/s queue await svctm %util| ins upd del sel iud| lor hit| 09:06:00|76.05 65.20 42.96| 79 7 7 7| 0 0|16369.6 21.2261867.3 262.5 8.4 0.5 0.1 98.9| 0 0 0 4305 0| 494509 96.59| 09:06:01|75.33 65.23 43.09| 73 6 9 12| 0 0|15864.0 209.3253685.4 6238.0 10.0 0.6 0.1 98.7| 0 0 0 3913 0| 483480 96.62| 09:06:02|75.33 65.23 43.09| 73 7 8 12| 0 0|15854.7 12.7253613.2 93.6 11.0 0.7 0.1 99.0| 0 0 0 4271 0| 483771 96.64| 09:06:03|75.33 65.23 43.09| 75 7 9 9| 0 0|16074.8 8.7257104.3 81.7 8.1 0.5 0.1 98.5| 0 0 0 4060 0| 480701 96.55| 09:06:04|75.33 65.23 43.09| 76 7 8 9| 0 0|16221.7 9.7259500.1 139.4 8.1 0.5 0.1 97.6| 0 0 0 3953 0| 486774 96.56| 09:06:05|74.98 65.33 43.24| 78 7 8 8| 0 0|16330.7 8.7261166.5 85.3 8.2 0.5 0.1 98.5| 0 0 0 3957 0| 481775 96.53| 09:06:06|74.98 65.33 43.24| 75 7 9 9| 0 0|16093.7 11.7257436.1 93.7 8.2 0.5 0.1 99.2| 0 0 0 3938 0| 489251 96.60| 09:06:07|74.98 65.33 43.24| 75 7 5 13| 0 0|15758.9 19.2251989.4 188.2 14.7 0.9 0.1 99.7| 0 0 0 4140 0| 494738 96.70| 09:06:08|74.98 65.33 43.24| 69 7 10 15| 0 0|16166.3 8.7258474.9 81.2 8.9 0.5 0.1 98.7| 0 0 0 3993 0| 487162 96.58| 09:06:09|74.98 65.33 43.24| 74 7 9 10| 0 0|16071.0 8.7257010.9 93.3 8.2 0.5 0.1 99.2| 0 0 0 4098 0| 491557 96.61| 09:06:10|70.98 64.66 43.14| 71 7 9 12| 0 0|15549.6 216.1248701.1 6188.7 8.3 0.5 0.1 97.8| 0 0 0 3879 0| 480832 96.66| 09:06:11|70.98 64.66 43.14| 71 7 10 13| 0 0|16233.7 22.4259568.1 257.1 8.2 0.5 0.1 99.2| 0 0 0 4088 0| 493200 96.62| 09:06:12|70.98 64.66 43.14| 78 7 8 7| 0 0|15932.4 10.6254779.5 108.1 8.1 0.5 0.1 98.6| 0 0 0 4168 0| 489838 96.63| 09:06:13|70.98 64.66 43.14| 71 8 9 12| 0 0|16255.9 11.5259902.3 103.9 8.3 0.5 0.1 98.0| 0 0 0 3874 0| 481246 96.52| 09:06:14|70.98 64.66 43.14| 60 6 16 18| 0 0|15621.0 9.7249826.1 81.9 8.0 0.5 0.1 99.3| 0 0 0 3956 0| 480278 96.65|