Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
iostat -k -x monitoring This test has the advantage of being measurable on a heavily-loaded production resource. I was able to get good data from times when our production server (2 15kRPM disk RAID1) was under 100% disk utilization load. On new Sun Fire x4240 servers with DRBD, I created sustained load with pgbench -c 32 -t 50000. An odd thing is that pgbench returns better benchmarks on the current production server, if our historical records are accurate, anyways. But when watching how much is actually being sent to the disk, the newer configuration with DRBD seems about ten times better than current production hardware, and I think this is a more reliable test. This is also consistent with other tests which show a performance improvement of about 2x when the DRBD secondary is disconnected. * CURRENT PRODUCTION: Average kB/s write speed: 1686.92 Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0.20 123.22 350.10 55.60 5593.48 1534.83 2796.74 767.41 17.57 4.98 12.35 2.49 100.94 sda 4.67 30.02 440.57 22.92 9989.45 524.14 4994.73 262.07 22.68 2.31 4.98 2.06 95.66 sda 0.00 43.70 363.62 28.86 5913.82 734.96 2956.91 367.48 16.94 3.76 9.59 2.48 97.32 sda 0.00 45.25 324.24 26.87 5207.27 698.18 2603.64 349.09 16.82 2.62 7.46 2.75 96.57 sda 0.00 53.81 361.03 36.91 5972.78 852.78 2986.39 426.39 17.15 3.21 8.03 2.56 101.86 sda 0.20 42.54 342.94 30.06 5603.27 705.11 2801.64 352.56 16.91 4.42 11.83 2.74 102.33 sda 1.22 35.85 355.19 50.51 6030.14 975.97 3015.07 487.98 17.27 3.88 9.56 2.51 101.83 sda 0.00 66.13 356.80 50.30 6206.90 1049.90 3103.45 524.95 17.83 5.55 13.63 2.49 101.50 sda 0.20 41.37 345.78 26.51 5518.07 650.60 2759.04 325.30 16.57 5.43 14.57 2.68 99.68 sda 0.81 1329.70 283.03 78.59 4543.03 11338.99 2271.52 5669.49 43.92 15.82 43.72 2.76 99.88 sda 0.00 35.28 305.85 17.74 4962.90 566.13 2481.45 283.06 17.09 3.29 10.15 3.11 100.48 sda 0.00 43.93 321.05 25.30 5148.18 584.62 2574.09 292.31 16.55 4.88 14.16 2.92 101.30 sda 0.00 28.34 335.11 20.33 5409.45 504.31 2704.72 252.16 16.64 4.44 12.51 2.89 102.75 sda 0.21 150.31 327.01 57.53 5283.30 1916.70 2641.65 958.35 18.72 4.36 11.34 2.67 102.60 sda 0.21 1298.54 292.69 76.62 4733.19 11213.36 2366.60 5606.68 43.18 8.22 22.16 2.81 103.88 sda 1.02 381.97 255.12 67.83 4260.66 3962.30 2130.33 1981.15 25.46 8.75 27.14 3.16 102.13 sda 0.83 73.65 274.90 46.89 4426.56 1201.66 2213.28 600.83 17.49 5.96 18.47 3.16 101.66 sda 1.65 50.62 369.63 32.64 7033.06 928.93 3516.53 464.46 19.79 5.12 12.74 2.48 99.83 sda 53.78 44.38 895.50 57.26 26368.92 1092.84 13184.46 546.42 28.82 8.63 9.06 1.06 100.86 sda 73.77 1303.28 1156.97 85.45 33654.10 11359.02 16827.05 5679.51 36.23 18.45 14.82 0.82 101.89 sda 39.96 53.89 742.83 58.40 19800.00 1065.57 9900.00 532.79 26.04 7.81 9.70 1.27 101.97 sda 0.20 2305.47 417.41 176.52 7336.03 20089.07 3668.02 10044.53 46.18 22.34 37.73 1.71 101.30 sda 292.09 145.64 436.71 124.34 89179.72 2560.65 44589.86 1280.32 163.51 11.29 19.83 1.80 101.18 sda 138.54 445.64 460.65 217.65 83165.92 5879.11 41582.96 2939.55 131.28 12.61 18.58 1.50 101.42 sda 135.63 90.28 556.68 68.02 97361.94 1387.85 48680.97 693.93 158.08 23.54 37.41 1.62 101.38 sda 126.52 44.33 541.09 19.03 92034.01 568.42 46017.00 284.21 165.33 12.67 22.60 1.81 101.21 sda 94.53 1055.67 427.13 38.06 65488.26 2636.44 32744.13 1318.22 146.45 49.56 69.77 2.18 101.30 sda 92.48 228.86 321.95 57.11 48443.90 8609.76 24221.95 4304.88 150.51 30.10 124.90 2.68 101.71 sda 134.62 111.34 395.34 49.60 69872.06 1472.06 34936.03 736.03 160.35 16.49 37.11 2.28 101.30 sda 161.05 25.35 443.41 20.89 90185.80 520.89 45092.90 260.45 195.36 7.29 15.68 2.19 101.50 sda 107.51 140.16 446.04 53.75 92692.90 1585.40 46346.45 792.70 188.63 11.38 22.70 2.03 101.50 sda 122.52 32.86 560.45 19.27 106283.16 464.10 53141.58 232.05 184.14 6.88 11.93 1.75 101.50 sda 64.50 1301.42 460.85 68.97 46052.74 10959.84 23026.37 5479.92 107.61 9.70 15.73 1.91 101.42 sda 7.52 141.87 380.89 96.54 8173.98 2308.94 4086.99 1154.47 21.96 4.97 13.28 2.01 95.77 sda 7.47 120.00 292.53 95.56 6280.40 1963.64 3140.20 981.82 21.24 10.16 26.20 2.60 100.93 sda 17.89 670.73 317.68 40.45 14978.86 886.18 7489.43 443.09 44.30 7.23 16.02 2.59 92.60 sda 4.05 1856.68 234.21 122.47 4058.30 20965.18 2029.15 10482.59 70.16 14.69 45.35 2.81 100.40 sda 0.20 45.16 305.24 44.56 4874.19 829.03 2437.10 414.52 16.30 2.88 8.26 2.84 99.44 sda 0.00 1.62 282.15 6.69 4478.70 149.29 2239.35 74.65 16.02 2.46 8.52 3.49 100.77 sda 0.81 63.31 316.13 45.16 5193.55 996.77 2596.77 498.39 17.13 7.83 21.72 2.79 100.89 sda 0.00 1270.85 282.19 70.85 4618.62 10863.16 2309.31 5431.58 43.85 17.12 48.46 2.86 101.05 sda 0.20 34.28 337.32 26.57 5645.44 563.08 2822.72 281.54 17.06 4.91 13.52 2.78 101.34 sda 0.20 65.99 319.23 54.45 5078.54 1204.86 2539.27 602.43 16.81 9.63 25.75 2.71 101.13 sda 0.00 1258.27 317.74 71.17 5151.61 10741.94 2575.81 5370.97 40.87 12.69 32.63 2.59 100.89 sda 0.40 43.72 341.30 21.46 5519.03 602.43 2759.51 301.21 16.88 5.04 13.75 2.79 101.30 sda 0.61 72.47 326.72 33.20 5510.93 963.56 2755.47 481.78 17.99 10.83 30.06 2.81 101.30 sda 2.03 30.28 392.48 13.41 6980.49 408.13 3490.24 204.07 18.20 4.30 10.74 2.49 100.98 sda 6.46 38.79 388.28 26.06 8305.45 620.61 4152.73 310.30 21.54 4.58 11.09 2.43 100.69 sda 0.00 127.59 362.07 62.27 6325.35 1887.22 3162.68 943.61 19.35 5.91 13.81 2.39 101.50 sda 0.20 32.80 381.49 18.11 6675.25 571.43 3337.63 285.71 18.13 3.09 7.77 2.50 99.80 sda 0.00 155.56 350.91 50.10 5747.07 1819.80 2873.54 909.90 18.87 7.74 19.35 2.49 99.88 sda 0.20 48.79 370.24 28.95 6116.60 822.67 3058.30 411.34 17.38 5.09 12.67 2.54 101.30 sda 0.00 32.39 345.75 25.10 5515.79 728.74 2757.89 364.37 16.84 4.46 12.07 2.71 100.57 sda 0.40 71.72 344.24 55.56 5536.97 1239.60 2768.48 619.80 16.95 5.73 14.33 2.51 100.20 sda 0.00 40.28 362.75 35.83 5844.53 719.03 2922.27 359.51 16.47 5.11 12.85 2.54 101.21 sda 4.66 1254.25 368.62 70.65 8662.35 10735.22 4331.17 5367.61 44.16 11.48 26.13 2.27 99.84 sda 0.20 51.42 329.15 43.32 5246.96 983.00 2623.48 491.50 16.73 6.31 16.94 2.70 100.73 sda 0.20 1277.96 333.67 86.17 5548.70 11031.66 2774.35 5515.83 39.49 9.80 23.29 2.38 99.80 sda 0.40 1266.93 363.33 70.54 6010.42 10866.53 3005.21 5433.27 38.90 9.84 22.69 2.30 99.96 sda 0.00 63.11 339.14 48.57 5544.26 1059.02 2772.13 529.51 17.03 7.46 19.16 2.64 102.46 sda 0.40 90.51 352.93 38.99 6073.54 1118.38 3036.77 559.19 18.35 4.59 11.81 2.55 99.80 sda 1.42 106.10 331.71 48.58 5302.44 1334.96 2651.22 667.48 17.45 3.87 10.17 2.64 100.57 * NEW SUN FIRE x4240 CLUSTER (DRBD running with protocol C): Average kB/s write speed: 18280.49 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq- sz avgqu-sz await svctm %util drbd0 0.00 0.00 0.00 1381.17 0.00 21610.24 31.29 228.21 223.86 0.55 75.69 drbd0 0.00 0.00 0.00 801.28 0.00 14240.59 35.54 71.23 50.26 1.06 85.19 drbd0 0.00 0.00 0.00 927.80 0.00 11899.25 25.65 123.10 166.90 0.97 89.55 drbd0 0.00 0.00 0.00 393.57 0.00 9052.21 46.00 4.91 12.53 2.23 87.68 drbd0 0.00 0.00 0.00 392.19 0.00 8993.31 45.86 4.73 12.11 2.22 87.17 drbd0 0.00 0.00 0.00 2549.33 0.00 27588.53 21.64 427.99 134.36 0.37 93.88 drbd0 0.00 0.00 0.00 2625.44 0.00 18898.62 14.40 978.93 406.77 0.38 98.62 drbd0 0.00 0.00 0.00 1686.80 0.00 22007.23 26.09 219.14 130.11 0.45 75.95 drbd0 0.00 0.00 0.18 1066.84 0.71 21749.02 40.77 2.66 2.51 0.67 71.12 drbd0 0.00 0.00 0.00 3090.12 0.00 38816.28 25.12 233.81 62.17 0.25 78.49 drbd0 0.00 0.00 0.00 2596.43 0.00 18497.74 14.25 898.75 356.70 0.36 93.98 drbd0 0.00 0.00 0.00 1484.43 0.00 16417.56 22.12 391.39 273.83 0.64 95.21 drbd0 0.00 0.00 0.00 413.59 0.00 10113.04 48.90 5.70 13.79 2.08 86.05 drbd0 0.00 0.00 0.00 518.07 0.00 10294.81 39.74 11.67 22.57 1.63 84.44 drbd0 0.00 0.00 0.00 562.08 0.00 12738.87 45.33 4.48 7.98 1.56 87.55 drbd0 0.00 0.00 0.00 477.88 0.00 9833.46 41.15 10.47 21.91 1.84 87.92 drbd0 0.00 0.00 0.00 3826.10 0.00 38017.67 19.87 744.32 190.20 0.25 95.18 * NEW SUN FIRE x4240 CLUSTER (with DRBD secondary disconnected): Average kB/s write speed: 38543.34 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq- sz avgqu-sz await svctm %util drbd0 0.00 0.00 0.00 4856.09 0.00 47280.46 19.47 16.84 3.65 0.15 71.18 drbd0 0.00 0.00 0.00 3207.39 0.00 32246.69 20.11 4.52 1.72 0.13 42.22 drbd0 0.00 0.00 0.00 2675.51 0.00 39217.94 29.32 0.50 0.19 0.10 26.17 drbd0 0.00 0.00 0.20 5036.02 0.79 52669.29 20.92 52.49 10.57 0.14 69.69 drbd0 0.00 0.00 0.00 3403.19 0.00 33696.41 19.80 4.99 1.70 0.21 70.52 drbd0 0.00 0.00 0.00 2015.66 0.00 28346.77 28.13 0.42 0.21 0.09 18.40 drbd0 0.00 0.00 0.00 4527.74 0.00 53557.74 23.66 7.52 1.74 0.07 30.75 drbd0 0.00 0.00 0.00 3388.49 0.00 26375.85 15.57 9.69 3.19 0.24 81.70 drbd0 0.00 0.00 0.00 2289.02 0.00 28259.73 24.69 3.56 1.66 0.18 42.00 drbd0 0.00 0.00 0.00 2662.98 0.00 37339.53 28.04 0.61 0.24 0.09 23.84 drbd0 0.00 0.00 0.00 4568.43 0.00 47341.96 20.73 34.62 7.77 0.16 70.98 drbd0 0.00 0.00 0.00 3160.08 0.00 28546.77 18.07 8.46 3.03 0.19 58.75 drbd0 0.00 0.00 0.20 2766.60 0.79 42462.08 30.69 0.39 0.14 0.09 24.17 drbd0 0.00 0.00 0.00 4017.09 0.00 47566.60 23.68 14.12 3.39 0.13 52.23 drbd0 0.00 0.00 0.00 3600.19 0.00 29346.80 16.30 9.25 3.17 0.23 83.88 drbd0 0.00 0.00 0.00 2738.56 0.00 32945.94 24.06 2.92 1.20 0.18 50.09 drbd0 0.00 0.00 0.00 2489.88 0.00 33831.13 27.17 0.48 0.19 0.08 21.01 drbd0 0.00 0.00 0.00 5128.38 0.00 51743.63 20.18 23.32 4.72 0.17 84.75 drbd0 0.00 0.00 0.00 3077.88 0.00 30346.31 19.72 6.41 2.33 0.23 71.64 drbd0 0.00 0.00 0.00 2597.11 0.00 38963.39 30.01 0.47 0.19 0.11 28.13 drbd0 0.00 0.00 0.00 5163.50 0.00 56120.68 21.74 21.68 4.32 0.14 72.36 drbd0 0.00 0.00 0.00 3379.74 0.00 27410.41 16.22 11.97 3.92 0.23 78.81 drbd0 0.00 0.00 0.00 2516.51 0.00 35833.78 28.48 0.97 0.39 0.11 27.32 drbd0 0.00 0.00 0.39 4557.76 1.57 54898.23 24.09 11.79 2.59 0.07 34.18 drbd0 0.00 0.00 0.00 2849.34 0.00 25360.30 17.80 16.19 6.15 0.25 70.70 drbd0 0.00 0.00 0.00 3261.96 0.00 33731.76 20.68 4.89 1.78 0.16 51.76 drbd0 0.00 0.00 0.00 2043.52 0.00 30833.33 30.18 0.50 0.26 0.09 18.89 drbd0 0.00 0.00 0.00 4215.49 0.00 48196.08 22.87 13.53 3.03 0.12 51.37 drbd0 0.00 0.00 0.00 3605.38 0.00 28974.50 16.07 8.83 3.13 0.22 77.89 drbd0 0.00 0.00 0.00 2308.95 0.00 29350.97 25.42 2.99 1.38 0.17 38.72 drbd0 0.00 0.00 0.00 2628.49 0.00 35123.02 26.72 0.54 0.22 0.09 23.40 drbd0 0.00 0.00 0.00 5380.86 0.00 54895.31 20.40 17.00 3.33 0.12 66.99 drbd0 0.00 0.00 0.00 3178.64 0.00 28961.55 18.22 8.13 2.85 0.26 82.33 drbd0 0.00 0.00 0.00 2804.06 0.00 40173.31 28.65 0.34 0.12 0.07 19.73 drbd0 0.00 0.00 0.00 4493.29 0.00 49576.33 22.07 15.04 3.27 0.14 63.12 drbd0 0.00 0.00 0.00 3310.85 0.00 27405.43 16.55 9.72 3.44 0.25 82.17 drbd0 0.00 0.00 0.20 2472.67 0.79 28863.37 23.34 2.79 1.34 0.14 35.84 drbd0 0.00 0.00 0.00 2304.39 0.00 32481.68 28.19 0.58 0.25 0.10 22.14 drbd0 0.00 0.00 0.00 5572.21 0.00 59488.03 21.35 12.52 2.36 0.11 62.68 drbd0 0.00 0.00 0.00 3450.09 0.00 27968.56 16.21 8.35 2.73 0.24 81.90 drbd0 0.00 0.00 0.19 2627.34 0.76 36135.37 27.51 0.68 0.26 0.10 27.53 drbd0 0.00 0.00 0.20 5086.27 0.78 61538.04 24.20 10.81 2.13 0.08 41.57 drbd0 0.00 0.00 0.00 3414.10 0.00 27194.67 15.93 12.23 3.86 0.25 87.05 drbd0 0.00 0.00 0.00 2621.64 0.00 30576.00 23.33 6.37 2.71 0.19 49.64 drbd0 0.00 0.00 0.00 2312.89 0.00 32974.22 28.51 0.70 0.30 0.12 27.15 drbd0 0.00 0.00 0.00 4520.85 0.00 50033.20 22.13 20.79 4.71 0.13 59.85 drbd0 0.00 0.00 0.40 4137.52 1.60 37271.06 18.02 9.56 2.62 0.21 86.43 drbd0 0.00 0.00 0.00 2460.08 0.00 30514.17 24.81 2.42 1.11 0.21 50.70 drbd0 0.00 0.00 0.20 3989.17 0.79 48795.28 24.46 12.05 2.90 0.10 39.37 drbd0 0.00 0.00 0.00 4282.18 0.00 39978.61 18.67 14.16 3.70 0.21 90.69 drbd0 0.00 0.00 0.00 3468.18 0.00 39852.17 22.98 8.66 2.70 0.23 78.46 drbd0 0.00 0.00 0.00 2629.47 0.00 38732.42 29.46 0.38 0.15 0.07 19.45 drbd0 0.00 0.00 0.00 4976.03 0.00 55009.82 22.11 13.02 2.79 0.11 56.19 drbd0 0.00 0.00 0.00 3465.76 0.00 28721.40 16.57 11.06 3.45 0.23 79.18 drbd0 0.00 0.00 0.00 3433.27 0.00 39198.44 22.83 3.31 1.14 0.13 44.75 drbd0 0.00 0.00 0.00 4003.50 0.00 47852.92 23.91 9.46 2.39 0.07 27.43 drbd0 0.00 0.00 0.00 4438.28 0.00 37784.38 17.03 14.62 3.56 0.19 82.62 drbd0 0.00 0.00 0.00 3758.57 0.00 35619.92 18.95 5.58 1.75 0.19 71.91 Cheers, -- Casey Allen Shobe Database Architect, The Berkeley Electronic Press cshobe at bepress.com (email/jabber/aim/msn) http://www.bepress.com | +1 (510) 665-1200 x163