What is IOPS and how to calculate.

[senthil_kumar_1]

Hi All,

I have some questions above IOPS.

1)What is IOPS?

2)How to calculate?

3)How it affects system performance?

[Uwe Zessin]

IOPS is short for Input/Output Operations (=reads/writes) per second.

You cannot really calculate it, because the number depends on a lot of factors, e.g.
- the size of the transfer

- the relative locality of the I/O requests
-- a low locality means high seek distances for the read/write heads which requires time not available to transfer data

If a device can do many I/Os (because it rotates faster than another one or is smaller and thus as smaller move distances) it gets the job done more quickly. The faster you work - the more money you can make (often ;-).

[senthil_kumar_1]

Could any one of you clarify further?

[Greybeard · Accepted solution]

http://en.wikipedia.org/wiki/IOPS

[senthil_kumar_1]

Hi All,

I came across iozone.

I have one linux server running on VMware. the disk to VMware comes from NFS of NetApp.

Now I have ran following command to generate IOPS reports.

# /opt/iozone/bin/iozone -Ra -g 2G
Iozone: Performance Test of File I/O
Version $Revision: 3.303 $
Compiled for 32 bit mode.
Build: linux

Contributors:William Norcott, Don Capps, Isom Crawford, Kirby Collins
Al Slater, Scott Rhine, Mike Wisner, Ken Goss
Steve Landherr, Brad Smith, Mark Kelly, Dr. Alain CYR,
Randy Dunlap, Mark Montague, Dan Million,
Jean-Marc Zucconi, Jeff Blomberg, Benny Halevy,
Erik Habbinga, Kris Strecker, Walter Wong, Joshua Root.

Run began: Tue Jul 20 08:09:00 2010

Excel chart generation enabled
Auto Mode
Using maximum file size of 2097152 kilobytes.
Command line used: /opt/iozone/bin/iozone -Ra -g 2G
Output is in Kbytes/sec
Time Resolution = 0.000004 seconds.
Processor cache size set to 1024 Kbytes.
Processor cache line size set to 32 bytes.
File stride size set to 17 * record size.
random random bkwd record stride
KB reclen write rewrite read reread read write read rewrite read fwrite frewrite fread freread
64 4 127223 524892 939941 1596038 914285 680851 752941 719876 831988 191044 646464 1000001 1280001
64 8 228484 435644 1030471 2212072 1279998 646464 1066668 955168 1484389 271186 820513 1641026 2064521
64 16 225301 810740 1834688 2663710 1729731 1032257 864864 875426 1600275 261224 927535 1454544 2461538
64 32 230164 876336 2140624 2789672 2064513 1185185 842104 429717 1161713 310679 1333332 1939391 2782611
64 64 194461 800028 2006647 3060621 2461538 1207547 1729731 1228479 2065250 303317 876712 864864 2909095
128 4 146122 633646 1094148 1598526 969697 656410 842105 752413 901866 212978 627451 825806 1094017
128 8 301930 969990 1779705 2248562 1471264 977099 1230769 1066673 1660602 280701 895104 1471264 2206896
128 16 348815 710679 1488682 2671581 1910448 992248 1406593 928259 1997480 266112 663212 1406593 2098359
128 32 330759 1067648 2327342 2972968 2327273 1267326 1174311 1162958 1580934 401253 1084745 1207546 2909089
128 64 330834 999372 1752781 3197153 2723401 1347367 1969232 1376791 2558876 323232 962406 1242718 1406593
128 128 265496 1173763 2668430 3462873 2909089 1454545 2245614 1436640 2784086 350684 888888 2612248 2909089
256 4 194239 709208 1361135 1480408 911031 717086 937728 771034 984513 222029 636815 1286431 1319587
256 8 317648 1080199 1954228 2267096 1532933 1015873 1354497 1089670 1515157 289592 709141 1765517 1142857
256 16 311477 810137 1969060 2585190 1999998 1142856 1684210 1196645 2065537 340878 799999 1523809 1391304
256 32 350685 1158532 2586927 3015027 2509804 1361702 1984496 1439022 2507586 416260 1174312 2370369 2976744
256 64 396957 1212785 2911906 3328856 2909090 1479769 2415093 1312077 2844616 472324 1347367 2559997 3199997
256 128 398789 1169237 1561767 1803746 3121952 1174311 2306307 1488113 2976277 378138 1242718 1590062 3459464
256 256 220900 1008091 1236765 3508494 3324673 1174312 2694735 1532793 2876185 354570 996108 2151260 3506849
512 4 207615 730398 1012053 975428 978967 644836 740955 749578 859078 288288 737752 1080168 1475504
512 8 311413 837945 1471492 2179157 1488371 909413 1051334 1057606 1190604 300822 696598 1630572 2031746
512 16 350472 791413 1376704 1610140 1695364 820512 988416 1187958 1137900 328415 718092 1523809 2547264
512 32 342720 878327 2264603 2959801 2485437 1171624 1422222 1422415 2559986 362863 1075630 1924812 2942529
512 64 346655 860381 1630192 2976956 2509804 1132743 1326425 1224917 2371265 384673 955224 1510324 1510324
512 128 337719 735675 2425512 2798426 3047618 1177011 1510324 1454297 2978448 438731 1011857 1414364 3303227
512 256 373156 965899 2381437 3529660 3368423 1224880 1700996 1488171 2752437 259898 1032258 2255506 3555556
512 512 388476 1091708 2245009 1667983 2534654 1387533 1718120 1185438 2151069 312767 1075630 2081300 3531035
1024 4 216219 701902 989480 1262542 954333 646872 641604 667484 797545 274825 629766 1036437 1214709
1024 8 271615 747961 1111753 1879050 1349143 829821 843492 1114391 1113104 385252 640801 1395095 1081309
1024 16 470606 951621 1551400 3346700 2618925 1302799 1321290 1928465 2326744 451300 945521 1718121 3093655
1024 32 527845 1270539 1942681 4013994 2639175 1651612 2178723 2035633 1718358 440809 775757 1556231 2426539
1024 64 337620 889640 1799800 2286202 2745308 1395095 1166286 1524015 2782148 284840 1247259 1151856 3240506
1024 128 492560 811379 1796390 3251642 2124481 1815602 1481910 1521408 2585988 479400 863406 1622821 2737967
1024 256 484134 1103318 1771871 3554703 2680628 1969230 1756432 1600127 2876616 336842 1073375 1689769 3075075
1024 512 394607 1096233 1928515 2521896 3093655 1311139 2111340 1570472 2813898 244858 977099 1735593 3150769
1024 1024 360809 857682 1170440 2639492 2723404 1074501 1528358 1084873 1732488 372093 847682 1335071 2202150
2048 4 275975 593813 592598 1045482 843145 639400 673241 800954 726226 276756 667971 1009861 1372654
2048 8 328894 758512 998054 1461770 1194169 803767 785878 1102785 1079031 310397 680172 1157716 1102854
2048 16 314596 973376 1329868 1468045 1237462 1021446 1173639 1317026 1272104 338680 860504 1617693 1787085
2048 32 300158 998521 1616428 2398239 2321995 1250305 1367156 1498136 1654339 291322 999511 1721008 2540942
2048 64 366105 965115 1735423 2223588 2441001 1222686 1731191 1566975 2091986 316488 917151 1678688 2367630
2048 128 379896 1048097 1606409 2314335 2441001 1311979 1651613 1705287 3319694 377025 879725 1618972 2169491
2048 256 383514 1201808 1411421 1744418 1762478 1087626 1725358 1611425 3189659 278412 706450 1468100 1753424
2048 512 312099 617603 1943186 2560023 2589127 1399863 1449398 922074 2579406 223825 691658 1015369 1963566
2048 1024 312576 849052 1593637 1870218 1988349 1157062 1375419 1274517 1879075 249118 900219 1611329 1090521
2048 2048 329261 682191 1097001 812355 1419265 1007874 1367156 652449 1216198 329366 839688 1089941 1532934
4096 4 168047 685536 949271 1142230 734445 531533 698261 818201 775161 285754 349637 977565 1196261
4096 8 295269 767316 1092572 1426689 1104936 720872 480243 1135546 944843 312862 747581 1138093 1325566
4096 16 319402 923334 1489450 2100485 1810786 1178705 1276807 2050092 1459260 434773 413570 1325566 1363061
4096 32 341019 951874 1634409 1727470 1854232 924813 1366244 1515963 1534119 310091 866878 1242718 1892791
4096 64 362445 917769 1512538 1703065 1865209 1051334 1423705 1617646 1759460 330509 871303 1482983 1997074
4096 128 346793 954351 1655591 1532334 1574173 1046767 1648953 1687682 1896376 363024 657886 1705245 1931164
4096 256 382806 907397 1710294 1358957 1973975 1108525 1465998 1696832 3346298 302936 653999 1592534 1759450
4096 512 352190 812211 1750435 1959872 1831023 1090231 1447861 1663006 2967946 269137 519138 1462334 2033763
4096 1024 354388 856012 1363967 1701727 1915809 940096 1006635 1495972 2687693 237201 440335 1129619 1484595
4096 2048 327758 676476 1329435 1261876 1646964 919622 974078 1136861 1396567 254995 677360 690841 1045965
4096 4096 300689 704495 1031723 1099867 1153802 799219 1030958 823633 1033532 334421 755162 1049987 1092558
8192 4 222089 701495 857889 1085017 808128 552468 708221 805264 743314 283754 598611 941068 957121
8192 8 305023 791274 1160844 1270857 1015747 726692 970271 1118964 1066680 316085 679552 1122038 1193647
8192 16 323461 800784 1167134 1500887 1330950 856634 950348 407078 259931 320739 697013 1218866 1453771
8192 32 359154 847423 1599404 1427898 1384485 943996 1462595 1528381 1580884 345639 795726 1372884 1681790
8192 64 364576 897457 1670444 1708773 1679376 900912 1543621 1646330 1648633 334012 806140 1626042 1641354
8192 128 290414 897860 1655304 1269680 1716680 933987 1705955 1729403 1710626 361438 837370 1514232 1639711
8192 256 355972 825721 1517321 1808375 1771243 943561 1421235 1763994 1760999 301209 577511 1387298 1735593
8192 512 345015 823141 1582711 1788614 1727176 1023872 1499542 1643346 3259872 272621 541226 1553574 1528358
8192 1024 343738 783241 1461278 1352910 1576294 814638 1487291 1668788 3221406 265982 555653 1537537 1008618
8192 2048 372584 695889 1114707 1111241 1273235 846368 1165789 1309057 1767790 309892 599268 1094309 1143176
8192 4096 410933 682101 790430 758660 903396 640050 692886 650680 800947 185486 661018 727854 712533
8192 8192 326128 499117 670155 794947 707121 584224 594700 639696 722337 312064 610432 824061 354831
16384 4 194157 634082 871398 925958 741122 529729 821170 1237545 969701 389279 705720 913724 932657
16384 8 297480 752247 1140398 1309243 1148142 724474 1083024 1604088 1015995 401519 586609 988655 1182362
16384 16 306386 394329 1284220 1375300 1217779 776382 1098196 1343163 1249544 306994 672274 1403941 1433922
16384 32 294548 839131 1301756 1390114 1513673 898147 1206036 1516879 1397824 425945 748709 1219138 1158371
16384 64 337619 853648 1309354 1579029 1447605 761161 1413632 1632522 1514949 335133 728760 1186386 1361928
16384 128 349533 817152 1379228 1551205 1600312 883234 1548289 1720639 1455593 324641 778189 1650448 1415953
16384 256 289562 833283 1730840 1458426 1438202 816871 1502705 1717415 1686796 286849 427067 1632522 1647295
16384 512 350572 840768 1640855 1581787 1670813 876665 1614028 1759439 1777991 289383 588569 1595170 1736144


My Questions:

1)How to analyse the above report?

2)How to find all IOPS given above are optimum?