{"id":83,"date":"2011-03-02T09:38:43","date_gmt":"2011-03-02T01:38:43","guid":{"rendered":"http:\/\/ipcpu.sa.cy.com\/?p=83"},"modified":"2011-03-02T09:38:43","modified_gmt":"2011-03-02T01:38:43","slug":"linux-study-iostat","status":"publish","type":"post","link":"https:\/\/c.ipcpu.com\/2011\/03\/linux-study-iostat\/","title":{"rendered":"Linux iostat\u76d1\u6d4bIO\u72b6\u6001"},"content":{"rendered":"

\u672c\u6587\u6700\u540e\u4e00\u6b21\u4fee\u6539\u65f6\u95f4 2011-07-18 15\uff1a47<\/span><\/p>\n

Linux\u7cfb\u7edf\u51fa\u73b0\u4e86\u6027\u80fd\u95ee\u9898\uff0c\u4e00\u822c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7top\u3001iostat\u3001free\u3001vmstat\u7b49\u547d\u4ee4\u6765\u67e5\u770b\u521d\u6b65\u5b9a\u4f4d\u95ee\u9898\u3002\u5176\u4e2diostat\u53ef\u4ee5\u7ed9\u6211\u4eec\u63d0\u4f9b\u4e30\u5bcc\u7684IO\u72b6\u6001\u6570\u636e\u3002<\/p>\n

iostat\u5c5e\u4e8esysstat\u8f6f\u4ef6\u5305\u3002\u53ef\u4ee5\u7528yum install sysstat \u76f4\u63a5\u5b89\u88c5\u3002<\/p>\n

Sysstat \u8f6f\u4ef6\u5305\u96c6\u6210\u5982\u4e0b\u5de5\u5177\uff1a<\/p>\n

* iostat \u5de5\u5177\u63d0\u4f9bCPU\u4f7f\u7528\u7387\u53ca\u786c\u76d8\u541e\u5410\u6548\u7387\u7684\u6570\u636e\uff1b
\n* mpstat \u5de5\u5177\u63d0\u4f9b\u5355\u4e2a\u5904\u7406\u5668\u6216\u591a\u4e2a\u5904\u7406\u5668\u76f8\u5173\u6570\u636e\uff1b
\n* sar \u5de5\u5177\u8d1f\u8d23\u6536\u96c6\u3001\u62a5\u544a\u5e76\u5b58\u50a8\u7cfb\u7edf\u6d3b\u8dc3\u7684\u4fe1\u606f\uff1b
\n* sa1 \u5de5\u5177\u8d1f\u8d23\u6536\u96c6\u5e76\u5b58\u50a8\u6bcf\u5929\u7cfb\u7edf\u52a8\u6001\u4fe1\u606f\u5230\u4e00\u4e2a\u4e8c\u8fdb\u5236\u7684\u6587\u4ef6\u4e2d\u3002\u5b83\u662f\u901a\u8fc7\u8ba1\u5212\u4efb\u52a1\u5de5\u5177cron\u6765\u8fd0\u884c\uff0c\u662f\u4e3asadc\u6240\u8bbe\u8ba1\u7684\u7a0b\u5e8f\u524d\u7aef\u7a0b\u5e8f\uff1b
\n* sa2 \u5de5\u5177\u8d1f\u8d23\u628a\u6bcf\u5929\u7684\u7cfb\u7edf\u6d3b\u8dc3\u6027\u606f\u5199\u5165\u603b\u7ed3\u6027\u7684\u62a5\u544a\u4e2d\u3002\u5b83\u662f\u4e3asar\u6240\u8bbe\u8ba1\u7684\u524d\u7aef \uff0c\u8981\u901a\u8fc7cron\u6765\u8c03\u7528
\n* sadc \u662f\u7cfb\u7edf\u52a8\u6001\u6570\u636e\u6536\u96c6\u5de5\u5177\uff0c\u6536\u96c6\u7684\u6570\u636e\u88ab\u5199\u4e00\u4e2a\u4e8c\u8fdb\u5236\u7684\u6587\u4ef6\u4e2d\uff0c\u5b83\u88ab\u7528\u4f5csar\u5de5\u5177\u7684\u540e\u7aef\uff1b
\n* sadf \u663e\u793a\u88absar\u901a\u8fc7\u591a\u79cd\u683c\u5f0f\u6536\u96c6\u7684\u6570\u636e\uff1b<\/p>\n

1. \u57fa\u672c\u4f7f\u7528<\/strong><\/span><\/p>\n

$iostat<\/span> -<\/span>d -<\/span>k 1<\/span> 10<\/span><\/pre>\n
\u53c2\u6570 -d \u8868\u793a\uff0c\u663e\u793a\u8bbe\u5907\uff08\u78c1\u76d8\uff09\u4f7f\u7528\u72b6\u6001\uff1b-k\u67d0\u4e9b\u4f7f\u7528block\u4e3a\u5355\u4f4d\u7684\u5217\u5f3a\u5236\u4f7f\u7528Kilobytes\u4e3a\u5355\u4f4d\uff1b1 10\u8868\u793a\uff0c\u6570\u636e\u663e\u793a\u6bcf\u96941\u79d2\u5237\u65b0\u4e00\u6b21\uff0c\u5171\u663e\u793a10\u6b21\u3002<\/span><\/p>\n
$iostat<\/span> -<\/span>d -<\/span>k 1<\/span> 10<\/span>\nDevice:<\/span> tps kB_read\/<\/span>s kB_wrtn\/<\/span>s kB_read kB_wrtn\nsda 39.29<\/span> 21.14<\/span> 1.44<\/span> 441339807<\/span> 29990031<\/span>\nsda1 0.00<\/span> 0.00<\/span> 0.00<\/span> 1623<\/span> 523<\/span>\nsda2 1.32<\/span> 1.43<\/span> 4.54<\/span> 29834273<\/span> 94827104<\/span>\nsda3 6.30<\/span> 0.85<\/span> 24.95<\/span> 17816289<\/span> 520725244<\/span>\nsda5 0.85<\/span> 0.46<\/span> 3.40<\/span> 9543503<\/span> 70970116<\/span>\nsda6 0.00<\/span> 0.00<\/span> 0.00<\/span> 550<\/span> 236<\/span>\nsda7 0.00<\/span> 0.00<\/span> 0.00<\/span> 406<\/span> 0<\/span>\nsda8 0.00<\/span> 0.00<\/span> 0.00<\/span> 406<\/span> 0<\/span>\nsda9 0.00<\/span> 0.00<\/span> 0.00<\/span> 406<\/span> 0<\/span>\nsda10 60.68<\/span> 18.35<\/span> 71.43<\/span> 383002263<\/span> 1490928140<\/span>\n\u00a0\nDevice:<\/span> tps kB_read\/<\/span>s kB_wrtn\/<\/span>s kB_read kB_wrtn\nsda 327.55<\/span> 5159.18<\/span> 102.04<\/span> 5056<\/span> 100<\/span>\nsda1 0.00<\/span> 0.00<\/span> 0.00<\/span> 0<\/span> 0<\/span><<\/span>span id=<\/span>\"more-998\"<\/span>><\/<\/span>span><\/span><\/pre>\n
\u89e3\u91ca\uff1a<\/strong>
tps<\/span>\uff1a\u8868\u793a\u6bcf\u79d2\u949f\u8f93\u51fa\u5230\u7269\u7406\u78c1\u76d8\u7684\u4f20\u8f93\u6b21\u6570\u3002\u4e00\u6b21\u4f20\u8f93\u5c31\u662f\u4e00\u4e2a\u5bf9\u7269\u7406\u78c1\u76d8\u7684 I\/O \u8bf7\u6c42\u3002\u591a\u4e2a\u903b\u8f91\u8bf7\u6c42\u53ef\u88ab\u5e76\u4e3a\u5bf9\u78c1\u76d8\u7684\u4e00\u4e2a\u5355\u4e00 I\uff0fO \u8bf7\u6c42\u3002<\/span>
kB_read\/s<\/span>\uff1a\u6bcf\u79d2\u4ece\u8bbe\u5907\uff08drive expressed\uff09\u8bfb\u53d6\u7684\u6570\u636e\u91cf\uff1b<\/span>
\nkB_wrtn\/s<\/span>\uff1a\u6bcf\u79d2\u5411\u8bbe\u5907\uff08drive expressed\uff09\u5199\u5165\u7684\u6570\u636e\u91cf\uff1b<\/span>
kB_read<\/span>\uff1a\u8bfb\u53d6\u7684\u603b\u6570\u636e\u91cf\uff1b<\/span>
\nkB_wrtn<\/span>\uff1a\u5199\u5165\u7684\u603b\u6570\u91cf\u6570\u636e\u91cf\uff1b\u8fd9\u4e9b\u5355\u4f4d\u90fd\u4e3aKilobytes\u3002<\/span>
\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u770b\u5230\u78c1\u76d8sda\u4ee5\u53ca\u5b83\u7684\u5404\u4e2a\u5206\u533a\u7684\u7edf\u8ba1\u6570\u636e\uff0c\u5f53\u65f6\u7edf\u8ba1\u7684\u78c1\u76d8\u603bTPS\u662f39.29\uff0c\u4e0b\u9762\u662f\u5404\u4e2a\u5206\u533a\u7684TPS\u3002\uff08\u56e0\u4e3a\u662f\u77ac\u95f4\u503c\uff0c\u6240\u4ee5\u603bTPS\u5e76\u4e0d\u4e25\u683c\u7b49\u4e8e\u5404\u4e2a\u5206\u533aTPS\u7684\u603b\u548c\uff09<\/span><\/p>\n
2. -x \u53c2\u6570<\/span><\/strong>
\u4f7f\u7528-x\u53c2\u6570\u6211\u4eec\u53ef\u4ee5\u83b7\u5f97\u66f4\u591a\u7edf\u8ba1\u4fe1\u606f\u3002<\/span><\/p>\n
iostat -<\/span>d -<\/span>x -<\/span>k 1<\/span> 10<\/span>\nDevice:<\/span> rrqm\/<\/span>s wrqm\/<\/span>s <<\/span>span style=<\/span>\"color: #00ff00;\"<\/span>><\/span>r\/<\/span>s w\/<\/span>s<\/<\/span>span><\/span> rsec\/<\/span>s wsec\/<\/span>s rkB\/<\/span>s wkB\/<\/span>s avgrq-<\/span>sz avgqu-<\/span>sz <<\/span>span style=<\/span>\"color: #00ff00;\"<\/span>><\/span>await svctm %<\/span>util<\/<\/span>span><\/span>\nsda 1.56<\/span> 28.31<\/span> <<\/span>span style=<\/span>\"color: #00ff00;\"<\/span>><\/span>7.80<\/span> 31.49<\/span><\/<\/span>span><\/span> 42.51<\/span> 2.92<\/span> 21.26<\/span> 1.46<\/span> 1.16<\/span> 0.03<\/span> <<\/span>span style=<\/span>\"color: #00ff00;\"<\/span>><\/span>0.79<\/span> 2.62<\/span> 10.28<\/span><\/<\/span>span><\/span>\nDevice:<\/span> rrqm\/<\/span>s wrqm\/<\/span>s <<\/span>span style=<\/span>\"color: #00ff00;\"<\/span>><\/span>r\/<\/span>s w\/<\/span>s<\/<\/span>span><\/span> rsec\/<\/span>s wsec\/<\/span>s rkB\/<\/span>s wkB\/<\/span>s avgrq-<\/span>sz avgqu-<\/span>sz <<\/span>span style=<\/span>\"color: #00ff00;\"<\/span>><\/span>await svctm %<\/span>util<\/<\/span>span><\/span>\nsda 2.00<\/span> 20.00<\/span> <<\/span>span style=<\/span>\"color: #00ff00;\"<\/span>><\/span>381.00<\/span> 7.00<\/span><\/<\/span>span><\/span> 12320.00<\/span> 216.00<\/span> 6160.00<\/span> 108.00<\/span> 32.31<\/span> 1.75<\/span> <<\/span>span style=<\/span>\"color: #00ff00;\"<\/span>><\/span>4.50<\/span> 2.17<\/span> 84.20<\/span><\/<\/span>span><\/span><\/pre>\n
rrqm\/s<\/span>:<\/strong>\u00a0<\/span>\u6bcf\u79d2\u8fdb\u884c merge \u7684\u8bfb\u64cd\u4f5c\u6570\u76ee\u3002
\nwrqm\/s<\/span>:<\/strong>\u00a0<\/span>\u6bcf\u79d2\u8fdb\u884c merge \u7684\u5199\u64cd\u4f5c\u6570\u76ee\u3002
\nr\/s:<\/strong><\/span>\u00a0<\/span>\u6bcf\u79d2\u5b8c\u6210\u7684\u8bfb I\/O \u8bbe\u5907\u6b21\u6570\u3002
\nw\/s<\/span>:<\/strong>\u00a0<\/span>\u6bcf\u79d2\u5b8c\u6210\u7684\u5199 I\/O \u8bbe\u5907\u6b21\u6570\u3002
\nrsec\/s<\/span>:<\/strong>\u00a0<\/span>\u6bcf\u79d2\u8bfb\u6247\u533a\u6570\u3002
\nwsec\/s<\/span>:\u00a0<\/span><\/strong>\u6bcf\u79d2\u5199\u6247\u533a\u6570\u3002
\nrkB\/s<\/span>:\u00a0<\/span><\/strong>\u6bcf\u79d2\u8bfbK\u5b57\u8282\u6570\u3002\u662f rsect\/s \u7684\u4e00\u534a\uff0c\u56e0\u4e3a\u6bcf\u6247\u533a\u5927\u5c0f\u4e3a512\u5b57\u8282\u3002(\u9700\u8981\u8ba1\u7b97)
\nwkB\/s<\/span>:<\/strong>\u00a0<\/span>\u6bcf\u79d2\u5199K\u5b57\u8282\u6570\u3002\u662f wsect\/s \u7684\u4e00\u534a\u3002(\u9700\u8981\u8ba1\u7b97)
\navgrq-sz<\/span>:\u00a0<\/span><\/strong>\u5e73\u5747\u6bcf\u6b21\u8bbe\u5907I\/O\u64cd\u4f5c\u7684\u6570\u636e\u5927\u5c0f (\u6247\u533a)\u3002
\navgqu-sz<\/span>:<\/strong>\u00a0<\/span>\u5e73\u5747I\/O\u961f\u5217\u957f\u5ea6\u3002
\nawait:<\/strong><\/span>\u00a0<\/span>\u5e73\u5747\u6bcf\u6b21\u8bbe\u5907I\/O\u64cd\u4f5c\u7684\u7b49\u5f85<\/span>\u65f6\u95f4 (\u6beb\u79d2)\u3002
\nsvctm<\/span>:\u00a0<\/span><\/strong>\u5e73\u5747\u6bcf\u6b21\u8bbe\u5907I\/O\u64cd\u4f5c\u7684\u670d\u52a1<\/span>\u65f6\u95f4 (\u6beb\u79d2)\u3002
\n%util<\/span>:\u00a0<\/span><\/strong>\u4e00\u79d2\u4e2d\u6709\u767e\u5206\u4e4b\u591a\u5c11\u7684\u65f6\u95f4\u7528\u4e8e I\/O \u64cd\u4f5c\u3002
\n\u5173\u4e8eMerge\u7684\u89e3\u91ca<\/strong>\uff1a\u5f53\u7cfb\u7edf\u8c03\u7528\u9700\u8981\u8bfb\u53d6\u6570\u636e\u7684\u65f6 \u5019\uff0cVFS\u5c06\u8bf7\u6c42\u53d1\u5230\u5404\u4e2aFS\uff0c\u5982\u679cFS\u53d1\u73b0\u4e0d\u540c\u7684\u8bfb\u53d6\u8bf7\u6c42\u8bfb\u53d6\u7684\u662f\u76f8\u540cBlock\u7684\u6570\u636e\uff0cFS\u4f1a\u5c06\u8fd9\u4e2a\u8bf7\u6c42\u5408\u5e76Merge<\/p>\n
await<\/span>\uff1a\u6bcf\u4e00\u4e2aIO\u8bf7\u6c42\u7684\u5904\u7406\u7684\u5e73\u5747\u65f6\u95f4\uff08\u5355\u4f4d\u662f<\/del>\u6beb\u79d2\uff09\u3002\u8fd9\u91cc\u53ef\u4ee5\u7406\u89e3\u4e3aIO\u7684\u54cd\u5e94\u65f6\u95f4\uff0c\u4e00\u822c\u5730\u7cfb\u7edfIO\u54cd\u5e94\u65f6\u95f4\u5e94\u8be5\u4f4e\u4e8e5ms\uff0c\u5982\u679c\u5927\u4e8e10ms\u5c31\u6bd4\u8f83\u5927\u4e86\u3002<\/span><\/strong><\/p>\n
%util<\/span>\uff1a\u5728\u7edf\u8ba1\u65f6\u95f4\u5185\u6240\u6709\u5904\u7406IO\u65f6\u95f4\uff0c\u9664\u4ee5\u603b\u5171\u7edf\u8ba1\u65f6\u95f4\u3002\u4f8b\u5982\uff0c\u5982\u679c \u7edf\u8ba1\u95f4\u96941\u79d2\uff0c\u8be5 \u8bbe\u5907\u67090.8\u79d2\u5728\u5904\u7406IO\uff0c\u800c0.2\u79d2\u95f2\u7f6e\uff0c\u90a3\u4e48\u8be5\u8bbe\u5907\u7684%util = 0.8\/1 = 80%\uff0c\u6240\u4ee5\u8be5\u53c2\u6570\u6697\u793a\u4e86\u8bbe\u5907\u7684\u7e41\u5fd9\u7a0b\u5ea6\u3002\u4e00\u822c\u5730\uff0c\u5982\u679c\u8be5\u53c2\u6570\u662f100%\u8868\u793a\u8bbe\u5907\u5df2\u7ecf\u63a5\u8fd1\u6ee1\u8d1f\u8377\u8fd0\u884c\u4e86\uff08\u5f53\u7136\u5982\u679c\u662f\u591a\u78c1\u76d8\uff0c\u5373\u4f7f%util\u662f100%\uff0c\u56e0 \u4e3a\u78c1\u76d8\u7684\u5e76\u53d1\u80fd\u529b\uff0c\u6240\u4ee5\u78c1\u76d8\u4f7f\u7528\u672a\u5fc5\u5c31\u5230\u4e86\u74f6\u9888\uff09\u3002<\/p>\n
3. -c \u53c2\u6570<\/span><\/strong><\/p>\n
iostat\u8fd8\u53ef\u4ee5\u7528\u6765\u83b7\u53d6cpu\u90e8\u5206\u72b6\u6001\u503c\uff1a<\/p>\n
$iostat<\/span> -<\/span>c 1<\/span> 10<\/span>\navg-<\/span>cpu:<\/span> %<\/span>user %<\/span>nice %<\/span>sys %<\/span>iowait %<\/span>idle\n1.98<\/span> 0.00<\/span> 0.35<\/span> 11.45<\/span> 86.22<\/span>\navg-<\/span>cpu:<\/span> %<\/span>user %<\/span>nice %<\/span>sys %<\/span>iowait %<\/span>idle\n1.62<\/span> 0.00<\/span> 0.25<\/span> 34.46<\/span> 63.67<\/span><\/pre>\n
4. \u5e38\u89c1\u7528\u6cd5<\/span><\/strong><\/p>\n
$iostat<\/span> -<\/span>d -<\/span>k 1<\/span> 10<\/span> #\u67e5\u770bTPS\u548c\u541e\u5410\u91cf\u4fe1\u606f\n<\/span>$iostat<\/span> -<\/span>d -<\/span>x -<\/span>k 1<\/span> 10<\/span> #\u67e5\u770b\u8bbe\u5907\u4f7f\u7528\u7387\uff08%util\uff09\u3001\u54cd\u5e94\u65f6\u95f4\uff08await\uff09\n<\/span>$iostat<\/span> -<\/span>c 1<\/span> 10<\/span> #\u67e5\u770bcpu\u72b6\u6001<\/span><\/pre>\n
5. \u5b9e\u4f8b\u5206\u6790<\/strong><\/p>\n
#iostat -d -k 1 |grep sda10\n<\/span>Device:<\/span> tps kB_read\/<\/span>s kB_wrtn\/<\/span>s kB_read kB_wrtn\nsda10 60.72<\/span> 18.95<\/span> 71.53<\/span> 395637647<\/span> 1493241908<\/span>\nsda10 299.02<\/span> 4266.67<\/span> 129.41<\/span> 4352<\/span> 132<\/span>\nsda10 483.84<\/span> 4589.90<\/span> 4117.17<\/span> 4544<\/span> 4076<\/span>\nsda10 218.00<\/span> 3360.00<\/span> 100.00<\/span> 3360<\/span> 100<\/span>\nsda10 546.00<\/span> 8784.00<\/span> 124.00<\/span> 8784<\/span> 124<\/span>\nsda10 827.00<\/span> 13232.00<\/span> 136.00<\/span> 13232<\/span> 136<\/span><\/pre>\n
\u4e0a\u9762\u770b\u5230\uff0c\u78c1\u76d8\u6bcf\u79d2\u4f20\u8f93\u6b21\u6570\u5e73\u5747\u7ea6400\uff1b\u6bcf\u79d2\u78c1\u76d8\u8bfb\u53d6\u7ea65MB\uff0c\u5199\u5165\u7ea61MB\u3002<\/span><\/p>\n
#iostat -d -x -k 1\n<\/span>Device:<\/span> rrqm\/<\/span>s wrqm\/<\/span>s r\/<\/span>s w\/<\/span>s rsec\/<\/span>s wsec\/<\/span>s rkB\/<\/span>s wkB\/<\/span>s avgrq-<\/span>sz avgqu-<\/span>sz await svctm %<\/span>util\nsda 1.56<\/span> 28.31<\/span> 7.84<\/span> 31.50<\/span> 43.65<\/span> 3.16<\/span> 21.82<\/span> 1.58<\/span> 1.19<\/span> 0.03<\/span> 0.80<\/span> 2.61<\/span> 10.29<\/span>\nsda 1.98<\/span> 24.75<\/span> 419.80<\/span> 6.93<\/span> 13465.35<\/span> 253.47<\/span> 6732.67<\/span> 126.73<\/span> 32.15<\/span> 2.00<\/span> 4.70<\/span> 2.00<\/span> 85.25<\/span>\nsda 3.06<\/span> 41.84<\/span> 444.90<\/span> 54.08<\/span> 14204.08<\/span> 2048.98<\/span> 7102.04<\/span> 1024.49<\/span> 32.57<\/span> 2.10<\/span> 4.21<\/span> 1.85<\/span> 92.24<\/span><\/pre>\n
\u53ef\u4ee5\u770b\u5230\u78c1\u76d8\u7684\u5e73\u5747\u54cd\u5e94\u65f6\u95f4<5ms\uff0c\u78c1\u76d8\u4f7f\u7528\u7387>80\u3002\u78c1\u76d8\u54cd\u5e94\u6b63\u5e38\uff0c\u4f46\u662f\u5df2\u7ecf\u5f88\u7e41\u5fd9\u4e86\u3002<\/p>\n
svctm \u4e00\u822c\u8981\u5c0f\u4e8e await<\/strong>\u00a0<\/span>(\u56e0\u4e3a\u540c\u65f6\u7b49\u5f85\u7684\u8bf7\u6c42\u7684\u7b49\u5f85\u65f6\u95f4\u88ab\u91cd\u590d\u8ba1\u7b97\u4e86)\uff0csvctm \u7684\u5927\u5c0f\u4e00\u822c\u548c\u78c1\u76d8\u6027\u80fd\u6709\u5173\uff0cCPU\/\u5185\u5b58\u7684\u8d1f\u8377\u4e5f\u4f1a\u5bf9\u5176\u6709\u5f71\u54cd\uff0c\u8bf7\u6c42\u8fc7\u591a\u4e5f\u4f1a\u95f4\u63a5\u5bfc\u81f4 svctm \u7684\u589e\u52a0\u3002await \u7684\u5927\u5c0f\u4e00\u822c\u53d6\u51b3\u4e8e\u670d\u52a1\u65f6\u95f4(svctm) \u4ee5\u53ca I\/O \u961f\u5217\u7684\u957f\u5ea6\u548c I\/O \u8bf7\u6c42\u7684\u53d1\u51fa\u6a21\u5f0f\u3002\u5982\u679c svctm \u6bd4\u8f83\u63a5\u8fd1 await\uff0c\u8bf4\u660e I\/O \u51e0\u4e4e\u6ca1\u6709\u7b49\u5f85\u65f6\u95f4\uff1b\u5982\u679c await \u8fdc\u5927\u4e8e svctm\uff0c\u8bf4\u660e I\/O \u961f\u5217\u592a\u957f\uff0c\u5e94\u7528\u5f97\u5230\u7684\u54cd\u5e94\u65f6\u95f4\u53d8\u6162\uff0c\u5982\u679c\u54cd\u5e94\u65f6\u95f4\u8d85\u8fc7\u4e86\u7528\u6237\u53ef\u4ee5\u5bb9\u8bb8\u7684\u8303\u56f4\uff0c\u8fd9\u65f6\u53ef\u4ee5\u8003\u8651\u66f4\u6362\u66f4\u5feb\u7684\u78c1\u76d8\uff0c\u8c03\u6574\u5185\u6838 elevator \u7b97\u6cd5\uff0c\u4f18\u5316\u5e94\u7528\uff0c\u6216\u8005\u5347\u7ea7 CPU\u3002<\/span>
\n
\n\u4e0b\u9762\u662f\u522b\u4eba\u5199\u7684\u8fd9\u4e2a\u53c2\u6570\u8f93\u51fa\u7684\u5206\u6790<\/strong><\/p>\n
\n
\n
iostat -x 1\navg-cpu: %user %nice %sys %idle\n16.24 0.00 4.31 79.44\nDevice: rrqm\/s wrqm\/s <span style=\"color: #00ff00;\">r\/s w\/s<\/span> rsec\/s wsec\/s rkB\/s wkB\/s avgrq-sz avgqu-sz <span style=\"color: #00ff00;\">await svctm %util<\/span>\n\/dev\/cciss\/c0d0\n0.00 44.90 1.02 <span style=\"color: #00ff00;\">27.55 8.16<\/span> 579.59 4.08 289.80 20.57 22.35 <span style=\"color: #00ff00;\">78.21 5.00 14.29<\/span><\/pre>\n<\/div>\n
\n
\u4e0a\u9762\u7684 iostat \u8f93\u51fa\u8868\u660e\u79d2\u6709 28.57 \u6b21\u8bbe\u5907 I\/O \u64cd\u4f5c: \u603bIO(io)\/s = r\/s(\u8bfb) +w\/s(\u5199) = 1.02+27.55 = 28.57 (\u6b21\/\u79d2) \u5176\u4e2d\u5199\u64cd\u4f5c\u5360\u4e86\u4e3b\u4f53 (w:r = 27:1)\u3002<\/p>\n
\u5e73\u5747\u6bcf\u6b21\u8bbe\u5907 I\/O \u64cd\u4f5c\u53ea\u9700\u8981 5ms \u5c31\u53ef\u4ee5\u5b8c\u6210\uff0c\u4f46\u6bcf\u4e2a I\/O \u8bf7\u6c42\u5374\u9700\u8981\u7b49\u4e0a 78ms\uff0c\u4e3a\u4ec0\u4e48? \u56e0\u4e3a\u53d1\u51fa\u7684 I\/O \u8bf7\u6c42\u592a\u591a (\u6bcf\u79d2\u949f\u7ea6 29 \u4e2a)\uff0c\u5047\u8bbe\u8fd9\u4e9b\u8bf7\u6c42\u662f\u540c\u65f6\u53d1\u51fa\u7684\uff0c\u90a3\u4e48\u5e73\u5747\u7b49\u5f85\u65f6\u95f4\u53ef\u4ee5\u8fd9\u6837\u8ba1\u7b97:<\/p>\n
\u5e73\u5747\u7b49\u5f85\u65f6\u95f4 = \u5355\u4e2a I\/O \u670d\u52a1\u65f6\u95f4 * ( 1 + 2 + \u2026 + \u8bf7\u6c42\u603b\u6570-1) \/ \u8bf7\u6c42\u603b\u6570<\/p>\n
\u5e94\u7528\u5230\u4e0a\u9762\u7684\u4f8b\u5b50: \u5e73\u5747\u7b49\u5f85\u65f6\u95f4 = 5ms * (1+2+\u2026+28)\/29 = 70ms\uff0c\u548c iostat \u7ed9\u51fa\u768478ms \u7684\u5e73\u5747\u7b49\u5f85\u65f6\u95f4\u5f88\u63a5\u8fd1\u3002\u8fd9\u53cd\u8fc7\u6765\u8868\u660e I\/O \u662f\u540c\u65f6\u53d1\u8d77\u7684\u3002<\/p>\n
\u6bcf\u79d2\u53d1\u51fa\u7684 I\/O \u8bf7\u6c42\u5f88\u591a (\u7ea6 29 \u4e2a)\uff0c\u5e73\u5747\u961f\u5217\u5374\u4e0d\u957f (\u53ea\u6709 2 \u4e2a \u5de6\u53f3)\uff0c\u8fd9\u8868\u660e\u8fd9 29 \u4e2a\u8bf7\u6c42\u7684\u5230\u6765\u5e76\u4e0d\u5747\u5300\uff0c\u5927\u90e8\u5206\u65f6\u95f4 I\/O \u662f\u7a7a\u95f2\u7684\u3002<\/p>\n
\u4e00\u79d2\u4e2d\u6709 14.29% \u7684\u65f6\u95f4 I\/O \u961f\u5217\u4e2d\u662f\u6709\u8bf7\u6c42\u7684\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c85.71% \u7684\u65f6\u95f4\u91cc I\/O \u7cfb\u7edf\u65e0\u4e8b\u53ef\u505a\uff0c\u6240\u6709 29 \u4e2a I\/O \u8bf7\u6c42\u90fd\u5728142\u6beb\u79d2\u4e4b\u5185\u5904\u7406\u6389\u4e86\u3002<\/p>\n
delta(ruse+wuse)\/delta(io) = await = 78.21 => delta(ruse+wuse)\/s =78.21 * delta(io)\/s = 78.21*28.57 = 2232.8\uff0c\u8868\u660e\u6bcf\u79d2\u5185\u7684I\/O\u8bf7\u6c42\u603b\u5171\u9700\u8981\u7b49\u5f852232.8ms\u3002\u6240\u4ee5\u5e73\u5747\u961f\u5217\u957f\u5ea6\u5e94\u4e3a 2232.8ms\/1000ms = 2.23\uff0c\u800c iostat \u7ed9\u51fa\u7684\u5e73\u5747\u961f\u5217\u957f\u5ea6 (avgqu-sz) \u5374\u4e3a 22.35\uff0c\u4e3a\u4ec0\u4e48?! \u56e0\u4e3a iostat \u4e2d\u6709 bug\uff0cavgqu-sz \u503c\u5e94\u4e3a 2.23\uff0c\u800c\u4e0d\u662f 22.35\u3002<\/p>\n
\u53c2\u8003\u8d44\u6599\uff1a<\/strong><\/p>\n
http:\/\/www.orczhou.com\/index.php\/2010\/03\/iostat-detail\/<\/p>\n
http:\/\/www.php-oa.com\/2009\/02\/03\/iostat.html<\/p>\n
http:\/\/www.51testing.com\/?uid-159438-action-viewspace-itemid-108553<\/p>\n<\/div>\n<\/div>\n
\u7cbe\u5f69\u8bc4\u8bba\uff1a<\/p>\n
\u00a0\u6212\u5f80 | #1
\nMay 29, 2011 at 1:06 pm
\n\u6211\u4e00\u822c\u662f\u7528top\u770b\u770bwa%\u662f\u591a\u5c11.
\n\u7528\u8fd9\u4e2a\u597d\u50cf\u53ea\u80fd\u770b\u5230\u6bcf\u4e2a\u786c\u76d8IO\u6709\u591a\u5c11,\u8fd8\u662f\u65e0\u6cd5\u67e5\u770b\u67d0\u4e2a\u8fdb\u7a0b\u7684IO\u5360\u7528?
\nperfgeeks | #2
\nDecember 2, 2011 at 2:21 pm
\n#1
\niostat\u7edf\u8ba1\u7684\u662f\u78c1\u76d8\u8bbe\u7f6e\u3002\u8fdb\u7a0b\u8fdb\u884c\u7684IO\uff0c\u6bd4\u5982\u7f51\u7edcIO\uff0c\u78c1\u76d8IO(read(),write()\uff0cfsync())\u5e76\u4e0d\u80fd\u901a\u8fc7iostat \u7edf\u8ba1\u3002Linux\u4e3a\u4e86\u5feb\u901f\u54cd\u5e94\u8fdb\u7a0b\uff0c\u4f7f\u7528OS page cache\uff0c\u591a\u6b21write()\uff0c\u6709\u53ef\u80fd\u5408\u5e76\u6210\u4e00\u6b21disk\u8bf7\u6c42\u3002\u5373read()\/write()\u903b\u8f91\u8bf7\u6c42\uff0c\u5408\u5e76\u540e\u8fdb\u884cdisk\u8bf7\u6c42\uff0c\u624d\u662f\u6b64\u6587\u8bf4\u7684\u8bbe\u5907\u8bf7 \u6c42\u3002\u4e0d\u901a\uff0c\u53ef\u4ee5\u901a\u8fc7strace\u8fdb\u884c\u8fdb\u7a0bIO\u7edf\u8ba1\u3002<\/p>\n
=====<\/p>\n
\u672c\u6587\u6062\u590d\u81ea\u5feb\u7167\u3002<\/p>\n
\n
\u8f6c\u8f7d\u8bf7\u6ce8\u660e\uff1aIPCPU-\u7f51\u7edc\u4e4b\u8def<\/a> » Linux iostat\u76d1\u6d4bIO\u72b6\u6001<\/a><\/p>","protected":false},"excerpt":{"rendered":"
\u672c\u6587\u6700\u540e\u4e00\u6b21\u4fee\u6539\u65f6\u95f4 2011-07-18 15\uff1a47 Linux\u7cfb\u7edf\u51fa\u73b0\u4e86\u6027\u80fd\u95ee\u9898\uff0c\u4e00\u822c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7top\u3001iostat\u3001free\u3001vmstat\u7b49\u547d\u4ee4\u6765\u67e5\u770b\u521d\u6b65\u5b9a\u4f4d\u95ee\u9898\u3002\u5176\u4e2diostat\u53ef\u4ee5\u7ed9\u6211\u4eec\u63d0\u4f9b\u4e30\u5bcc\u7684IO\u72b6\u6001\u6570\u636e\u3002 iostat\u5c5e\u4e8esysstat\u8f6f\u4ef6\u5305\u3002\u53ef\u4ee5\u7528yum install sysstat \u76f4\u63a5\u5b89\u88c5\u3002 Sysstat \u8f6f\u4ef6\u5305\u96c6\u6210\u5982\u4e0b\u5de5\u5177\uff1a * iostat \u5de5\u5177\u63d0\u4f9bCPU\u4f7f\u7528\u7387\u53ca\u786c\u76d8\u541e\u5410\u6548\u7387\u7684\u6570\u636e\uff1b * mpstat \u5de5\u5177\u63d0\u4f9b\u5355\u4e2a\u5904\u7406\u5668\u6216\u591a\u4e2a\u5904\u7406\u5668\u76f8\u5173\u6570\u636e\uff1b * sar \u5de5\u5177\u8d1f\u8d23\u6536\u96c6\u3001\u62a5\u544a\u5e76\u5b58\u50a8\u7cfb\u7edf\u6d3b\u8dc3\u7684\u4fe1\u606f\uff1b * sa1 \u5de5\u5177\u8d1f\u8d23\u6536\u96c6\u5e76\u5b58\u50a8\u6bcf\u5929\u7cfb\u7edf\u52a8\u6001\u4fe1\u606f\u5230\u4e00\u4e2a\u4e8c\u8fdb\u5236\u7684\u6587\u4ef6\u4e2d\u3002\u5b83\u662f\u901a\u8fc7\u8ba1\u5212\u4efb\u52a1\u5de5\u5177cron\u6765\u8fd0\u884c\uff0c\u662f\u4e3asadc\u6240\u8bbe\u8ba1\u7684\u7a0b\u5e8f\u524d\u7aef\u7a0b\u5e8f\uff1b * sa2 \u5de5\u5177\u8d1f\u8d23\u628a\u6bcf\u5929\u7684\u7cfb\u7edf\u6d3b\u8dc3\u6027\u606f\u5199\u5165\u603b\u7ed3\u6027\u7684\u62a5\u544a\u4e2d\u3002\u5b83\u662f\u4e3asar\u6240\u8bbe\u8ba1\u7684\u524d\u7aef \uff0c\u8981\u901a\u8fc7cron\u6765\u8c03\u7528 * sadc \u662f\u7cfb\u7edf\u52a8\u6001\u6570\u636e\u6536\u96c6\u5de5\u5177\uff0c\u6536\u96c6\u7684\u6570\u636e\u88ab\u5199\u4e00\u4e2a\u4e8c\u8fdb\u5236\u7684\u6587\u4ef6\u4e2d\uff0c\u5b83\u88ab\u7528\u4f5csar\u5de5\u5177\u7684\u540e\u7aef\uff1b * sadf \u663e\u793a\u88absar\u901a\u8fc7\u591a\u79cd\u683c\u5f0f\u6536\u96c6\u7684\u6570\u636e\uff1b 1. \u57fa\u672c\u4f7f\u7528 $iostat -d -k 1 10 \u53c2\u6570 -d \u8868\u793a\uff0c\u663e\u793a\u8bbe\u5907\uff08\u78c1\u76d8\uff09\u4f7f\u7528\u72b6\u6001\uff1b-k\u67d0\u4e9b\u4f7f\u7528block\u4e3a\u5355\u4f4d\u7684\u5217\u5f3a\u5236\u4f7f\u7528Kilobytes\u4e3a\u5355\u4f4d\uff1b1 10\u8868\u793a\uff0c\u6570\u636e\u663e\u793a\u6bcf\u96941\u79d2\u5237\u65b0\u4e00\u6b21\uff0c\u5171\u663e\u793a10\u6b21\u3002 $iostat -d -k 1 10 Device: tps kB_read\/s kB_wrtn\/s kB_read kB_wrtn sda […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[13],"tags":[17,18],"_links":{"self":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/posts\/83"}],"collection":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/comments?post=83"}],"version-history":[{"count":0,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/posts\/83\/revisions"}],"wp:attachment":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/media?parent=83"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/categories?post=83"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/tags?post=83"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}