{"id":146,"date":"2014-08-11T09:44:56","date_gmt":"2014-08-11T01:44:56","guid":{"rendered":"http:\/\/www.codeeel.com\/?p=146"},"modified":"2014-08-11T09:44:56","modified_gmt":"2014-08-11T01:44:56","slug":"linux%e7%b3%bb%e7%bb%9f%e8%b4%9f%e8%bd%bd%e6%a3%80%e6%9f%a5%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/www.codeeel.com\/?p=146","title":{"rendered":"Linux\u7cfb\u7edf\u8d1f\u8f7d\u68c0\u67e5\u65b9\u6cd5"},"content":{"rendered":"<h4>1\uff1aload Average<\/h4>\n<h4><span style=\"font-size: 0.83em;\">1.1\uff1a\u4ec0\u4e48\u662fLoad\uff1f\u4ec0\u4e48\u662fLoad Average?<\/span><\/h4>\n<p>Load \u5c31\u662f\u5bf9\u8ba1\u7b97\u673a\u5e72\u6d3b\u591a\u5c11\u7684\u5ea6\u91cf\uff08WikiPedia\uff1athe system Load is a measure of the amount of work that a compute system is doing\uff09\u7b80\u5355\u7684\u8bf4\u662f\u8fdb\u7a0b\u961f\u5217\u7684\u957f\u5ea6\u3002Load Average \u5c31\u662f\u4e00\u6bb5\u65f6\u95f4\uff081\u5206\u949f\u30015\u5206\u949f\u300115\u5206\u949f\uff09\u5185\u5e73\u5747Load\u3002\u3010\u53c2\u8003\u6587\u7ae0\uff1aunix Load Average Part1\uff1aHow It Works\u3011<\/p>\n<p><span style=\"font-size: 0.83em;\">1.2\uff1a\u67e5\u770b\u6307\u4ee4\uff1a<\/span><\/p>\n<p>w or uptime or procinfo or top<\/p>\n<p>load average: 0.02, 0.27, 0.17<br \/>\n1 per\/minute 5 per\/minute 15 per\/minute<\/p>\n<p><span style=\"font-size: 0.83em;\">1.3\uff1a\u5982\u4f55\u5224\u65ad\u7cfb\u7edf\u662f\u5426\u5df2\u7ecfOver Load\uff1f<\/span><\/p>\n<p>\u5bf9\u4e00\u822c\u7684\u7cfb\u7edf\u6765\u8bf4\uff0c\u6839\u636ecpu\u6570\u91cf\u53bb\u5224\u65ad\u3002\u5982\u679c\u5e73\u5747\u8d1f\u8f7d\u59cb\u7ec8\u57281.2\u4e00\u4e0b\uff0c\u800c\u4f60\u67092\u9897cup\u7684\u673a\u5668\u3002\u90a3\u4e48\u57fa\u672c\u4e0d\u4f1a\u51fa\u73b0cpu\u4e0d\u591f\u7528\u7684\u60c5\u51b5\u3002\u4e5f\u5c31\u662fLoad\u5e73\u5747\u8981\u5c0f\u4e8eCpu\u7684\u6570\u91cf<\/p>\n<p><span style=\"font-size: 0.83em;\">1.4\uff1aLoad\u4e0e\u5bb9\u91cf\u89c4\u5212\uff08Capacity Planning\uff09<\/span><\/p>\n<p>\u4e00\u822c\u662f\u4f1a\u6839\u636e15\u5206\u949f\u90a3\u4e2aload \u5e73\u5747\u503c\u4e3a\u9996\u5148\u3002<\/p>\n<p><span style=\"font-size: 0.83em;\">1.5\uff1aLoad\u8bef\u89e3\uff1a<\/span><\/p>\n<p><strong>1\uff1a\u7cfb\u7edfload\u9ad8\u4e00\u5b9a\u662f\u6027\u80fd\u6709\u95ee\u9898\u3002<\/strong><br \/>\n\u771f\u76f8\uff1aLoad\u9ad8\u4e5f\u8bb8\u662f\u56e0\u4e3a\u5728\u8fdb\u884ccpu\u5bc6\u96c6\u578b\u7684\u8ba1\u7b97<br \/>\n<strong>2\uff1a\u7cfb\u7edfLoad\u9ad8\u4e00\u5b9a\u662fCPU\u80fd\u529b\u95ee\u9898\u6216\u6570\u91cf\u4e0d\u591f\u3002<\/strong><br \/>\n\u771f\u76f8\uff1aLoad\u9ad8\u53ea\u662f\u4ee3\u8868\u9700\u8981\u8fd0\u884c\u7684\u961f\u5217\u7d2f\u8ba1\u8fc7\u591a\u4e86\u3002\u4f46\u961f\u5217\u4e2d\u7684\u4efb\u52a1\u5b9e\u9645\u53ef\u80fd\u662f\u8017Cpu\u7684\uff0c\u4e5f\u53ef\u80fd\u662f\u8017i\/0\u5976\u5b50\u5176\u4ed6\u56e0\u7d20\u7684\u3002<br \/>\n<strong>3\uff1a\u7cfb\u7edf\u957f\u671fLoad\u9ad8\uff0c\u9996\u5148\u589e\u52a0CPU<\/strong><br \/>\n\u771f\u76f8\uff1aLoad\u53ea\u662f\u8868\u8c61\uff0c\u4e0d\u662f\u5b9e\u8d28\u3002\u589e\u52a0CPU\u4e2a\u522b\u60c5\u51b5\u4e0b\u4f1a\u4e34\u65f6\u770b\u5230Load\u4e0b\u964d\uff0c\u4f46\u6cbb\u6807\u4e0d\u6cbb\u672c\u3002<\/p>\n<p><span style=\"font-size: 1em;\">2\uff1a\u5728Load average \u9ad8\u7684\u60c5\u51b5\u4e0b\u5982\u4f55\u9274\u522b\u7cfb\u7edf\u74f6\u9888\u3002<\/span><\/p>\n<p>\u662fCPU\u4e0d\u8db3\uff0c\u8fd8\u662fio\u4e0d\u591f\u5feb\u9020\u6210\u6216\u662f\u5185\u5b58\u4e0d\u8db3\uff1f<\/p>\n<p><span style=\"font-size: 0.83em;\">2.1\uff1a\u67e5\u770b\u7cfb\u7edf\u8d1f\u8f7dvmstat<\/span><\/p>\n<p>vmstat<\/p>\n<div>\n<div>\n<pre>procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----\r\nr b   swpd    free  buff  cache   si  so      bi    bo    in  cs   us sy id wa\r\n0 0   100152  2436  97200 289740  0   1       34    45    99  33   0  0  99 0<\/pre>\n<\/div>\n<\/div>\n<p><strong>procs<\/strong><br \/>\nr \u5217\u8868\u793a\u8fd0\u884c\u548c\u7b49\u5f85cpu\u65f6\u95f4\u7247\u7684\u8fdb\u7a0b\u6570\uff0c\u5982\u679c\u957f\u671f\u5927\u4e8e1\uff0c\u8bf4\u660ecpu\u4e0d\u8db3\uff0c\u9700\u8981\u589e\u52a0cpu\u3002<br \/>\nb \u5217\u8868\u793a\u5728\u7b49\u5f85\u8d44\u6e90\u7684\u8fdb\u7a0b\u6570\uff0c\u6bd4\u5982\u6b63\u5728\u7b49\u5f85I\/O\u3001\u6216\u8005\u5185\u5b58\u4ea4\u6362\u7b49\u3002<\/p>\n<p><strong>cpu \u8868\u793acpu\u7684\u4f7f\u7528\u72b6\u6001<\/strong><br \/>\nus \u5217\u663e\u793a\u4e86\u7528\u6237\u65b9\u5f0f\u4e0b\u6240\u82b1\u8d39 CPU \u65f6\u95f4\u7684\u767e\u5206\u6bd4\u3002us\u7684\u503c\u6bd4\u8f83\u9ad8\u65f6\uff0c\u8bf4\u660e\u7528\u6237\u8fdb\u7a0b\u6d88\u8017\u7684cpu\u65f6\u95f4\u591a\uff0c\u4f46\u662f\u5982\u679c\u957f\u671f\u5927\u4e8e50%\uff0c\u9700\u8981\u8003\u8651\u4f18\u5316\u7528\u6237\u7684\u7a0b\u5e8f\u3002<br \/>\nsy \u5217\u663e\u793a\u4e86\u5185\u6838\u8fdb\u7a0b\u6240\u82b1\u8d39\u7684cpu\u65f6\u95f4\u7684\u767e\u5206\u6bd4\u3002\u8fd9\u91ccus + sy\u7684\u53c2\u8003\u503c\u4e3a80%\uff0c\u5982\u679cus+sy \u5927\u4e8e 80%\u8bf4\u660e\u53ef\u80fd\u5b58\u5728CPU\u4e0d\u8db3\u3002<br \/>\nwa \u5217\u663e\u793a\u4e86IO\u7b49\u5f85\u6240\u5360\u7528\u7684CPU\u65f6\u95f4\u7684\u767e\u5206\u6bd4\u3002\u8fd9\u91ccwa\u7684\u53c2\u8003\u503c\u4e3a30%\uff0c\u5982\u679cwa\u8d85\u8fc730%\uff0c\u8bf4\u660eIO\u7b49\u5f85\u4e25\u91cd\uff0c\u8fd9\u53ef\u80fd\u662f\u78c1\u76d8\u5927\u91cf\u968f\u673a\u8bbf\u95ee\u9020\u6210\u7684\uff0c\u4e5f\u53ef\u80fd\u78c1\u76d8\u6216\u8005\u78c1\u76d8\u8bbf\u95ee\u63a7\u5236\u5668\u7684\u5e26\u5bbd\u74f6\u9888\u9020\u6210\u7684(\u4e3b\u8981\u662f\u5757\u64cd\u4f5c)\u3002<br \/>\nid \u5217\u663e\u793a\u4e86cpu\u5904\u5728\u7a7a\u95f2\u72b6\u6001\u7684\u65f6\u95f4\u767e\u5206\u6bd4<\/p>\n<p><strong>system \u663e\u793a\u91c7\u96c6\u95f4\u9694\u5185\u53d1\u751f\u7684\u4e2d\u65ad\u6570<\/strong><br \/>\nin \u5217\u8868\u793a\u5728\u67d0\u4e00\u65f6\u95f4\u95f4\u9694\u4e2d\u89c2\u6d4b\u5230\u7684\u6bcf\u79d2\u8bbe\u5907\u4e2d\u65ad\u6570\u3002<br \/>\ncs\u5217\u8868\u793a\u6bcf\u79d2\u4ea7\u751f\u7684\u4e0a\u4e0b\u6587\u5207\u6362\u6b21\u6570\uff0c\u5982\u5f53 cs \u6bd4\u78c1\u76d8 I\/O \u548c\u7f51\u7edc\u4fe1\u606f\u5305\u901f\u7387\u9ad8\u5f97\u591a\uff0c\u90fd\u5e94\u8fdb\u884c\u8fdb\u4e00\u6b65\u8c03\u67e5\u3002<\/p>\n<p><strong>memory<\/strong><br \/>\nswpd \u5207\u6362\u5230\u5185\u5b58\u4ea4\u6362\u533a\u7684\u5185\u5b58\u6570\u91cf(k\u8868\u793a)\u3002\u5982\u679cswpd\u7684\u503c\u4e0d\u4e3a0\uff0c\u6216\u8005\u6bd4\u8f83\u5927\uff0c\u6bd4\u5982\u8d85\u8fc7\u4e86100m\uff0c\u53ea\u8981si\u3001so\u7684\u503c\u957f\u671f\u4e3a0\uff0c\u7cfb\u7edf\u6027\u80fd\u8fd8\u662f\u6b63\u5e38<br \/>\nfree \u5f53\u524d\u7684\u7a7a\u95f2\u9875\u9762\u5217\u8868\u4e2d\u5185\u5b58\u6570\u91cf(k\u8868\u793a)<br \/>\nbuff \u4f5c\u4e3abuffer cache\u7684\u5185\u5b58\u6570\u91cf\uff0c\u4e00\u822c\u5bf9\u5757\u8bbe\u5907\u7684\u8bfb\u5199\u624d\u9700\u8981\u7f13\u51b2\u3002<br \/>\ncache: \u4f5c\u4e3apage cache\u7684\u5185\u5b58\u6570\u91cf\uff0c\u4e00\u822c\u4f5c\u4e3a\u6587\u4ef6\u7cfb\u7edf\u7684cache\uff0c\u5982\u679ccache\u8f83\u5927\uff0c\u8bf4\u660e\u7528\u5230cache\u7684\u6587\u4ef6\u8f83\u591a\uff0c\u5982\u679c\u6b64\u65f6IO\u4e2dbi\u6bd4\u8f83\u5c0f\uff0c\u8bf4\u660e\u6587\u4ef6\u7cfb\u7edf\u6548\u7387\u6bd4\u8f83\u597d\u3002<\/p>\n<p><strong>swap<\/strong><br \/>\nsi \u7531\u5185\u5b58\u8fdb\u5165\u5185\u5b58\u4ea4\u6362\u533a\u6570\u91cf\u3002<br \/>\nso\u7531\u5185\u5b58\u4ea4\u6362\u533a\u8fdb\u5165\u5185\u5b58\u6570\u91cf\u3002<\/p>\n<p><strong>io<\/strong><br \/>\nbi \u4ece\u5757\u8bbe\u5907\u8bfb\u5165\u6570\u636e\u7684\u603b\u91cf\uff08\u8bfb\u78c1\u76d8\uff09\uff08\u6bcf\u79d2kb\uff09\u3002<br \/>\nbo \u5757\u8bbe\u5907\u5199\u5165\u6570\u636e\u7684\u603b\u91cf\uff08\u5199\u78c1\u76d8\uff09\uff08\u6bcf\u79d2kb\uff09<br \/>\n\u8fd9\u91cc\u6211\u4eec\u8bbe\u7f6e\u7684bi+bo\u53c2\u8003\u503c\u4e3a1000\uff0c\u5982\u679c\u8d85\u8fc71000\uff0c\u800c\u4e14wa\u503c\u8f83\u5927\u5e94\u8be5\u8003\u8651\u5747\u8861\u78c1\u76d8\u8d1f\u8f7d\uff0c\u53ef\u4ee5\u7ed3\u5408iostat\u8f93\u51fa\u6765\u5206\u6790\u3002<\/p>\n<p><span style=\"font-size: 0.83em;\">2.2\uff1a\u67e5\u770b\u78c1\u76d8\u8d1f\u8f7diostat<\/span><\/p>\n<p>\u6bcf\u96942\u79d2\u7edf\u8ba1\u4e00\u6b21\u78c1\u76d8IO\u4fe1\u606f\uff0c\u76f4\u5230\u6309Ctrl+C\u7ec8\u6b62\u7a0b\u5e8f\uff0c<br \/>\n-d \u9009\u9879\u8868\u793a\u7edf\u8ba1\u78c1\u76d8\u4fe1\u606f\uff0c<br \/>\n-k \u8868\u793a\u4ee5\u6bcf\u79d2KB\u7684\u5f62\u5f0f\u663e\u793a\uff0c<br \/>\n-t \u8981\u6c42\u6253\u5370\u51fa\u65f6\u95f4\u4fe1\u606f\uff0c<br \/>\n2 \u8868\u793a\u6bcf\u9694 2 \u79d2\u8f93\u51fa\u4e00\u6b21\u3002<br \/>\n\u7b2c\u4e00\u6b21\u8f93\u51fa\u7684\u78c1\u76d8IO\u8d1f\u8f7d\u72b6\u51b5\u63d0\u4f9b\u4e86\u5173\u4e8e\u81ea\u4ece\u7cfb\u7edf\u542f\u52a8\u4ee5\u6765\u7684\u7edf\u8ba1\u4fe1\u606f\u3002\u968f\u540e\u7684\u6bcf\u4e00\u6b21\u8f93\u51fa\u5219\u662f\u6bcf\u4e2a\u95f4\u9694\u4e4b\u95f4\u7684\u5e73\u5747IO\u8d1f\u8f7d\u72b6\u51b5\u3002<br \/>\n<strong>iostat -x\u00a01 10<\/strong><\/p>\n<div>\n<div>\n<pre>Linux 2.6.18-92.el5xen 02\/03\/2009\r\navg-cpu: %user %nice %system %iowait %steal %idle\r\n         1.10  0.00  4.82    39.54   0.07   54.46\r\n\r\nDevice: rrqm\/s wrqm\/s r\/s    w\/s   rsec\/s  wsec\/s avgrq-sz avgqu-sz await svctm %util\r\n   sda  0.00   3.50   0.40   2.50  5.60    48.00  18.48    0.00     0.97  0.97  0.28\r\n   sdb  0.00   0.00   0.00   0.00  0.00    0.00   0.00     0.00     0.00  0.00  0.00\r\n   sdc  0.00   0.00   0.00   0.00  0.00    0.00   0.00     0.00     0.00  0.00  0.00\r\n   sdd  0.00   0.00   0.00   0.00  0.00    0.00   0.00     0.00     0.00  0.00  0.00\r\n   sde  0.00   0.10   0.30   0.20  2.40    2.40   9.60     0.00     1.60  1.60  0.08\r\n   sdf  17.40  0.50   102.00 0.20 12095.20 5.60   118.40   0.70     6.81  2.09  21.36\r\n   sdg  232.40 1.90   379.70 0.50 76451.20 19.20  201.13   4.94     13.78 2.45  93.16<\/pre>\n<\/div>\n<\/div>\n<p>rrqm\/s: \u6bcf\u79d2\u8fdb\u884c merge \u7684\u8bfb\u64cd\u4f5c\u6570\u76ee\u3002\u5373 delta(rmerge)\/s<br \/>\nwrqm\/s: \u6bcf\u79d2\u8fdb\u884c merge \u7684\u5199\u64cd\u4f5c\u6570\u76ee\u3002\u5373 delta(wmerge)\/s<br \/>\nr\/s: \u6bcf\u79d2\u5b8c\u6210\u7684\u8bfb I\/O \u8bbe\u5907\u6b21\u6570\u3002\u5373 delta(rio)\/s<br \/>\nw\/s: \u6bcf\u79d2\u5b8c\u6210\u7684\u5199 I\/O \u8bbe\u5907\u6b21\u6570\u3002\u5373 delta(wio)\/s<br \/>\nrsec\/s: \u6bcf\u79d2\u8bfb\u6247\u533a\u6570\u3002\u5373 delta(rsect)\/s<br \/>\nwsec\/s: \u6bcf\u79d2\u5199\u6247\u533a\u6570\u3002\u5373 delta(wsect)\/s<br \/>\nrkB\/s: \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)<br \/>\nwkB\/s: \u6bcf\u79d2\u5199K\u5b57\u8282\u6570\u3002\u662f wsect\/s \u7684\u4e00\u534a\u3002(\u9700\u8981\u8ba1\u7b97)<br \/>\navgrq-sz: \u5e73\u5747\u6bcf\u6b21\u8bbe\u5907I\/O\u64cd\u4f5c\u7684\u6570\u636e\u5927\u5c0f (\u6247\u533a)\u3002delta(rsect+wsect)\/delta(rio+wio)<br \/>\navgqu-sz: \u5e73\u5747I\/O\u961f\u5217\u957f\u5ea6\u3002\u5373 delta(aveq)\/s\/1000 (\u56e0\u4e3aaveq\u7684\u5355\u4f4d\u4e3a\u6beb\u79d2)\u3002<br \/>\nawait: \u5e73\u5747\u6bcf\u6b21\u8bbe\u5907I\/O\u64cd\u4f5c\u7684\u7b49\u5f85\u65f6\u95f4 (\u6beb\u79d2)\u3002\u5373 delta(ruse+wuse)\/delta(rio+wio)<br \/>\nsvctm: \u5e73\u5747\u6bcf\u6b21\u8bbe\u5907I\/O\u64cd\u4f5c\u7684\u670d\u52a1\u65f6\u95f4 (\u6beb\u79d2)\u3002\u5373 delta(use)\/delta(rio+wio)<br \/>\n%util: \u4e00\u79d2\u4e2d\u6709\u767e\u5206\u4e4b\u591a\u5c11\u7684\u65f6\u95f4\u7528\u4e8e I\/O \u64cd\u4f5c\uff0c\u6216\u8005\u8bf4\u4e00\u79d2\u4e2d\u6709\u591a\u5c11\u65f6\u95f4 I\/O \u961f\u5217\u662f\u975e\u7a7a\u7684\u3002\u5373 delta(use)\/s\/1000 (\u56e0\u4e3ause\u7684\u5355\u4f4d\u4e3a\u6beb\u79d2)<\/p>\n<p>\u5982\u679c %util \u63a5\u8fd1 100%\uff0c\u8bf4\u660e\u4ea7\u751f\u7684I\/O\u8bf7\u6c42\u592a\u591a\uff0cI\/O\u7cfb\u7edf\u5df2\u7ecf\u6ee1\u8d1f\u8377\uff0c\u8be5\u78c1\u76d8\u53ef\u80fd\u5b58\u5728\u74f6\u9888\u3002<\/p>\n<p>idle\u5c0f\u4e8e70% IO\u538b\u529b\u5c31\u8f83\u5927\u4e86,\u4e00\u822c\u8bfb\u53d6\u901f\u5ea6\u6709\u8f83\u591a\u7684wait.<\/p>\n<p>\u540c\u65f6\u53ef\u4ee5\u7ed3\u5408vmstat \u67e5\u770b\u67e5\u770bb\u53c2\u6570(\u7b49\u5f85\u8d44\u6e90\u7684\u8fdb\u7a0b\u6570)\u548cwa\u53c2\u6570(IO\u7b49\u5f85\u6240\u5360\u7528\u7684CPU\u65f6\u95f4\u7684\u767e\u5206\u6bd4,\u9ad8\u8fc730%\u65f6IO\u538b\u529b\u9ad8)<\/p>\n<p><strong>\u53e6\u5916\u8fd8\u53ef\u4ee5\u53c2\u8003<\/strong><br \/>\n\u4e00\u822c:<br \/>\nsvctm &lt; await (\u56e0\u4e3a\u540c\u65f6\u7b49\u5f85\u7684\u8bf7\u6c42\u7684\u7b49\u5f85\u65f6\u95f4\u88ab\u91cd\u590d\u8ba1\u7b97\u4e86)\uff0c<br \/>\nsvctm\u7684\u5927\u5c0f\u4e00\u822c\u548c\u78c1\u76d8\u6027\u80fd\u6709\u5173:CPU\/\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\u3002<br \/>\nawait: await\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<br \/>\n\u5982\u679c svctm \u6bd4\u8f83\u63a5\u8fd1 await\uff0c\u8bf4\u660eI\/O \u51e0\u4e4e\u6ca1\u6709\u7b49\u5f85\u65f6\u95f4\uff1b<br \/>\n\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<br \/>\n\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<br \/>\n\u961f\u5217\u957f\u5ea6(avgqu-sz)\u4e5f\u53ef\u4f5c\u4e3a\u8861\u91cf\u7cfb\u7edf I\/O \u8d1f\u8377\u7684\u6307\u6807\uff0c\u4f46\u7531\u4e8e avgqu-sz \u662f\u6309\u7167\u5355\u4f4d\u65f6\u95f4\u7684\u5e73\u5747\u503c\uff0c\u6240\u4ee5\u4e0d\u80fd\u53cd\u6620\u77ac\u95f4\u7684 I\/O \u6d2a\u6c34\u3002<\/p>\n<p><strong>\u522b\u4eba\u4e00\u4e2a\u4e0d\u9519\u7684\u4f8b\u5b50.(I\/O \u7cfb\u7edf vs. \u8d85\u5e02\u6392\u961f)<\/strong><br \/>\n\u4e3e\u4e00\u4e2a\u4f8b\u5b50\uff0c\u6211\u4eec\u5728\u8d85\u5e02\u6392\u961fcheckout\u65f6\uff0c\u600e\u4e48\u51b3\u5b9a\u8be5\u53bb\u54ea\u4e2a\u4ea4\u6b3e\u53f0\u5462? \u9996\u5f53\u662f\u770b\u6392\u7684\u961f\u4eba\u6570\uff0c5\u4e2a\u4eba\u603b\u6bd420\u4eba\u8981\u5feb\u5427\uff1f\u9664\u4e86\u6570\u4eba\u5934\uff0c\u6211\u4eec\u4e5f\u5e38\u5e38\u770b\u770b\u524d\u9762\u4eba\u8d2d\u4e70\u7684\u4e1c\u897f\u591a\u5c11\uff0c\u5982\u679c\u524d\u9762\u6709\u4e2a\u91c7\u8d2d\u4e86\u4e00\u661f\u671f\u98df\u54c1\u7684\u5927\u5988\uff0c\u90a3\u4e48\u53ef\u4ee5\u8003\u8651\u6362\u4e2a \u961f\u6392\u4e86\u3002\u8fd8\u6709\u5c31\u662f\u6536\u94f6\u5458\u7684\u901f\u5ea6\u4e86\uff0c\u5982\u679c\u78b0\u4e0a\u4e86\u8fde\u94b1\u90fd\u70b9\u4e0d\u6e05\u695a\u7684\u65b0\u624b\uff0c\u90a3\u5c31\u6709\u7684\u7b49\u4e86\u3002\u53e6\u5916\uff0c\u65f6\u673a\u4e5f\u5f88\u91cd\u8981\uff0c\u53ef\u80fd 5\u5206\u949f\u524d\u8fd8\u4eba\u6ee1\u4e3a\u60a3\u7684\u6536\u6b3e\u53f0\uff0c\u73b0\u5728\u5df2\u662f\u4eba\u53bb\u697c\u7a7a\uff0c\u8fd9\u65f6\u5019\u4ea4\u6b3e\u53ef\u662f\u5f88\u723d\u554a\uff0c\u5f53\u7136\uff0c\u524d\u63d0\u662f\u90a3\u8fc7\u53bb\u7684 5 \u5206\u949f\u91cc\u6240\u505a\u7684\u4e8b\u60c5\u6bd4\u6392\u961f\u8981\u6709\u610f\u4e49(\u4e0d\u8fc7\u6211\u8fd8\u6ca1\u53d1\u73b0\u4ec0\u4e48\u4e8b\u60c5\u6bd4\u6392\u961f\u8fd8\u65e0\u804a\u7684)\u3002<\/p>\n<p>I\/O \u7cfb\u7edf\u4e5f\u548c\u8d85\u5e02\u6392\u961f\u6709\u5f88\u591a\u7c7b\u4f3c\u4e4b\u5904:<br \/>\nr\/s+w\/s \u7c7b\u4f3c\u4e8e\u4ea4\u6b3e\u4eba\u7684\u603b\u6570<br \/>\n\u5e73\u5747\u961f\u5217\u957f\u5ea6(avgqu-sz)\u7c7b\u4f3c\u4e8e\u5355\u4f4d\u65f6\u95f4\u91cc\u5e73\u5747\u6392\u961f\u4eba\u7684\u4e2a\u6570<br \/>\n\u5e73\u5747\u670d\u52a1\u65f6\u95f4(svctm)\u7c7b\u4f3c\u4e8e\u6536\u94f6\u5458\u7684\u6536\u6b3e\u901f\u5ea6<br \/>\n\u5e73\u5747\u7b49\u5f85\u65f6\u95f4(await)\u7c7b\u4f3c\u4e8e\u5e73\u5747\u6bcf\u4eba\u7684\u7b49\u5f85\u65f6\u95f4<br \/>\n\u5e73\u5747I\/O\u6570\u636e(avgrq-sz)\u7c7b\u4f3c\u4e8e\u5e73\u5747\u6bcf\u4eba\u6240\u4e70\u7684\u4e1c\u897f\u591a\u5c11<br \/>\nI\/O \u64cd\u4f5c\u7387 (%util)\u7c7b\u4f3c\u4e8e\u6536\u6b3e\u53f0\u524d\u6709\u4eba\u6392\u961f\u7684\u65f6\u95f4\u6bd4\u4f8b\u3002<br \/>\n\u6211\u4eec\u53ef\u4ee5\u6839\u636e\u8fd9\u4e9b\u6570\u636e\u5206\u6790\u51fa I\/O \u8bf7\u6c42\u7684\u6a21\u5f0f\uff0c\u4ee5\u53ca I\/O \u7684\u901f\u5ea6\u548c\u54cd\u5e94\u65f6\u95f4\u3002<br \/>\n\u4e0b\u9762\u662f\u522b\u4eba\u5199\u7684\u8fd9\u4e2a\u53c2\u6570\u8f93\u51fa\u7684\u5206\u6790<br \/>\n<strong>iostat -x 1<\/strong><\/p>\n<div>\n<div>\n<pre>  avg-cpu: %user %nice %sys %idle\r\n           16.24 0.00  4.31 79.44\r\n\r\n  Device: rrqm\/s wrqm\/s r\/s  w\/s   rsec\/s wsec\/s rkB\/s wkB\/s  avgrq-sz avgqu-sz await svctm %util\r\n  sda     0.00   44.90  1.02 27.55 8.16   579.59 4.08  289.80 20.57    22.35    78.21 5.00  14.29\r\n  sdb     0.00   44.90  1.02 27.55 8.16   579.59 4.08  289.80 20.57    22.35    78.21 5.00  14.29\r\n  sdc     0.00   0.00   0.00 0.00  0.00   0.00   0.00  0.00   0.00     0.00     0.00  0.00  0.00<\/pre>\n<\/div>\n<\/div>\n<p>\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<br \/>\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:<br \/>\n\u5e73\u5747\u7b49\u5f85\u65f6\u95f4 = \u5355\u4e2a I\/O \u670d\u52a1\u65f6\u95f4 * ( 1 + 2 + &#8230; + \u8bf7\u6c42\u603b\u6570-1) \/ \u8bf7\u6c42\u603b\u6570<br \/>\n\u5e94\u7528\u5230\u4e0a\u9762\u7684\u4f8b\u5b50: \u5e73\u5747\u7b49\u5f85\u65f6\u95f4 = 5ms * (1+2+&#8230;+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<br \/>\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<br \/>\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<br \/>\ndelta(ruse+wuse)\/delta(io) = await = 78.21 =&gt; 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\u800ciostat \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","protected":false},"excerpt":{"rendered":"<p>1\uff1aload Average 1.1\uff1a\u4ec0\u4e48\u662fLoad\uff1f\u4ec0\u4e48\u662fLoad Average? Load \u5c31\u662f\u5bf9\u8ba1\u7b97\u673a\u5e72\u6d3b\u591a\u5c11\u7684\u5ea6\u91cf\uff08WikiPedia\uff1athe system Load is a measure of the amount of work that a compute system is doing\uff09\u7b80\u5355\u7684\u8bf4\u662f<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[11],"tags":[87,88],"_links":{"self":[{"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/posts\/146"}],"collection":[{"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=146"}],"version-history":[{"count":2,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/posts\/146\/revisions"}],"predecessor-version":[{"id":148,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/posts\/146\/revisions\/148"}],"wp:attachment":[{"href":"https:\/\/www.codeeel.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=146"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=146"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}