{"id":6025,"date":"2022-06-17T09:47:16","date_gmt":"2022-06-17T01:47:16","guid":{"rendered":"http:\/\/lrxjmw.cn\/?p=6025"},"modified":"2022-06-17T17:05:39","modified_gmt":"2022-06-17T09:05:39","slug":"understand-iowait","status":"publish","type":"post","link":"https:\/\/lrxjmw.cn\/understand-iowait.html","title":{"rendered":"\u7406\u89e3 %IOWAIT (%WIO)"},"content":{"rendered":"<div   id="j6sjwn9j3u"    class=\"alert alert-info\">\n<p style=\"text-align: center;\">\u672c\u6587\u7531lrxjmw.cn\u56e2\u961f\u6210\u5458<span style=\"text-decoration: underline;\">\u9b4f\u4e3d\u733f<\/span>\u6574\u7406\u53d1\u5e03\uff0c\u539f\u6587\u6765\u81ea\uff1a<a href=\"http:\/\/linuxperf.com\/?cat=11\" target=\"_blank\" rel=\"nofollow noopener\">Linux Performance<\/a>\u3002<\/p>\n<\/div>\n<p><strong>%iowait<\/strong> \u662f \u201c<strong>sar -u<\/strong>\u201d \u7b49\u5de5\u5177\u68c0\u67e5CPU\u4f7f\u7528\u7387\u65f6\u663e\u793a\u7684\u4e00\u4e2a\u6307\u6807\uff0c\u5728Linux\u4e0a\u663e\u793a\u4e3a %iowait\uff0c\u5728\u6709\u7684Unix\u7248\u672c\u4e0a\u663e\u793a\u4e3a %wio\uff0c\u542b\u4e49\u90fd\u662f\u4e00\u6837\u7684,\u8fd9\u4e2a\u6307\u6807\u5e38\u5e38\u88ab\u8bef\u8bfb\uff0c\u5f88\u591a\u4eba\u628a\u5b83\u5f53\u4f5cI\/O\u95ee\u9898\u7684\u5f81\u5146\uff0c\u6211\u81ea\u5df1\u6bcf\u9694\u4e00\u6bb5\u65f6\u95f4\u5c31\u4f1a\u9047\u5230\u5bf9 %iowait \u7d27\u5f20\u516e\u516e\u7684\u5ba2\u6237\uff0c\u4e0d\u5f97\u4e0d\u8d39\u5c3d\u5507\u820c\u53cd\u590d\u89e3\u91ca\uff0c\u4e8b\u5b9e\u4e0a\u8fd9\u4e2a\u6307\u6807\u6240\u542b\u7684\u4fe1\u606f\u91cf\u975e\u5e38\u5c11\uff0c\u4e0d\u80fd\u5355\u72ec\u7528\u6765\u5224\u65ad\u7cfb\u7edf\u6709\u6ca1\u6709I\/O\u95ee\u9898\uff0c\u5728\u6b64\u6211\u4eec\u8be6\u7ec6\u63a2\u8ba8\u4e00\u4e0b\u5b83\u771f\u6b63\u7684\u542b\u4e49\uff0c\u5148\u4eceman page\u4e0a\u7684\u89e3\u91ca\u5f00\u59cb\uff1a<\/p>\n<pre>09:35:06 AM     CPU     %user     %nice   %system   %iowait    %steal     %idle\r\n09:35:07 AM     all      0.00      0.00      0.00      0.00      0.00    100.00\r\n09:35:08 AM     all      0.51      0.00      2.53     13.13      0.00     83.84\r\n09:35:09 AM     all      1.54      0.00      7.69     39.49      0.00     51.28\r\n09:35:10 AM     all      2.04      0.00      9.18     39.80      0.00     48.98\r\n09:35:11 AM     all      1.02      0.00      7.65     40.31      0.00     51.02<\/pre>\n<p>\u4e0b\u9762\u662fman page\u4e2d\u7684\u90e8\u5206\u89e3\u91ca\uff1a<\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li><strong><\/strong><strong>Linux:<\/strong><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<pre>%iowait\r\nPercentage of time that the CPU or CPUs were idle during\r\nwhich the system had an outstanding disk I\/O request.<\/pre>\n<p>&nbsp;<\/p>\n<ol>\n<\/ol>\n<ol>\n<li>HP-UX:<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<pre>%wio\r\nidle with some process waiting for I\/O (only block I\/O, raw\r\nI\/O, or VM pageins\/swapins indicated).<\/pre>\n<p>Linux\u548cHP-UX\u7684<strong>man page<\/strong>\u5206\u522b\u4ece\u4e24\u4e2a\u89d2\u5ea6\u63cf\u8ff0\u4e86\u8fd9\u4e2a\u6307\u6807\uff1aLinux\u7740\u773c\u4e8eI\/O\uff0c\u5f3a\u8c03\u7684\u662f\u4ecd\u6709\u672a\u5b8c\u6210\u7684I\/O\u8bf7\u6c42\uff1b\u800cHP-UX\u7740\u773c\u4e8e\u8fdb\u7a0b\uff0c\u5f3a\u8c03\u7684\u662f\u4ecd\u6709\u8fdb\u7a0b\u5728\u7b49\u5f85I\/O,\u4e8c\u8005\u6240\u8bf4\u7684\u662f\u540c\u4e00\u4ef6\u4e8b\u7684\u4e24\u4e2a\u65b9\u9762\uff0c\u5982\u679c\u5408\u5728\u4e00\u8d77\u5c31\u5b8c\u6574\u4e86\uff0c\u5c31\u662f\uff1a<strong>\u81f3\u5c11\u6709\u4e00\u4e2aI\/O\u8bf7\u6c42\u5c1a\u672a\u5b8c\u6210\uff0c\u6709\u8fdb\u7a0b\u56e0\u4e3a\u7b49\u5f85\u5b83\u800c\u4f11\u7720<\/strong>,\u6211\u4eec\u4e0d\u59a8\u91c7\u7eb3Linux\u7684\u63aa\u8f9e\uff0c%iowait \u8868\u793a\u5728\u4e00\u4e2a\u91c7\u6837\u5468\u671f\u5185\u6709\u767e\u5206\u4e4b\u51e0\u7684\u65f6\u95f4\u5c5e\u4e8e\u4ee5\u4e0b\u60c5\u51b5\uff1aCPU\u7a7a\u95f2\u3001\u5e76\u4e14\u6709\u4ecd\u672a\u5b8c\u6210\u7684I\/O\u8bf7\u6c42\u3002<br \/>\n<strong>\u5bf9 %iowait \u5e38\u89c1\u7684\u8bef\u89e3\u6709\u4e24\u4e2a\uff1a<\/strong><\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li><strong><\/strong><strong>\u662f\u8bef\u4ee5\u4e3a %iowait \u8868\u793aCPU\u4e0d\u80fd\u5de5\u4f5c\u7684\u65f6\u95f4<\/strong><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<ol>\n<\/ol>\n<ol>\u8fd9\u79cd\u8bef\u89e3\u592a\u4f4e\u7ea7\u4e86\uff0c%iowait \u7684\u9996\u8981\u6761\u4ef6\u5c31\u662fCPU\u7a7a\u95f2\uff0c\u65e2\u7136\u7a7a\u95f2\u5f53\u7136\u5c31\u53ef\u4ee5\u63a5\u53d7\u8fd0\u884c\u4efb\u52a1\uff0c\u53ea\u662f\u56e0\u4e3a\u6ca1\u6709\u8fdb\u7a0b\u53ef\u4ee5\u8fd0\u884c\uff0cCPU\u624d\u8fdb\u5165\u7a7a\u95f2\u72b6\u6001\u7684\u3002\u90a3\u4e3a\u4ec0\u4e48\u6ca1\u6709\u8fdb\u7a0b\u53ef\u4ee5\u8fd0\u884c\u5462\uff1f\u56e0\u4e3a\u8fdb\u7a0b\u90fd\u5904\u4e8e\u4f11\u7720\u72b6\u6001\u3001\u5728\u7b49\u5f85\u67d0\u4e2a\u7279\u5b9a\u4e8b\u4ef6\uff1a\u6bd4\u5982\u7b49\u5f85\u5b9a\u65f6\u5668\u3001\u6216\u8005\u6765\u81ea\u7f51\u7edc\u7684\u6570\u636e\u3001\u6216\u8005\u952e\u76d8\u8f93\u5165\u3001\u6216\u8005\u7b49\u5f85I\/O\u64cd\u4f5c\u5b8c\u6210\uff0c\u7b49\u7b49\u3002<\/ol>\n<p>&nbsp;<\/p>\n<ul>\n<li><strong><\/strong><strong>\u662f\u8bef\u4ee5\u4e3a %iowait \u8868\u793aI\/O\u6709\u74f6\u9888\u95ee\u9898<\/strong><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<ol>\u4e3a\u4ec0\u4e48\u4eba\u4eec\u4f1a\u8ba4\u4e3a %iowait \u504f\u9ad8\u662f\u6709I\/O\u95ee\u9898\u7684\u8ff9\u8c61\u5462\uff1f\u4ed6\u4eec\u7684\u7406\u7531\u662f\uff1a\u201d%iowait \u7684\u7b2c\u4e00\u4e2a\u6761\u4ef6\u662fCPU\u7a7a\u95f2\uff0c\u610f\u5373\u6240\u6709\u7684\u8fdb\u7a0b\u90fd\u5728\u4f11\u7720\uff0c\u7b2c\u4e8c\u4e2a\u6761\u4ef6\u662f\u4ecd\u6709\u672a\u5b8c\u6210\u7684I\/O\u8bf7\u6c42\uff0c\u610f\u5473\u7740\u8fdb\u7a0b\u4f11\u7720\u7684\u539f\u56e0\u662f\u7b49\u5f85I\/O\uff0c\u800c %iowait \u5347\u9ad8\u5219\u8868\u660e\u56e0\u7b49\u5f85I\/O\u800c\u4f11\u7720\u7684\u8fdb\u7a0b\u6570\u91cf\u66f4\u591a\u4e86\u3001\u6216\u8005\u8fdb\u7a0b\u56e0\u7b49\u5f85I\/O\u800c\u4f11\u7720\u7684\u65f6\u95f4\u66f4\u957f\u4e86\u3002\u201c \u542c\u4e0a\u53bb\u4f3c\u4e4e\u5f88\u6709\u9053\u7406\uff0c\u4f46\u662f\u4e0d\u5bf9\uff1a\u9996\u5148 %iowait \u786e\u5b9e\u8868\u793aCPU\u7a7a\u95f2\u3001\u6240\u6709\u8fdb\u7a0b\u90fd\u5728\u4f11\u7720\uff0c\u4e5f\u786e\u5b9e\u6709\u7684\u8fdb\u7a0b\u5728\u7b49\u5f85I\/O\uff0c\u7136\u800c %iowait \u5347\u9ad8\u5e76\u4e0d\u80fd\u8bc1\u660e\u7b49\u5f85I\/O\u7684\u8fdb\u7a0b\u6570\u91cf\u589e\u591a\u4e86\uff0c\u4e5f\u4e0d\u80fd\u8bc1\u660e\u7b49\u5f85I\/O\u7684\u603b\u65f6\u95f4\u589e\u52a0\u4e86\u3002<\/ol>\n<p>\u4e3a\u4ec0\u4e48\u5462\uff1f\u770b\u770b\u4e0b\u9762\u4e24\u5f20\u56fe\u5c31\u660e\u767d\u4e86:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6027\" src=\"http:\/\/lrxjmw.cn\/wp-content\/uploads\/2016\/01\/iowait1.png\" alt=\"iowait1\" width=\"634\" height=\"225\" srcset=\"https:\/\/lrxjmw.cn\/wp-content\/uploads\/2016\/01\/iowait1.png 634w, https:\/\/lrxjmw.cn\/wp-content\/uploads\/2016\/01\/iowait1-300x106.png 300w\" sizes=\"auto, (max-width: 634px) 100vw, 634px\" \/><br \/>\n\u7b2c\u4e00\u5f20\u56fe\u6f14\u793a\u7684\u662f:\u5728I\/O\u5b8c\u5168\u4e00\u6837\u7684\u60c5\u51b5\u4e0b\uff0cCPU\u5fd9\u95f2\u72b6\u6001\u7684\u53d8\u5316\u5c31\u80fd\u591f\u5f71\u54cd %iowait \u7684\u5927\u5c0f\uff0c\u56fe\u4e2d\u6211\u4eec\u770b\u5230\uff0c\u5728CPU\u7e41\u5fd9\u671f\u95f4\u53d1\u751f\u7684I\/O\uff0c\u65e0\u8bba\u6709\u591a\u5c11\uff0c%iowait \u7684\u503c\u90fd\u662f\u4e0d\u53d7\u5f71\u54cd\u7684\uff08\u56e0\u4e3a %iowait \u7684\u7b2c\u4e00\u4e2a\u524d\u63d0\u6761\u4ef6\u5c31\u662fCPU\u5fc5\u987b\u7a7a\u95f2\uff09\uff1b\u5f53CPU\u7e41\u5fd9\u7a0b\u5ea6\u4e0b\u964d\u65f6\uff0c\u6709\u4e00\u90e8\u5206I\/O\u843d\u5165\u4e86CPU\u7a7a\u95f2\u7684\u65f6\u95f4\u6bb5\u5185\uff0c\u8fd9\u5c31\u5bfc\u81f4\u4e86 %iowait \u5347\u9ad8\uff0c\u53ef\u89c1\uff0cI\/O\u5e76\u6ca1\u6709\u53d8\u5316\uff0c%iowait \u5374\u5347\u9ad8\u4e86\uff0c\u539f\u56e0\u4ec5\u4ec5\u662fCPU\u7684\u7a7a\u95f2\u65f6\u95f4\u589e\u52a0\u4e86\uff0c\u8bf7\u8bb0\u4f4f\uff0c\u7cfb\u7edf\u4e2d\u6709\u6210\u767e\u4e0a\u5343\u7684\u8fdb\u7a0b\u6570\uff0c\u4efb\u4f55\u4e00\u4e2a\u8fdb\u7a0b\u90fd\u53ef\u4ee5\u5f15\u8d77CPU\u548cI\/O\u7684\u53d8\u5316\uff0c\u56e0\u4e3a %iowait\u3001%idle\u3001%user\u3001%system \u7b49\u8fd9\u4e9b\u6307\u6807\u90fd\u662f\u5168\u5c40\u6027\u7684\uff0c\u5e76\u4e0d\u662f\u7279\u6307\u67d0\u4e2a\u8fdb\u7a0b\u3002<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6028\" src=\"http:\/\/lrxjmw.cn\/wp-content\/uploads\/2016\/01\/iowait2.png\" alt=\"iowait2\" width=\"526\" height=\"498\" srcset=\"https:\/\/lrxjmw.cn\/wp-content\/uploads\/2016\/01\/iowait2.png 526w, https:\/\/lrxjmw.cn\/wp-content\/uploads\/2016\/01\/iowait2-300x284.png 300w\" sizes=\"auto, (max-width: 526px) 100vw, 526px\" \/><br \/>\n\u518d\u770b\u7b2c\u4e8c\u5f20\u56fe\uff0c\u5b83\u63cf\u8ff0\u4e86\u53e6\u4e00\u79cd\u60c5\u5f62\uff1a\u5047\u8bbeCPU\u7684\u7e41\u5fd9\u72b6\u51b5\u4fdd\u6301\u4e0d\u53d8\u7684\u6761\u4ef6\u4e0b\uff0c\u5373\u4f7f %iowait \u5347\u9ad8\u4e5f\u4e0d\u80fd\u8bf4\u660eI\/O\u8d1f\u8f7d\u52a0\u91cd\u4e86\uff0c\u5982\u679c2\u4e2aI\/O\u8bf7\u6c42\u4f9d\u6b21\u63d0\u4ea4\u3001\u4f7f\u5f97\u6574\u4e2a\u65f6\u6bb5\u5185\u59cb\u7ec8\u6709I\/O\u5728\u8fdb\u884c\uff0c\u90a3\u4e48 %iowait \u662f100%\uff1b\u5982\u679c3\u4e2aI\/O\u8bf7\u6c42\u540c\u65f6\u63d0\u4ea4\uff0c\u56e0\u4e3a\u7cfb\u7edf\u6709\u80fd\u529b\u540c\u65f6\u5904\u7406\u591a\u4e2aI\/O\uff0c\u6240\u4ee53\u4e2a\u5e76\u53d1\u7684I\/O\u4ece\u5f00\u59cb\u5230\u7ed3\u675f\u7684\u65f6\u95f4\u4e0e\u4e00\u4e2aI\/O\u4e00\u6837\uff0c%iowait \u7684\u7ed3\u679c\u53ea\u670950%\uff1b2\u4e2aI\/O\u4f7f %iowait \u8fbe\u5230\u4e86100%\uff0c3\u4e2aI\/O\u7684 %iowait \u5374\u53ea\u670950%\uff0c\u663e\u7136 %iowait \u7684\u9ad8\u4f4e\u4e0eI\/O\u7684\u591a\u5c11\u6ca1\u6709\u5fc5\u7136\u5173\u7cfb\uff0c\u800c\u662f\u4e0eI\/O\u7684\u5e76\u53d1\u5ea6\u76f8\u5173\uff0c\u6240\u4ee5\uff0c\u4ec5\u51ed %iowait \u7684\u4e0a\u5347\u4e0d\u80fd\u5f97\u51faI\/O\u8d1f\u8f7d\u589e\u52a0 \u7684\u7ed3\u8bba\u3002<\/p>\n<p>\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48\u8bf4 %iowait \u6240\u542b\u7684\u4fe1\u606f\u91cf\u975e\u5e38\u5c11\u7684\u539f\u56e0\uff0c\u5b83\u662f\u4e00\u4e2a\u975e\u5e38\u6a21\u7cca\u7684\u6307\u6807\uff0c\u5982\u679c\u770b\u5230 %iowait \u5347\u9ad8\uff0c\u8fd8\u9700\u68c0\u67e5I\/O\u91cf\u6709\u6ca1\u6709\u660e\u663e\u589e\u52a0\uff0cavserv\/avwait\/avque\u7b49\u6307\u6807\u6709\u6ca1\u6709\u660e\u663e\u589e\u5927\uff0c\u5e94\u7528\u6709\u6ca1\u6709\u611f\u89c9\u53d8\u6162\uff0c\u5982\u679c\u90fd\u6ca1\u6709\uff0c\u5c31\u6ca1\u4ec0\u4e48\u597d\u62c5\u5fc3\u7684\u3002<\/p>\n<blockquote>\n<p style=\"text-align: left; color: #88a6a4;\">\u672c\u6587\u5730\u5740\uff1a<a href=\"http:\/\/lrxjmw.cn\/understand-iowait.html\" target=\"_blank\" rel=\"noopener\">http:\/\/lrxjmw.cn\/understand-iowait.html<\/a><span style=\"float: right;\">\u7f16\u8f91\uff1a\u9b4f\u4e3d\u733f\uff0c\u5ba1\u6838\u5458\uff1a\u5f20\u5b8f\u5b87<\/span><\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p>%iowait \u662f \u201csar -u\u201d \u7b49\u5de5\u5177\u68c0\u67e5CPU\u4f7f\u7528\u7387\u65f6\u663e\u793a\u7684\u4e00\u4e2a\u6307\u6807\uff0c\u5728Linux\u4e0a\u663e\u793a\u4e3a %iowa [&hellip;]<\/p>\n","protected":false},"author":317,"featured_media":6030,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[55],"tags":[],"class_list":["post-6025","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-thread"],"acf":[],"_links":{"self":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/6025","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/users\/317"}],"replies":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/comments?post=6025"}],"version-history":[{"count":7,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/6025\/revisions"}],"predecessor-version":[{"id":245235,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/6025\/revisions\/245235"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/media\/6030"}],"wp:attachment":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/media?parent=6025"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/categories?post=6025"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/tags?post=6025"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}