{"id":4910,"date":"2015-06-04T12:20:27","date_gmt":"2015-06-04T04:20:27","guid":{"rendered":"http:\/\/rmohan.com\/?p=4910"},"modified":"2015-06-04T12:20:27","modified_gmt":"2015-06-04T04:20:27","slug":"changing-default-io-scheduler-linux","status":"publish","type":"post","link":"https:\/\/mohan.sg\/?p=4910","title":{"rendered":"Changing default IO scheduler linux"},"content":{"rendered":"<p>Change default Linux IO scheduler to optimize IOs (very important if server is VM)<\/p>\n<p>Check existing (active) io scheduler (elevator):<\/p>\n<p>[root@server ~]# cat \/sys\/block\/sda\/queue\/scheduler<br \/>\nnoop anticipatory deadline [cfq] # cfq active<\/p>\n<p>[root@server ~]# cat \/sys\/block\/sda\/queue\/scheduler<br \/>\nnoop anticipatory deadline [cfq] # cfq active<\/p>\n<p>Change it on the fly<\/p>\n<p>[root@server ~]# echo noop &gt; \/sys\/block\/sda\/queue\/scheduler<\/p>\n<p>[root@server ~]# echo noop &gt; \/sys\/block\/sda\/queue\/scheduler<\/p>\n<p>[root@server ~]# echo deadline &gt; \/sys\/block\/sda\/queue\/scheduler<br \/>\n[root@server ~]# echo deadline &gt; \/sys\/block\/sda\/queue\/scheduler<\/p>\n<p>Change it permanently<\/p>\n<p>Append elevator=deadline to the end of the grub.cfg kernel line and reboot<br \/>\ntitle CentOS<br \/>\nroot (hd0,0)<br \/>\nkernel \/vmlinuz-2.6.32-279.19.1.el6.x86_64 ro root=\/dev\/mapper\/vg-lv_root &#8230; elevator=deadline<br \/>\ntitle CentOS<br \/>\nroot (hd0,0)<br \/>\nkernel \/vmlinuz-2.6.32-279.19.1.el6.x86_64 ro root=\/dev\/mapper\/vg-lv_root &#8230; elevator=deadline<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Change default Linux IO scheduler to optimize IOs (very important if server is VM)<\/p>\n<p>Check existing (active) io scheduler (elevator):<\/p>\n<p>[root@server ~]# cat \/sys\/block\/sda\/queue\/scheduler noop anticipatory deadline [cfq] # cfq active<\/p>\n<p>[root@server ~]# cat \/sys\/block\/sda\/queue\/scheduler noop anticipatory deadline [cfq] # cfq active<\/p>\n<p>Change it on the fly<\/p>\n<p>[root@server ~]# echo noop &gt; \/sys\/block\/sda\/queue\/scheduler<\/p>\n<p>[root@server ~]# [&#8230;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"_links":{"self":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/4910"}],"collection":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4910"}],"version-history":[{"count":1,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/4910\/revisions"}],"predecessor-version":[{"id":4911,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/4910\/revisions\/4911"}],"wp:attachment":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4910"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4910"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4910"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}