{"id":453,"date":"2016-06-30T13:07:09","date_gmt":"2016-06-30T12:07:09","guid":{"rendered":"http:\/\/www.flat-planet.net\/?p=453"},"modified":"2016-06-30T13:11:42","modified_gmt":"2016-06-30T12:11:42","slug":"handling-bad-ram-in-linux","status":"publish","type":"post","link":"https:\/\/flat-planet.net\/?p=453","title":{"rendered":"Handling bad RAM in Linux"},"content":{"rendered":"<p>After some recent hardware upgrades, I was getting some strange crashes (different to the freeze that accompanies the intermittently-failing HDD that I&#8217;m trying to hunt down), specifically referring to Bad swap offsets and Bad page maps.<\/p>\n<p>Given that I fired up memtest86+ and let it do it&#8217;s thing&#8230; and\u00a0 it turns out that I have a few chunks of dodgy RAM. RMA time &#8211; though be sure to try swapping the RAM around and make sure the problem follows the stick and not the slot.!<\/p>\n<p><a href=\"https:\/\/www.flat-planet.net\/wp-content\/uploads\/2016\/06\/IMG_20160629_203812.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-454\" src=\"https:\/\/www.flat-planet.net\/wp-content\/uploads\/2016\/06\/IMG_20160629_203812.jpg\" alt=\"Memtest86\" width=\"640\" height=\"365\" \/><\/a>But to keep everything up and running in the meantime I decided to use memmap to block off that chunk of memory while linux is booting. To do this modify \/etc\/default\/grub:<\/p>\n<pre class=\"brush: bash; title: ; notranslate\" title=\"\">\r\nGRUB_DEFAULT=0\r\nGRUB_TIMEOUT=5\r\nGRUB_DISTRIBUTOR=`lsb_release -i -s 2&amp;amp;gt; \/dev\/null || echo Debian`\r\nGRUB_CMDLINE_LINUX_DEFAULT=&quot;quiet memmap=1440M\\\\\\$2048M&quot;\r\nGRUB_CMDLINE_LINUX=&quot;&quot;\r\n<\/pre>\n<p>Basically what we are doing here is telling linux to block off 1440M of RAM, starting at 2048M. Then run sudo update-grub, reload and you will see your &#8216;free -m&#8217; memory drop to about 6.5G.<\/p>\n<p>This should tide you over, and prevent some random crashes until replacement RAM arrives<\/p>\n","protected":false},"excerpt":{"rendered":"<p>After some recent hardware upgrades, I was getting some strange crashes (different to the freeze that accompanies the intermittently-failing HDD that I&#8217;m trying to hunt down), specifically referring to Bad swap offsets and Bad page maps. Given that I fired up memtest86+ and let it do it&#8217;s thing&#8230; and\u00a0 it turns out that I have [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[38],"tags":[42,276,277,278,279,280,21,32],"series":[],"class_list":["post-453","post","type-post","status-publish","format-standard","hentry","category-linux","tag-linux-2","tag-ram","tag-bad-ram","tag-memtest","tag-memmap","tag-memtest86","tag-problems","tag-simple-things"],"_links":{"self":[{"href":"https:\/\/flat-planet.net\/index.php?rest_route=\/wp\/v2\/posts\/453","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/flat-planet.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/flat-planet.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/flat-planet.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/flat-planet.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=453"}],"version-history":[{"count":2,"href":"https:\/\/flat-planet.net\/index.php?rest_route=\/wp\/v2\/posts\/453\/revisions"}],"predecessor-version":[{"id":456,"href":"https:\/\/flat-planet.net\/index.php?rest_route=\/wp\/v2\/posts\/453\/revisions\/456"}],"wp:attachment":[{"href":"https:\/\/flat-planet.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=453"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/flat-planet.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=453"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/flat-planet.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=453"},{"taxonomy":"series","embeddable":true,"href":"https:\/\/flat-planet.net\/index.php?rest_route=%2Fwp%2Fv2%2Fseries&post=453"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}