{"id":1524,"date":"2015-05-20T21:29:59","date_gmt":"2015-05-21T03:29:59","guid":{"rendered":"http:\/\/www.supportpro.com\/blog\/?p=1524"},"modified":"2026-04-20T01:13:27","modified_gmt":"2026-04-20T07:13:27","slug":"unable-to-fork-cannot-allocate-memory","status":"publish","type":"post","link":"https:\/\/www.supportpro.com\/blog\/unable-to-fork-cannot-allocate-memory\/","title":{"rendered":"OpenVZ Fix: Unable to Fork Error &#8216;Cannot Allocate Memory Solution&#8217;"},"content":{"rendered":"\n<h4 class=\"wp-block-heading\">Issue Description<\/h4>\n\n\n\n<p>While trying to access an OpenVZ container using the following command:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>vzctl enter 10524<\/code><\/pre>\n\n\n\n<p>you may encounter this error:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Unable to fork: Cannot allocate memory<\/code><\/pre>\n\n\n\n<p>Here, <code>10524<\/code> refers to the container ID.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Step 1: Check Node Memory Availability<\/h4>\n\n\n\n<p>First, verify whether the host node is running out of memory:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>free -m<\/code><\/pre>\n\n\n\n<p>If the system shows sufficient free memory, the issue is likely not at the node level.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Step 2: Check Resource Limits (privvmpages)<\/h4>\n\n\n\n<p>If memory is not the issue, the problem is usually related to <strong>OpenVZ memory limits<\/strong>, especially <code>privvmpages<\/code>.<\/p>\n\n\n\n<p>Check current resource usage:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>cat \/proc\/user_beancounters<\/code><\/pre>\n\n\n\n<p>This file contains resource usage and limits for all containers.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Step 3: Identify the Problem Container<\/h4>\n\n\n\n<p>Locate the entry for container <strong>10524<\/strong> and check the <code>privvmpages<\/code> values:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>If <strong>failcnt is high or non-zero<\/strong><\/li>\n\n\n\n<li>And memory is marked as <strong>exhausted<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Then the container has hit its memory limit.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Step 4: Increase privvmpages Limit<\/h4>\n\n\n\n<p>Edit the container configuration file:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>vim \/etc\/sysconfig\/vz-scripts\/10524.conf<\/code><\/pre>\n\n\n\n<p>Find the <code>privvmpages<\/code> parameter and increase its value.<\/p>\n\n\n\n<p>Example:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>PRIVVMPAGES=\"unlimited:unlimited\"<\/code><\/pre>\n\n\n\n<p>or set a higher limit based on server capacity.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Step 5: Restart the Container<\/h4>\n\n\n\n<p>Apply the changes by restarting the container:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>vzctl restart 10524<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">Conclusion<\/h3>\n\n\n\n<p>The \u201cUnable to fork: Cannot allocate memory\u201d error in OpenVZ is typically caused by exhausted <strong>privvmpages limits<\/strong>, not always system-wide memory issues. Increasing the container\u2019s memory allocation resolves the issue in most cases.<\/p>\n\n\n\n<p>If you require help, <a href=\"https:\/\/www.supportpro.com\/requestquote.php\">contact SupportPRO Server Admin<\/a><\/p>\n\n\n\n<p class=\"has-text-align-center\"><span id=\"hs-cta-wrapper-9d590242-d641-4383-94b4-8cfd62f0af6b\" class=\"hs-cta-wrapper\"><span id=\"hs-cta-9d590242-d641-4383-94b4-8cfd62f0af6b\" class=\"hs-cta-node hs-cta-9d590242-d641-4383-94b4-8cfd62f0af6b\"><a href=\"https:\/\/www.supportpro.com\/freecheckup.php\"><\/a><\/span><\/span><\/p>\n\n\n\n<div class=\"wp-block-media-text alignwide has-media-on-the-right is-stacked-on-mobile is-vertically-aligned-center has-white-background-color has-background\"><div class=\"wp-block-media-text__content\">\n<p class=\"has-large-font-size\">Facing issues? <\/p>\n\n\n\n<p class=\"has-large-font-size\">Our technical support<br>engineers can solve it. <\/p>\n\n\n\n<!--HubSpot Call-to-Action Code --><span class=\"hs-cta-wrapper\" id=\"hs-cta-wrapper-3350a795-db50-482f-9911-301930d1b1be\"><span class=\"hs-cta-node hs-cta-3350a795-db50-482f-9911-301930d1b1be\" id=\"hs-cta-3350a795-db50-482f-9911-301930d1b1be\"><!--[if lte IE 8]><div id=\"hs-cta-ie-element\"><\/div><![endif]--><a href=\"https:\/\/cta-redirect.hubspot.com\/cta\/redirect\/2725694\/3350a795-db50-482f-9911-301930d1b1be\" ><img decoding=\"async\" class=\"hs-cta-img\" id=\"hs-cta-img-3350a795-db50-482f-9911-301930d1b1be\" style=\"border-width:0px;\" src=\"https:\/\/no-cache.hubspot.com\/cta\/default\/2725694\/3350a795-db50-482f-9911-301930d1b1be.png\"  alt=\"Contact Us today!\"\/><\/a><\/span><script charset=\"utf-8\" src=\"https:\/\/js.hscta.net\/cta\/current.js\"><\/script><script type=\"text\/javascript\"> hbspt.cta.load(2725694, '3350a795-db50-482f-9911-301930d1b1be', {\"useNewLoader\":\"true\",\"region\":\"na1\"}); <\/script><\/span><!-- end HubSpot Call-to-Action Code -->\n<\/div><figure class=\"wp-block-media-text__media\"><img fetchpriority=\"high\" decoding=\"async\" width=\"904\" height=\"931\" src=\"https:\/\/www.supportpro.com\/blog\/wp-content\/uploads\/2022\/09\/Free-server-checkup.png\" alt=\"guy server checkup\" class=\"wp-image-12943 size-full\" srcset=\"https:\/\/www.supportpro.com\/blog\/wp-content\/uploads\/2022\/09\/Free-server-checkup.png 904w, https:\/\/www.supportpro.com\/blog\/wp-content\/uploads\/2022\/09\/Free-server-checkup-291x300.png 291w, https:\/\/www.supportpro.com\/blog\/wp-content\/uploads\/2022\/09\/Free-server-checkup-768x791.png 768w, https:\/\/www.supportpro.com\/blog\/wp-content\/uploads\/2022\/09\/Free-server-checkup-585x602.png 585w\" sizes=\"(max-width: 904px) 100vw, 904px\" \/><\/figure><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Issue Description While trying to access an OpenVZ container using the following command: you may encounter this error: Here, 10524 refers to the container ID. Step 1: Check Node Memory&hellip;<\/p>\n","protected":false},"author":5,"featured_media":16947,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"","_lmt_disable":"","footnotes":""},"categories":[6,7],"tags":[],"class_list":["post-1524","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-linux-basics","category-server-tweaking"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/posts\/1524","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/comments?post=1524"}],"version-history":[{"count":4,"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/posts\/1524\/revisions"}],"predecessor-version":[{"id":16948,"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/posts\/1524\/revisions\/16948"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/media\/16947"}],"wp:attachment":[{"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/media?parent=1524"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/categories?post=1524"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.supportpro.com\/blog\/wp-json\/wp\/v2\/tags?post=1524"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}