{
  "date": "2018-06-26T15:37:09",
  "slug": "kernel-panic-not-syncing-out-of-memory-and-no-killable-processes",
  "link": "https://www.dbi-services.com/blog/kernel-panic-not-syncing-out-of-memory-and-no-killable-processes/",
  "title": {
    "rendered": "Kernel panic – not syncing: Out of memory and no killable processes"
  },
  "content": {
    "rendered": "<h2>By Franck Pachot</h2>\n<p>.<br />\nThis is a quick post to give a solution (maybe not the best one as this was just quick troubleshooting) if, at boot, you see something like:</p>\n<pre><code>Trying to allocate 1041 pages for VMLINUZ [Linux=EFI, setup=0x111f, size=0x41108d01]</code></pre>\n<p>and then:</p>\n<pre><code>Kernel panic - not syncing: Out of memory and no killable processes\nPid: 1228 comm: kworker Not tainted 3.8.13-118.17.4.el6uek.x86_64 #2</code></pre>\n<p><!--more--><br />\n<a href=\"https://www.dbi-services.com/blog/wp-content/uploads/sites/2/2022/04/IMG_E5543.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"https://www.dbi-services.com/blog/wp-content/uploads/sites/2/2022/04/IMG_E5543.jpg\" alt=\"IMG_E5543\" width=\"225\" height=\"300\" class=\"alignright size-medium wp-image-24599\" /></a><br />\nIf you do not see the messages, then you may need to remove the &#8216;quiet&#8217; option of kernel and replace it by &#8216;nosplash&#8217; &#8211; this is done from grub.</p>\n<p>So, there&#8217;s not enough memory to start the kernel. I got this from a server that had been shut down to be moved to another data center, so at first, I checked that the RAM was ok. Actually, the problem was with the configuration of hugepages (vm.nr_hugepages in /etc/sysctl.conf) which was allocating nearly the whole RAM. Probably because the setting has been erroneously changed without checking /proc/meminfo.</p>\n<p>So, without any clue about what the problem was, I started by forcing the kernel to use 4GB (instead of getting it from hardware info). This is done by pressing any key on the GRUB menu, &#8216;e&#8217; to edit, add the &#8216;mem=4g&#8217;. Then the boot was ok. Of course, if the server tries to start the Oracle instances, the systems starts to swap so better change also the runlevel.</p>\n<p>This is sufficient to check the huge pages allocation and ensure that you leave enough memory for at least the kernel (but also consider also the system, the PGA, &#8230;). So don&#8217;t forget that the mem= option, usually there to give a maximum limit, may be useful also to guarantee a minimum of RAM for the kernel.</p>\n",
    "protected": false
  }
}