There was a problem loading the comments.

Missing memory in CentOS 8

Support Portal  »  Knowledgebase  »  Viewing Article

  Print
If you purchased a CentOS 8 VPS on our cloud platform, you may have noticed 150-200 MB of available RAM missing on your machine.

This is caused by CentOS 8 enabling kdump by default. The kdump package essentially runs a 2nd kernel in CentOS 8 to collect crash dump logs in the event of a system crash, and reserves about 150 MB of RAM for itself. You can learn more about kdump and whether or not you need it for your setup here: https://en.wikipedia.org/wiki/Kdump_(Linux)

To disable kdump to reclaim your additional space, you'll need to run a few commands, and reboot your machine.

1st, Edit /etc/default/grub, and on go to the line that starts with GRUB_CMDLINE_LINUX=. Change crashkernel=auto to crashkernel=no. When finished, the line should look like this:
GRUB_CMDLINE_LINUX="console=ttyS0,115200n8 no_timer_check net.ifnames=0 crashkernel=no"

2nd: Update your grub.cfg file:
sudo grub2-mkconfig -o /boot/grub2/grub.cfg

3rd: DIsable the kdump service from starting:
sudo systemctl disable kdump

4th: Reboot your system
sudo reboot

Upon reboot, you should now see the full 1 GB of RAM available to your VM.

If you have any issues, please don't hesitate to open a support ticket, and an engineer from our team will be happy to assist.

Share via
Did you find this article useful?  

Related Articles

© TeraSwitch Inc.