How to use disable cgroupv2

What are cgroups?

Cgroups or control groups allow you to allocate resources like CPU or memory to a group of tasks. For more in depth about cgroups read this

Why would I want to move to cgroupv1

In my case, I wanted to run judge0 on Amazon Linux 2023 but saw this issue

Disabling on Ubuntu

sudo nano /etc/default/grub
# edit this line, and save:
GRUB_CMDLINE_LINUX="systemd.unified_cgroup_hierarchy=0"
sudo update-grub
sudo reboot

Disabling on Amazon Linux

Instead of manually editing the config, I used an EC2 launch template that would create my EC2 instances with cgroupsv1 enabled by default

Steps:

• Navigate to EC2 -> Launch Templates
• Pick an Amazon Linux AMI of your choice
• In Advanced details -> User Data paste this in

#!/bin/bash
grubby --update-kernel=ALL --args="systemd.unified_cgroup_hierarchy=0"

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