Hibernation Setup Script for Omarchy (Btrfs + Limine)

This script automates the complete setup of hibernation on an Omarchy installation with a Btrfs root filesystem and the Limine bootloader.

Overview

The script performs the following actions:

• Creates a dedicated Btrfs subvolume at /swap.
• Creates a swapfile within the subvolume, sized to match the system's total RAM.
• Adds a corresponding low-priority swap entry to /etc/fstab.
• Ensures the resume hook is present in the mkinitcpio configuration.
• Calculates the swap file's physical offset and configures kernel resume parameters.
• Updates /etc/default/limine with resume and resume_offset parameters.
• Refreshes the initramfs and bootloader configuration using limine-update.

⚠️ Important: Btrfs-Only Support

This script is designed exclusively for Btrfs filesystems and will NOT work with other filesystems (ext4, XFS, etc.). It is intended specifically for Omarchy installations (as of August 29, 2025), which use Btrfs by default. The script uses Btrfs-native swapfile creation (btrfs filesystem mkswapfile) and automatically calculates the required resume_offset parameter for proper hibernation support.

If you are not using Btrfs, this script will fail during the filesystem check and you will need a different hibernation setup approach.

Requirements

• System: An Omarchy installation.
• Filesystem: A Btrfs root filesystem.
• Bootloader: Limine bootloader installed and configured:
  • /boot/EFI/limine/limine.conf must be present
  • /etc/default/limine must be present for kernel cmdline configuration
• Systemd: The systemd-hibernate-resume-generator must be available.
• mkinitcpio: The omarchy_hooks.conf file must be present at /etc/mkinitcpio.conf.d/omarchy_hooks.conf.
• Tools: btrfs-progs (with filesystem mkswapfile), filefrag, sed, numfmt, and limine-update must be installed.

Usage

• Real run (makes changes):

  sudo ./hibernate.sh

• Dry run (no changes, prints actions):

  DRY_RUN=1 ./hibernate.sh

• Updating the swapfile: If you change the amount of RAM in your system, you will need to recreate the swapfile. You can do this with the --update flag:

  sudo ./hibernate.sh --update

• Getting help: To see the available commands, use the --help flag:

  ./hibernate.sh --help

Notes

• The script will not run if /swap or /swap/swapfile already exist.
• The script will abort if any non-zram swap is already active.
• The script creates timestamped backups of /etc/fstab and the mkinitcpio hooks file before modifying them.

Testing Hibernation

After a successful real run, test hibernation with the following command:

systemctl hibernate

Troubleshooting

• Ensure that btrfs filesystem mkswapfile is available (requires a recent version of btrfs-progs).
• If limine-update is missing, install and configure Limine properly or adjust the script for your boot setup.
• If your mkinitcpio hooks file path differs, update the HOOKS_CONF_PATH variable in hibernate.sh.

Disclaimer

This script modifies system files and can potentially lead to data loss or an unbootable system. Use it at your own risk. It is highly recommended to perform a dry run and back up your data before running the script.