Enabling Hibernate on Linux (Debian-based & Fedora)

Overview

Hibernate saves the entire RAM state to disk and powers off the machine. When you power it back on, the system restores exactly where you left off.

For hibernate to work properly:

• Swap must exist
• Swap size should be >= RAM
• The kernel must know where the swap is

Debian-based distributions

Examples: Ubuntu, Linux Mint, Pop!_OS.

Check swap

swapon --show

If nothing appears, you need to create swap. Check RAM:

free -h

Recommended: swap >= RAM.

Find swap UUID

blkid

Example output:

/dev/sda3: UUID="xxxx-xxxx" TYPE="swap"

Copy the UUID.

Configure GRUB

Edit the GRUB config:

sudo nano /etc/default/grub

Find:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Change to:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash resume=UUID=YOUR_SWAP_UUID"

Update GRUB

sudo update-grub

Test hibernate

systemctl hibernate

Fedora

Fedora uses Dracut instead of initramfs-tools, so the process differs slightly.

Check swap

swapon --show

Find swap UUID

blkid

Add the resume parameter

Edit the GRUB config:

sudo nano /etc/default/grub

Modify:

GRUB_CMDLINE_LINUX="resume=UUID=YOUR_SWAP_UUID"

Rebuild GRUB

BIOS systems:

sudo grub2-mkconfig -o /boot/grub2/grub.cfg

UEFI systems:

sudo grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg

Rebuild initramfs

sudo dracut -f

Test hibernate

systemctl hibernate

Troubleshooting

Check if the system supports hibernate:

cat /sys/power/state

If disk appears, hibernate is supported. Check the log:

journalctl -b

Notes

• Swap must be large enough for RAM
• A swapfile works, but a swap partition is more reliable
• Secure Boot may sometimes interfere with resume