[ubuntu] Activate the hibernate button/option

Problem

A fresh install of Ubuntu does not sport the hibernate option/button.

Solution not working for me

Presumtion is that you use a swap partition and no swap file (alone, not sure a combination works). Make sure, your swap is at least as big as your memory. You can check with

free -h

In /etc/systemd/logind.conf the hibernate key must be handled by the uncommented line:

HandleHibernateKey=handle-hibernate-key

Activate the setting with

update-initramfs -u

Make sure in /etc/default/grubthere is an entry for your resume partition like

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash resume=/dev/dm-0"

You then need to update the grub configuration.

update-grub

Then reboot.