Hibernate ubuntu 20.04

Hibernate ubuntu 20.04

First of all, you should increase the size of the /swapfile at least to the size of your RAM.
link: https://linuxhint.com/change_swap_size_ubuntu/

Install dependencies:
`sudo apt install pm-utils hibernate uswsusp`

Find your UUID of swap file:
`findmnt -no UUID -T /swapfile`

get offset 
`sudo filefrag -v /swapfile |grep " 0:"| awk '{print $4}'` 

Edit /etc/default/grub and replace the string

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
with your UUID and offset:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash resume=UUID=371b1a95-d91b-49f8-aa4a-da51cbf780b2 resume_offset=23888916"

Update GRUB:

`sudo update-grub`

Test your hibernation:

`sudo systemctl hibernate`

helpful link :https://ubuntuhandbook.org/index.php/2021/08/enable-hibernate-ubuntu-21-10/


After doing this if it still does not work. you can hibernate using `pm-hibernate`

follow this guide: https://help.ubuntu.com/community/PowerManagement/Hibernate#uswsusp
- install the package from here: https://packages.ubuntu.com/focal/amd64/uswsusp/download

- install pm-utils using `apt install pm-utils` 
- check with s2disk if the hibernate works. 
- Then configure pm-hibernate to use s2disk to hibernate. 
   edit /etc/pm/config.d/00sleep_module and change the value of SLEEP_MODULE:
   ```
   SLEEP_MODULE="uswsusp"
   ```
   https://askubuntu.com/a/1405996/1591767
   https://blog.ivansmirnov.name/how-to-set-up-hibernate-on-ubuntu-20-04/