How do I hibernate in Ubuntu 20.04?

Question

I have used Windows a couple years. Sometimes I had to shutdown laptop because of power loss or travel and the hibernate feature helped me. Now after switching to Ubuntu I found there is no hibernate feature. I have read some questions specifically this one. How to enable hibernate option in Ubuntu 20.04? Now after reading this guy's answer as he told I should have swap partition not swap file. Now unfortunately I have swap file. Now what if I wanted to hibernate WITH the swap file?

Answer 1

To enable Hibernation in 20.04 using Swapfile:

Increase swapfile size to match RAM size up to 8GB.

• Check the swap that is in use:

  sudo swapon -s
  

• If swap partition(s) are found:

  sudo swapoff -a
  sudo nano -Bw /etc/fstab
  

• Add # before the UUID of the swap partition(s):

  # UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX   none   swap    sw     0       0
  

• Add a line for the swapfile, if one does not exist:

  /swapfile   none    swap     sw      0       0
  

• Create the swapfile:

  sudo fallocate -l XG /swapfile*
  

  where X is swapfile's size in GB:

  sudo mkswap /swapfile
  sudo chmod 0600 /swapfile
  sudo swapon /swapfile
  

• Reboot:

  sudo reboot
  

Add resume location and offset to grub.cfg:

• Edit /etc/default/grub:

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash resume=UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX resume_offset=XXXXX"
  

• Use UUID from root.

• Use offset from:

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

• Update GRUB:

  sudo update-grub
  

• Test hibernation:

  sudo systemctl hibernate
  

A hibernate button can be added using GNOME extensions.

Note that there is a slight possibility of getting holes in a swapfile when creating it with fallocate. /var/log/syslog can be searched for the phrase swapon: swapfile has holes to ensure there will be no data loss.

A swap file can alternatively be created using dd:

sudo dd if=/dev/zero of=/swapfile bs=1G count=8

An error when using dd may overwrite your HDD.

Answer 2

to continue this answer, in my case, after doing with grub, it did not work, so I added a file to initramfs-tools config with the below content:

# write the resume UUID (make sure to replace this with your UUID)
echo RESUME=UUID=<Swap Device UUID> > /etc/initramfs-tools/conf.d/resume
regenerate initramfs
sudo update-initramfs -c -k all

Answer 3

Hibernating is very fragile, and requires both operating system and driver support, both in linux and in windows. If any part of the system doesn't support hibernation, it won't work. Best case, it disables it and doesn't offer the option; worst case, the hibernation fails and you end up rebooting anyway, possibly after finding out some devices don't work correctly on wake up.

An answer in the question you linked to explains how to use a swapfile for hibernation. However, you must satisfy several different conditions for this to work, and if any of them are not met, it will fail.