14.04 and beyond

Mitch points out in his answer for 14.04 and 16.04 that you should check 10-vendor.d/com.ubuntu.desktop.pkla before modifying anything. Also check that you have Secure Boot disabled and if that brings the menu option back.

Re-enabling the hibernation option in the menu

To re-enable the hibernation option in the menu, your /etc/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla should be modified to look like the following in saucy (13.10):

[Re-enable hibernate by default in upower]
Identity=unix-user:*
Action=org.freedesktop.upower.hibernate
ResultActive=yes

[Re-enable hibernate by default in logind]
Identity=unix-user:*
Action=org.freedesktop.login1.hibernate
ResultActive=yes

Then reboot or run killall indicator-session-service in your session and you should have your hibernate functionality/menu option back. Create the file if it doesn't exist already.

Investigation from bug report

Citation from Jeffery To's post on Launchpad Bug Report #1232814:

For Saucy, indicator-session was updated to use logind (org.freedesktop.login1) instead of upower.

If you check /var/lib/polkit-1/localauthority/10-vendor.d/com.ubuntu.desktop.pkla, you'll see that hibernate is disabled by default in both upower and logind.

So the first step to re-enable the Hibernate option is to edit /etc/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla to something like:

[Re-enable hibernate by default in upower]
Identity=unix-user:*
Action=org.freedesktop.upower.hibernate
ResultActive=yes

[Re-enable hibernate by default in logind]
Identity=unix-user:*
Action=org.freedesktop.login1.hibernate
ResultActive=yes

After rebooting, the login screen session menu should have a Hibernate option.

[...]

All thanks and credit go to Jeffery!

Why was hibernation disabled?

There exists a bug report on launchpad that suggests disabling suspend/hibernate instead of tracking which hardware "certifies" for which power modes. It's claimed to be a more scalable approach.

Another thing to mention is that using UEFI Secure Boot and hibernation appears to be possible but may be a risk to circumvent the former. (1, 2) As a reminder, when you use hibernation you store everything in RAM to disk without encryption, this includes passwords for encrypted filesystems and containers.

At some point with 16.04 I had to disable Secure Boot to be able to hibernate my laptops. In my case I used uswsusp and testing with s2disk returned the message below. This may give you a hint that your issue, why you can't hibernate although everything else is in place, is related to Secure Boot:

s2disk: Could not open the snapshot device. Reason: Operation not permitted 

However, please understand that this is not a place to complain and please be nice.

Related questions

• How can I tell Ubuntu to do nothing when I close my laptop lid? (or tell Ubuntu to hibernate when closing the laptop lid)

Found the answer myself. It's a bug. More info here:

https://bugs.launchpad.net/ubuntu/+source/kde-workspace/+bug/1124149

What worked for me was to edit powerbutton.sh

sudo nano /etc/acpi/powerbtn.sh

and change the last line

/sbin/shutdown -h now "Power button pressed"

to

:: /sbin/shutdown -h now "Power button pressed"