Comment 39 for bug 1499556

<b>Workaround</b> and update that may aid in debugging.

I have learned recently (through extensive testing) that pm-hibernate works flawlessly! As a workaround I set KDE to hibernate when the power button is pressed and not ask for a password on resume. Now I can press the power button and the machine "hibernates" which, for some reason, successfully gets the computer to poweroff instead of just rebooting.

I followed this guide to enable hibernation on KDE in Ubuntu 14.04 LTS: https://help.ubuntu.com/14.04/ubuntu-help/power-hibernate.html Don't forget you have to reboot the machine before the settings take effect, and I had to set the .pkla file rwx for everybody (i.e., sudo chmod 777 /etc/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla ). Then it worked great.

The settings for the power button in KDE are in systemsettings -> power management -> energy saving and systemsettings -> power management -> advanced settings

Please keep me posted if this bug every gets fixed, but I'm happy to have found a better workaround than always holding the power button for 5 seconds to force a poweroff.