Ubuntu LTS 18.04 Computer Locks Up when Entering Sleep Mode

Does your Ubuntu Computer lock up when entering sleep mode?

Any Dell computer locks up when put into sleep after installing Canonical's 18.04 ISO image. The computer must be power cycled in order to restore full functionality.

All the following three statements must be true for this issue to occur. If they do, then see the following section for a resolution:

• The computer must be using the Canonical 18.04 public ISO image
• The computer must have the nVidia graphics driver installed and in use
• The computer must be set to [s2idle] in /sys/power/mem_sleep (This is the default setting for this Operating System.)

Dell's engineering department confirms that if any of the three stated conditions in the symptoms does not happen, then the problem does not occur. They identified several different ways that you can change these conditions to resolve the problem on your computer:

• You can revert to the operating system that shipped with your computer.

• If the computer shipped with Ubuntu, then install the operating system from the Dell Ubuntu OEM ISO. It does not exhibit the same behavior.

• You can replace the Nvidia driver in the operating system with the Nouveau open-source driver.

• You can go to /sys/power/mem_sleep in Terminal and change it from [s2idle] to [deep]

  1. Due to file read and write permissions, typing the following command in Terminal gives root admin rights to your command: (You must be part of the administrator's group on the computer and have the correct password.)

     sudo -s

  2. Typing the next command lets you edit the file:

     echo deep > /sys/power/mem_sleep