Ubuntu – black screen on Suspend

This is actually a simple one:

Add pm-suspend --quirk-dpms-on to the /var/cache/pm-utils/last_known_working.quirkdb file.

Reboot and it should work flawlessly.

If you don't have enough space on your swap partition, you might get a black screen when you awaken your system from hibernation. The black screen used to happen to me, until I decided to sacrifice the necessary hard drive space for Suspend-to-Disk (hibernation).

Your swap partition needs to be at least as big as your RAM size.

This is covered in the The Official Ubuntu Swap FAQ:

Hibernation (suspend-to-disk) The hibernation feature (suspend-to-disk) writes out the contents of RAM to the swap partition before turning off the machine. Therefore, your swap partition should be at least as big as your RAM size. The hibernation implementation currently used in Ubuntu, swsusp, needs a swap or suspend partition. It cannot use a swap file on an active file system.

Here's a table of example swap partitions, relative to RAM size, taken from The Official Ubuntu Swap FAQ. They recommend a swap partition a little bigger then your RAM.

(last 3 columns denote swap space)

        RAM(MB) No hibernation  With Hibernation  Maximum
         256     256              512               512
         512     512             1024              1024
        1024    1024             2048              2048

        RAM(GB) No hibernation  With Hibernation  Maximum
          1      1                2                   2
          2      1                3                   4
          3      2                5                   6
          4      2                6                   8
          5      2                7                  10
          6      2                8                  12
          8      3               11                  16
         12      3               15                  24
         16      4               20                  32
         24      5               29                  48
         32      6               38                  64
         64      8               72                 128
        128     11              139                 256

If you don't have enough swap space, then Suspend-to-Disk will not work.

Click this link to learn how to increase your swap space.