hasenj blog

Strange hibernation problem in Xubuntu

Posted in linux by hasen on 31/08/2009

I’ve been having a problem with my xubuntu when it hibernates automatically after running out of battery power. The problem is, it doesn’t wake up properly. It gets stuck at some point, and it stops dead there.

Today when I woke it up I choose the recovery mode option from the grub menu so it shows the boot info in text mode (instead of showing the xubuntu splash). The last line before it locks up said:

Suspending console(s) (use no_console_suspend to debug)

So, I tried to hibernate manually and wake up with this option on. To be honest I didn’t really know how to “use” this option; I just wrote it in the grub loader in the spot where you can add extra parameters. This time it booted fine, but I got a feeling maybe it had nothing to do with that. So I hibernated manually again but this time let it wakeup normally; and it did. It woke up normally just find.

So, I figured the problem only happens when it automatically hibernates from low battery. I went to the xfce-power-manager preferences (by right clicking on the battery icon in the systray (notification area)) and tried to see if something is causing that. I noticed the monitor is set to turn off in 5 minutes when on running on battery power.

Well, it’s not just a turn off option. There are three settings for the monitor when running on battery power:

Stand by after: [ x minutes ]
Suspend after: [ x minutes ]
Turn off after: [ x minutes ]

They were all set to like 5 or 10 minutes. This smelled bad for me: how do I turn the monitor back on?? So I just disabled them all (by setting them to 0 minutes which means never).

Then I took let the laptop run on battery power until it ran out and hibernated itself. I plugged it back and woke it up, and it woke up just fine.

I think the culprit was these monitor settings which I turned off.