Since I purchased my notebook and mentioned that I installed Fedora Linux 5 on it, I’ve been getting a lot of quesitons from people everywhere. One of the most frequent questions is “Does hybernate work?”.
You have to understand that this is my first notebook. At least in this century. So I am not very updated on the terminology and technologies involved. Trying to find out what ‘hybernate’ really is showed that different people mean different things.
There are many resources on the web that try to clear up the confusion. After going through a few of them, I came to realize that there are at least two separate terms here – ‘hybernate’ and ‘suspend’.
‘Hybernate’ is a mode in which your notebook (or some other mobile device) saves the current state to hard disk and switches off. Nex time you start it, last working state is loaded from the hard disk and you go straight to all your applications, windows, etc. This is a handy feature. But going to and from hybernate mode takes a couple of minutes.
‘Suspend’ is very similar, but instead of using the hard disk, it uses RAM (memory). Saving current state and loading last working state is much much faster, but there is a trade off. RAM gets erased every time a computer starts, so, when in ‘suspend’ mode, your notebook is using a little bit of battery power to keep the RAM going.
Linux has supported both hybernation and suspension for quite some time. Setting it up though wasn’t trivial. Or so they say. Things like kernel compilation, source patching and driver installation had to be done.
This had improved. At least in Fedora Linux 5. All I had to do was login to KDE, start Control Center (kcontrol), navigate to ‘Power Control’ section, choose ‘Laptop Batter’ and enable all checkboxes. Right after I did it (no need to reboot even), I got a few more menu items (right click on battery monitor in the taskbar). ‘Hybernate’ and ‘Suspend’ both were in.
First I tried ‘hybernate’. It worked great – my current state was saved and the computer shut down. When I switched it back on, during the boot sequence it realized that it was in hybernation and loaded saved working state. All applications came up correct, windows were in the right places and it all looked like I never leaved. Even my wireless network was working.
I wasn’t so lucky with ‘suspend’. The menu option worked just fine – it took about two seconds for my notebook to go into coma. It switched off, but not completely – the power LED indicated that the computer was using some, but not all of it. The problem was with waking up. No key or key combination it seems can wake up the computer, except for the power button. When the power button is pressed, the machine quickly awakes from it’s sleep, but that goes to shut down immediately. Ouch!
I’ve talked with some people on IRC, but noone could pinpoint the problem right away. All of them suggested that I surf the web for the solution. Some of them confirmed that they’ve got suspend working just fine, but that they had to fool around with configuration, source code, or even the kernel.
As I don’t have much use for neither hybernate, nor suspend, I won’t be searching for the solution now. Maybe later. If any of you though know how to fix it for sure, please, let me know via comments.