Hibernation / Suspend to Disk
 

Hi,
does or will Maemo support hibernation (suspend to disk),
which Linux supports on most PCs?

It is a very useful feature if you want keep all your applications
open and in the same state over periods of power off.

There are several scenarios in which you want or have to turn off the device but don't want to start all applications again:

* over night: saves energy and let's you sleep
* in the proximity of sensitive devices (clinic)
* battery changing

cheers

Re: Hibernation / Supsend to Disk
 

Turning the device doesn't save power unless you're talking in terms of days.

Shutting down and restarting is probably faster than hibernating, honestly.

Re: Hibernation / Supsend to Disk
 

after recharging the battery in the evening
I see no point in keeping the device on during my sleep.
I don't mean saving battery power but energy in general.

I know some people are used to keeping all devices on (TV)
even if they leave their house but some people are more environmentally aware.

speed is not an issue here. I just don't to restore all applications and their states (e.g. open terminals, website position) whenever I power it on again. And think we cannot realistically expect all applications to support proper session management.

Re: Hibernation / Supsend to Disk
 

Though, I'd like hibernation very much. At least to change battery when the first one is dead.
Could be an interesting project when my N900 is available; maybe tough too.

Re: Hibernation / Supsend to Disk
 

Saving battery means saving energy in general...

AFAIK, booting the device up consumes so much power that you're doing better by keeping the device in offline mode over night.

Re: Hibernation / Supsend to Disk
 

Ah, yes, this is a productive way to have a discussion.

Yes, this is the case.

Re: Hibernation / Supsend to Disk
 

Well, there had been some work on suspending to RAM during the Chinook/early-Diablo era. I don't know of anyone working on anything similar for Maemo 5 though.

Suspension to RAM/disk would probably be best as a Brainstorm idea at this point.

Re: Hibernation / Supsend to Disk
 

This is wrong for the 770/N800/N810, and even more wrong for the N900 with its (supposedly) better processor and power hungry radios.
See here for a simple calculation:
http://talk.maemo.org/showthread.php...639#post297639

The advantage of hibernation is not only in the very little time it might save, but in the fact that you get your computer in the same state as you left it - same programs open with the same documents in the same locations, etc.

Re: Hibernation / Supsend to Disk
 

Video playback does not use the same amount of power as bootup. Either way, I'm more inclined to trust the kernel engineers at Nokia who live and breath this stuff than some random estimates on a web forum. :)

Re: Hibernation / Supsend to Disk
 

Well, if they tell you that 1+1=3 and you trust them, good for you.

Please ask them what is the system current draw at idle, and during shutdown./boot. Then do the math.