[ale] Linux swap space vs hibernate, power shutdown settings

[Ron Frazier]

David,

I've done some testing and gotten some, shall we say, interesting results.

The specs for my machine are: AMD Phenom II X4 quad core CPU, 8 GB RAM, 
Ubuntu 10.04.

I booted a live CD of Ubuntu 11.04 (different from my installed system 
but power drain about the same) and pulled the plug on the AC input to 
the UPS. Everything was at the default settings for the CD, and no 
applications were running. The drain on the battery was 247 W.

The good news is that the battery lasted 9 min 45 sec, a bit longer than 
I thought it would. The bad news is that the battery charge went from 
about 30% to about 0%, according to Ubuntu, in just a few seconds. The 
machine shut down very abruptly, and I don't think it had time to do a 
shutdown sequence. That's why I was booting from a CD. I'm probably 
going to use the gconf-editor to set the shutdown point at 70% of full 
charge in my normal system.

I timed a shutdown sequence with my email and Firefox running. There 
were 5 FF windows and they had 7, 2, 6, 6, 6 tabs open respectively. A 
16 GB swap file was available but none was in use prior to shutdown 
according to System Monitor. There were no unsaved files open which 
might delay a shutdown by asking questions about saving them. (What 
would happen if they were open?)

The shutdown sequence took 9 seconds to complete, very impressive.

I then tried to do a hibernate. That didn't turn out so well. The system 
spent 30 seconds trying to hibernate, produced some error messages on 
the text screen, then restarted and went back to the login screen on the 
screen saver after about 1 minute. So, it never hibernated at all. For 
now, I have it set to shut down on low battery. I still need to tinker 
with the levels where it shuts down though, as it's probably defaulting 
to 10% charge.

I posted a picture of the error screen which I took with my cellphone. 
If anyone knows what this means, please let me know. It's posted here:

http://dl.dropbox.com/u/9879631/hibernate%20error.jpg

Sincerely,

Ron


On 11/05/2011 09:43 PM, David Tomaschik wrote:
> Time how long your system takes to shut down and how long it takes to
> hibernate.  Make sure you do both with the same apps loaded, etc.  I'd
> be interested to see any hard data.
>
> David
>    

-- 

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Ron Frazier

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