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

[Jim Kinney]

try setting the system to hibernate when battery is low. Hibernate uses the
same power as system-off, i.e. none. Suspend is save to ram which will
croak when the power does fail.

To hibernate, you need swap = ram + used swap at the point of hibernate.

On Sat, Nov 5, 2011 at 6:48 PM, Ron Frazier
<atllinuxenthinfo at c3energy.com>wrote:

> Hi all,
>
> I've verified experimentally that Ubuntu 10.04 will not let the machine
> hibernate if there is no swap space.  This seems to confirm what I read
> elsewhere that the swap space is used for the hibernation data.
> (Windows uses a separate file.)  I believe that you must have a swap
> space equal to and perhaps a bit larger than RAM in order to hibernate.
> I prefer not to use standby or suspend since, at least in terms of
> Windows in the past, that has been known to cause data corruption since
> the standby data is in RAM and could be lost if the battery is weak,
> etc.  As I write this, I'm noticing that my laptop offers a suspend
> option in Linux and the desktop does not.  In any case, if I don't want
> to do a full shutdown, I prefer to have all the system state data saved
> to the disk and all the power shut down.
>
> I'd be interested to know whether setting the power settings to shutdown
> or hibernate is better in case the UPS battery gets critically low after
> a power failure.  In my case, the UPS only runs 3-4 minutes on the
> desktop, so I currently have that setting on shutdown.  I figured the
> system can shut down faster than it can hibernate.  If anyone knows, I'd
> also like to know how to set the shutdown time on the Gnome power
> manager.  If, for example, the system shuts down when the UPS is at 10%
> after a power failure, this is bad for me since that amounts to about 18
> seconds of warning before the battery dies.  I don't think even Linux
> can shut down that fast.
>
> Sincerely,
>
> Ron
>
> --
>
> (PS - If you email me and don't get a quick response, you might want to
> call on the phone.  I get about 300 emails per day from alternate energy
> mailing lists and such.  I don't always see new messages very quickly.)
>
> Ron Frazier
>
> 770-205-9422 (O)   Leave a message.
> linuxdude AT c3energy.com
>
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-- 
-- 
James P. Kinney III

As long as the general population is passive, apathetic, diverted to
consumerism or hatred of the vulnerable, then the powerful can do as they
please, and those who survive will be left to contemplate the outcome.
- *2011 Noam Chomsky

http://heretothereideas.blogspot.com/
*
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