Suspend to RAM

[Ernie McCracken]

On Wed, Dec 15, 2004 at 11:15:38AM -1000, Amy M wrote:
> Looks like you may be the Savior.  Any info that will help me do the 
> suspend to RAM in FC3 will be greatly appreciated.
> 
> I have an HP ze4560 notebook.  The only way I was able to cause it to 
> hibernate (suspend to RAM) was to issue a command:
> 
> echo 4 > /proc/acpi/sleep

I think that ACPI state 4 is for "suspend to disk" (i.e., hibernation).
I think you want state 3, which is suspend to RAM (i.e., standby).

See here:  http://acpi.sourceforge.net/documentation/sleep.html

> 
> But as everyone would have guessed, with this command (and nothing 
> else), I would not able to wake the machine up after I put it into 
> hibernation.

I put this in a shell script that runs when I close the lid of my
laptop.

In /etc/acpi/events/sample.conf, I put this:

event=button/lid.*
action=/usr/local/t40suspend.sh


The contents of t40suspend.sh are as follows:

echo -n "mem" > /sys/power/state && hwclock --hctosys


echo -n "mem" > /sys/power/state is the equivalent of echo 3 >
/proc/api/sleep

hwclock --hctosys sets the system time from the hardware clock.