Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 08-05-2008 Installation Manual page 537

28.5.2 Configuring APM and ACPI
Suspend and Standby
There are three basic ACPI sleep modes and two APM sleep modes:
Suspend to Disk (ACPI S4, APM suspend)
Saves the entire memory content to the hard disk. The computer is switched off
completely and does not consume any power. This sleep mode is enabled by default
and should work on all systems.
Suspend to RAM (ACPI S3, APM suspend)
Saves the states of all devices to the main memory. Only the main memory continues
consuming power. SUSE Linux Enterprise does not generally support this sleep
mode although you can use it for quite a number of machines.
This sleep mode is enabled by default, but it is only executed if the current machine
is listed in a database as capable of supporting this mode. This database is contained
in the /usr/sbin/s2ram binary provided by the suspend package.
To modify the default parameters (for example, to generally disable the suspend
to ram sleep mode or to force it even for machines not listed in the database),
find more information about available options in the /etc/sysconfig/
powersave/sleep configuration file.
To learn more about the s2ram binary, refer to the README files in /usr/
share/doc/packages/suspend.
Standby (ACPI S1, APM standby)
Switches some devices off (manufacturer-dependent).
Make sure that the following default options are set in the file /etc/sysconfig/
powersave/events for the correct processing of suspend, standby, and resume
(default settings following the installation of SUSE Linux Enterprise):
EVENT_GLOBAL_SUSPEND2DISK=
"prepare_suspend_to_disk screen_saver do_suspend_to_disk"
EVENT_GLOBAL_SUSPEND2RAM=
"prepare_suspend_to_ram screen_saver do_suspend_to_ram"
EVENT_GLOBAL_STANDBY=
"prepare_standby screen_saver do_standby"
Power Management 519