RHEL 4 & Hibernate

[ed at eh3.com (Ed Hill)]

On Sun, 2005-05-01 at 07:08 -0500, Anthony Gabrielson wrote:
> Hello,
> 	I'm running CentOS 4, an RHEL 4 clone, on a Dell Latitude D810 M70 
> laptop and I'm looking for a few pointers on hibernation.


Hi Anthony,

You have at least three "suspend" or "hibernate" options: APM, ACPI, and
swsusp2.  APM is the "old way" and it doesn't work on many new laptops.
Plus the APM kernel bits conflict with ACPI which is needed for many
things (eg. CPU throttling) so they can't be loaded together at the same
time.  ACPI is the "new way".  It addition to a lot of other BIOS-type
stuff, it supports various suspend modes and it may or may not work on
your hardware.  Finally, there is a cool new swsusp2 project that allows
for suspend-to-disk functionality (a complete power-down with zero
battery drain over time) that works without any specialized hardware
support and is completely independent of APM and ACPI.

If you want to try APM or ACPI (ACPI S3 is "suspend-to-RAM") then your
best bet is to look for other peoples' notes concerning your laptop
model.  Start with http://linux-laptop.net/ and then try Google-ing for
your laptop model name and the above terms.

And if you'd like to try the new swsusp2 bits, the easiest way is to get
(S)RPMs from:

  http://mhensler.de/swsusp/

and follow the directions on that site.

Both ACPI S3 and swsusp2 are working very reliably on my ThinkPad A22p.
I've used ACPI S3 and, more recently, swsusp2 on a daily basis (at least
2X/day and often many more) and both have worked nicely.  I put some
notes at:

  http://eh3.com/thinkpad_T42p.html

Ed

-- 
Edward H. Hill III, PhD
office:  MIT Dept. of EAPS;  Rm 54-1424;  77 Massachusetts Ave.
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