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Re: cannot hibernate Dell Latitude D600



Hi Alex,

There are 3 different suspend-to-disk (hibernate) implementations out
there.

swsusp is part of mainline 2.6 kernel, but is not turned on in the
default set of compile options and has apparently caused the Debian
maintainers sufficient problems that they are now disabling it.

pmdisk is a fork of swsusp and also in mainline 2.6 kernel but in the
process of being merged back into swsusp and is similarly not compiled
into the debian kernels

swsusp2 also known as suspend2 and software-suspend2 is a new
implementation that currently requires patching and recompiling your
kernel. The deb file you installed from their site only contains the
script to actually trigger the hibernation and not the kernel patches to
make it happen. The maintainers of suspend2 hope to get it into the
mainline kernel Real Soon Now, but they've been saying that for over a
year. Their patches are massive against the current kernel and have
raised some objections from the kernel gurus. The patches are being
broken down into smaller useful-on-their-own chunks and some are
starting to be incorporated into the kernel and the stability of swsusp2
is improving. But don't necessarily expect it all to make it into the
mainline kernel any time soon.

All 3 implementations have problems... if the work for you then stick to
them and don't change anything... if they don't work for you at the
moment, then they probably never will.

swsusp2 is probably the most likely to work as it doesn't require ACPI
control to work, but it is also probably the least tested at this stage
and has many experimental features still. Support for initrd is only
just starting to be incorporated and there are still many discussions on
the devel mailing list about trashed ext3 or xfs etc partitions. Your
data is not necessarily safe with swsusp2.

swsusp and pmdisk do not support highmem (> 830-ish MB RAM) and also
have bugs, some of which can't be fixed as they are a fundamental
limitation of the current kernel and driver model. The swsusp2 team is
trying to get around these limitations, but that requires many invasive
changes to the kernel.

I have never managed to get any of these to work on my laptop (1GB
RAM)... swsusp2 is approaching the stability I require, so I might have
another go at it in a few months' time and see if I can get it working
this time.

Regarding the "Hibernate" etc buttons in KDE, these only work if your
system is already configured to do something intelligent with them: e.g.
the hibernate button is just a graphical way of triggering whatever
hibernate function you have working for you (e.g. swsusp2). The sleep
mode relies on ACPI sleep working, which it does on a small fraction of
laptops, but unfortunately not mine either (HP/Compaq are not being very
linux friendly!)

Good luck!

Stuart

-- 
Stuart Prescott                 www.nanoNANOnano.net






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