Hi Nolan,

Nolan Wright <nolan.wright.other@gmail.com> writes:

> I have a desktop computer that sits in the same room where I
> sleep. The fans produce a noise that I would prefer not to hear when
> going to bed. For that reason, I wish to make use of the hibernation
> feature, in which the system state is suspended to disk as described
> here:
>
> https://wiki.archlinux.org/index.php/Power_management/Suspend_and_hibernate
>
> The IRC user nxck, who was very helpful, after some brief
> experimentation concluded that Guix System probably does not support
> the hibernation feature. Indeed the following comment in the source
> code suggests as much:
>
> http://git.savannah.gnu.org/cgit/guix.git/tree/gnu/services/desktop.scm#n598
>
> Additionally I found the following message in this mailing list from
> three years ago which stated that the feature is not supported:
>
> https://lists.gnu.org/archive/html/bug-guix/2016-11/msg00067.html

The message above links to an earlier message with my preliminary patch
to support hibernation:

  https://lists.gnu.org/archive/html/guix-devel/2016-08/msg00962.html

I've been carrying that patch in my local branch of Guix for 3 years.
It needs a bit more work before it's ready to include in Guix, and I'm
sorry to say that I lost motivation to work on it because it seems that
almost no one cares about hibernation today.

Anyway, I've attached below a slightly updated version of the patch that
applies cleanly to current Guix.  Quoting from the message above:

you'll also need to add a line like this to your 'operating-system'
definition.

  (kernel-arguments '("resume=/dev/sda2"))

Where the device named is a swap partition.

WARNING: Since this is preliminary work, I recommend that the first time
you test this, be prepared for the possibility that resume will fail.
So far I've only tested it with simple partitions, without encryption or
RAID.

It may be that we should add a dedicated 'resume-device' field to the
'operating-system'.  Thoughts?

      Mark