hibernation support - lack of distro-wide coordination between systemd, dracut, anaconda, pm-utils and maybe more?

[Chris Murphy]

On Tue, Apr 14, 2015 at 3:07 AM, Bastien Nocera <bnocera at redhat.com> wrote:
>
>
> ----- Original Message -----
>> OK not everyone is on the same page, apparently. This bug was just
>> closed by Anaconda as WONTFIX.
>>
>> suggested swap for laptop seems low
>> https://bugzilla.redhat.com/show_bug.cgi?id=1037472
>>
>> I don't see how hibernation works reliably with such a low default swap size.
>
> This isn't the way to fix it. The hibernation file/partition should really be independent
> of swap, because 1) you can't be sure how much swap will actually be used by the applications
> so you can't be sure you'll ever have enough swap to save the RAM 2) Too much swap and the
> (lack of) interactivity will make you want to advocate physical violence when your machine
> is unusable for an hour because of a hungry Javascript in your 50th Firefox tab.

Windows and OS X both use swapfiles rather than swap partition, and a
sleep image file rather than a partition. OS X's swapfiles are
dynamically created on demand in variable size increments.

Recently, Windows on UEFI systems with the proper hardware uses Intel
Rapid Start [1], which is firmware managed suspend-to-disk. It depends
on both a unique partition and SSD, and by default a shutdown uses
this. Cold boots are really fast, like ~1.5 seconds. Faster than
reboots.

Both OS's have a feature that I find invaluable on a laptop which is
the automatic switch from suspend-to-RAM to suspend-to-disk. Because
of this, I never do shutdowns. I can always rely on just closing the
laptop lid to get suspend-to-RAM and if necessary (time or low
battery) the system wakes and suspends-to-disk. I can't rely on
suspend-to-RAM on linux because I can't guarantee I'll remember to
wake it and do a proper shutdown before the battery dies.

I'd put suspend-to-disk in the same category as video problems. It's
yet another reason to just not fight things, give up, and use what
works which is either Windows or OS X, and put Linux in a VM. *shrug*


> I requested a hibernation partition that wasn't a swap partition:
> https://wiki.gnome.org/BastienNocera/KernelWishlist
> but it was deemed unnecessary by kernel devs (or work-aroundable maybe):
> http://thread.gmane.org/gmane.linux.kernel/1810083/focus=1813873
>
> We need to fix the kernel first, then we can ask for support in Anaconda.

If kernel developers don't see working suspend-to-disk to be
important, then in my view Linux on the desktop is just short of
pointless and is just treading water with the existing behavior. The
two other OS's simply do this way way better and more reliably to the
point it's bulletproof and completely trustworthy.

How is this working on Chromebooks?

[1] http://mjg59.dreamwidth.org/26022.html


-- 
Chris Murphy