[systemd-devel] [PATCHv6 0/3] hibernate-resume: implement support for resuming from hibernation

[Jan Janssen]

Ivan Shapovalov <intelfx100 <at> gmail.com> writes:

> 
> On Wednesday 27 August 2014 at 03:16:10, Zbigniew Jędrzejewski-Szmek wrote:	
> > On Tue, Aug 26, 2014 at 10:21:59PM +0200, Lennart Poettering wrote:
> > > On Wed, 27.08.14 00:17, Ivan Shapovalov (intelfx100 <at> gmail.com) wrote:
> > > > This patchset allows systemd to parse resume= kernel command line
parameter
> > > > and initiate resume from the specified device.
> > What about swap files with the resume_offset= parameter? Are they still
> > being used?
> 
> I don't know if somebody uses that, but for now it's missing functionality.
> 
> After a cursory search, I could not find a mechanism to initiate a resume with
> offset from userspace. In Arch, it was never implemented even if possible.
> 

I'm a heavy user of this myself. It's especially useful because you can just
have a single luks encrypted ext4 without a lvm in between for a swap
partition or (even more yuck) using a separate (encrypted) swap partition.

Arch does support this, mostly because as far as I know, the resume_offset=
is consumed by the kernel, while resume= has to refer to the (unencrypted)
filesystem (/dev/mapper/root in my case). So, as long as this solution waits
for the device to show up in /dev/ (and especially /dev/mapper/ for my
case), this should work out.

Here's information to set this up. Imho more people should be aware this is
possible:
https://wiki.archlinux.org/index.php/Suspend#Hibernation_into_swap_file

Jan