Re: Status of hibernation (suspend to disk) in Guix

[Mekeor Melire]

2022-12-09 23:10 mekeor@posteo.de:

> 2022-12-05 17:23 ivan@selidor.net:
>
> > in #59746 I skipped documenting `resume_offset` with more detail, even
> > if it's needed for resuming from a swap file. The reason is that
> > according to [swsusp doc][1], some specific tool may be needed to
> > compute the swap file offset. There is [swap-offset][2] from the
> > uswsusp suite, which is missing from Guix and no longer shipped with
> > Debian.
>
> What about the "filefrag" executable from the "e2fsprogs" package.
> According to this article, it can be used in place of the deprecated
> uswsusp suite:
>
> https://www.linuxuprising.com/2021/08/how-to-enable-hibernation-on-ubuntu.html

I just tried this out. And it worked like a charm! I have hibernated and
resumed successfully - first time with Guix System. I'm so happy :)

Would you like to add instructions for swap-files to your
patch-series #59746?

What I did: First, determine offset:

--8<---------------cut here---------------start------------->8---
$ sudo filefrag -v /swapfile
Filesystem type is: ef53
File size of /swapfile is 1717986918 (4194304 blocks of 4096 bytes)
 ext:     logical_offset:        physical_offset: length:   expected: flags:
   0:        0..       0:    5308416..   5308416:      1:
--8<---------------cut here---------------end--------------->8---

Then, use offset in operating-system declaration:

--8<---------------cut here---------------start------------->8---
  (kernel-arguments
    (cons*
      "resume=/dev/mapper/cryptroot"
      "resume_offset=5308416"
      %default-kernel-arguments))
--8<---------------cut here---------------end--------------->8---

Caveat: IIUC, this does not work with Btrfs.