IIRC the Debian installer assigns the swap space to be equal to the available RAM if automated partitioning is used but I always pre-partition so I might be wrong.

I can't find what the default is for the Devuan/Debian Installer, but you are right that the general recommendation is that you should have more swap than memory, and mostly the recommendation is x2.

This doesn't explain why yours has much less.

I've never used automatic partitioning, usually because I'm configuring something more complicated like LVM or RAID or have other live OS already on other partitions and don't want to lose them.

My mail sever has no swap (well it never hibernates and I'd rather it kill processes than try and use swap).

My desktop machine has lots of disks, from various generations of installs, most have swap partitions and I actually use a different partition for hibernation, which is x2 RAM, than the primary one, which is about 1.5 x RAM, that I use for swap as such.

kapqa wrote:

well, i have just let devuan installer do automatic partitioning, there must be an error then -
surely i have forgot to double check the partitioning process.

I doubt if the automatic configuration of the partitioning would have allowed for your wish to use swap for hibernation.

sorry, but i don't understand,
i was under the impression that the ratio on debian/ubuntu for automatic partitioning > swapfile size is around 1:1.5 (memorysize:swapfile) .. it should hence be around 4.5 GB with 3GB RAM.

well, i have just let devuan installer do automatic partitioning, there must be an error then -
surely i have forgot to double check the partitioning process.

I doubt if the automatic configuration of the partitioning would have allowed for your wish to use swap for hibernation.

root@devuan:~# free -h
              total        used        free      shared  buff/cache   available
Mem:          2.8Gi       491Mi       1.8Gi        85Mi       601Mi       2.1Gi
Swap:         255Mi          0B       255Mi

Whatever the other issues , this looks problematic for successful hibernation since the Mem in use (491Mi), which is what needs to be written to disk on hibernation, is nearly twice as large as Swap you have (255Mi, all free).
Usually you would want to have as much swap as memory.

when evoked with root it gives

 echo disk > /sys/power/state
-bash: echo: write error: No such device

cat /sys/power/state /proc/swaps
free -h

You did run my suggested command from a root prompt, right?

i am also having problems with hibernate on lenovo t400 and devuan beowulf. if remember correctly it functioned on ascii.

suspend works (although not when closing laptop lid, but when evoked manually through dedicated keyboard combination or when typing "sudo pm-suspend").

hibernation however, fails.

sudo hibernate

does not go full hibernation (does not count the per-cents of progress) and from black screen resumes to active state with message

hibernate:Warning: Tuxonice binary signature file not found.

sudo pm-hibernate

also seems to go hibernation mode, but then resumes to normal with no terminal output whatsoever.

EDIT: tried also other suggestion

 echo disk > /sys/power/state
-bash: echo: write error: No space left on device

man loginctl

...or...

loginctl --help

I kind of vaguely remember trying to install the uswsusp/uspsusp package but not being able to find it for the Droid4... this seems to be connected to a hibernation-module in the kernel, right? or is it just about the devices repositories?

I don't know anything about compiling kernels (yet!), but, if I do learn, will it be possible to compile it for that device with the "hibernation-module/functionality" activated? or is it another module? another technique?

how can I get hibernation? i love hibernation

You can achieve hibernation either through kernel mode, which requires the appropriate kernel module, or in userspace, using uswsusp or tuxonice.

If your device https://leste.maemo.org/Motorola_Droid_4 lacks both kernel support (available kernels don't have the appropriate kernel module) and you don't have the package uswsusp in your sources then I think that means that you would have to compile one or the other to get hibernation (though even then it could be possible that your hardware lacks the appropriate hooks to make it work).

NB. Just as an update on my earlier posts I do now have hibernate running using kernel mode on Beowulf on my (pretty ordinary) AMD64 hardware, though I also still use pm-hibernate to call it as I have a few things I want to invoke in the pre-sleep and post-wake scripts.

You also need to have a resume=UUID=your.swap.drive.UUID (or similar) command in the linux vmlinux line in your grub menuentry. This tells the kernel where to store/restore your memory image.