nyrna VS criu

Someone pointed me in the direction of "Nyrna", which looks promising! https://nyrna.merritt.codes/ (Can download a free trial from the MS Store)

please try https://github.com/Merrit/nyrna and let me know how well it works.

It currently only works on X11 but Nyrna seems like it's made for this use case

Nyrna - Used for suspending the active application with a hotkey

If on PC, recommend using Nyrna : https://nyrna.merritt.codes/ . You can set the hotkey to the Pause/Break button on your keyboard, and it will force the current application (eg Hogwarts Legacy) to pause midcutscene and show the desktop till hit the hotkey again.

Here's an application for Windows: https://github.com/Merrit/nyrna

- Download the application "Nyrna" from https://nyrna.merritt.codes/. Download page located in the top right, select the version for your operating system (for this guide, I am using Windows 10)

But there is maybe a way to solve this problem. While looking for a solution i stumbled over the programm Nyrna which allows to suspend programs. You could in theory freeze the game at one point and send your computer in stand-by / hibernation and continue the next day. But i have not experimented much with it.

There is a 3rd party program, Nyrna. It lets you pause any game at any point, keep it in RAM without using up any other resources, then get back to it whenever you want to.

Checkpoint/Restore I feel is a bigger concept than just saving state. At the zeroth level it's a system that can correctly stop and serialize a running process (as criu https://github.com/checkpoint-restore/criu has shown is a huge pain in the ass to still not be perfect) in a way that can initiated from within the process itself.

The 1st level more-work-but-easier way to do this is to build or use a heavily constrained VM/language you run from within your main application that doesn't allow for most of the hard problems to even exist.

I can't find any ready-made tools to do this that I wouldn't consider an endeavor.

That being said the Checkpoint Restore In Userspace project has been around for a number of years and is the closest thing to what you are talking about: taking a linux process on one machine and moving it to another. It is messy but can be done in some cases. There are folks looking at how to integrate CRIU with k8s but it’s all research at this point.

I would love to make more use of CRIU. E.g. I considered to use CRIU for my Python preloaded logic (https://github.com/albertz/python-preloaded). Unfortunately, at that point in time, CRIU must be used with root access, which was not an option. However, I see that the PR was merged now, so maybe it works now? (https://github.com/checkpoint-restore/criu/pull/1930)

There is also DMTCP (https://github.com/dmtcp/dmtcp/) but this might have other problems for my use case.

My solution was to use a fork server instead, which works almost equally well. There are not really much downsides with this approach. And this is actually quite simple, and also quite cross-platform (except Windows).

CRIU currently needs root access for dump/restore. However, there is ongoing work to support a non-root option in https://github.com/checkpoint-restore/criu/pull/1930.

There have been multiple checkpointing attempts over the years. Criu is the only one I know of that's still kicking. That's probably your best and only bet.