Create RW disk snapshots of running Firecracker microVMs

[s3rj1k]

A way to do disk snapshoting on a runnig VM

[ad-m]

Let's do that. It's just file.

[raduweiss]

I assume you're thinking of snapshots while the guest is still running? Asking since if you stop the guest / microVM the file representing the microVMs file system that stays behind is effectively a snapshot.

[s3rj1k]

@raduweiss yes, while VM is running

[acatangiu]

What's the usecase for this?

Please always bear in mind that Firecracker is designed for short-lived specialized tasks and not a general-purpose VM.

[s3rj1k]

being able to make point in time backup is always a good thing

[raduweiss]

@s3rj1k , I thought about this for a bit, and indeed a proper backup image can't be achieved without changes in Firecracker. This is something we've also talked about in the team, and we're going to continue looking at. I'll leave the issue open so we have it on our radar (we're going to organize ourselves with some milestones in the near future).

[s3rj1k]

@raduweiss cool, sounds great :)

[raduweiss]

@s3rj1k, @ad-m, we've added something like this to the roadmap, see #1184. Figuring out exactly how this will work (e.g., if/how you rw disk snapshots) will probably be discussed as part of that issue.

[acatangiu]

@s3rj1k we've released dev-preview snapshotting functionality in v0.23 with full support coming up in v0.24.

Does that cover this issue?

[s3rj1k]

@acatangiu Yea, that's great news, thanks!
https://github.com/firecracker-microvm/firecracker/blob/v0.23.0/docs/snapshotting/snapshot-support.md