We clone a running VM in 2 seconds (2022)

The VM vs container debate is fascinating. They are separate yet slowly merging concepts that are becoming more blurred as technology becomes cheaper and faster. If the real bottleneck to scale is adaptable code, then it is foolish to dismiss the VM as outdated tech when it can be completely rehomed in 2 seconds. That megabyte of python code managing your containers would still be busy checking it's dependencies in that same timeframe.

In a way it's nothing new. MOSIX/openMosix (https://en.wikipedia.org/wiki/MOSIX, https://en.wikipedia.org/wiki/OpenMosix) did similar stuff with individual processes. It would probably be even faster as then you would have to only move process memory and its state rather than the whole VM memory (and it state).

I guess it would/could be nice to have something that moves kubernetes pods around rather killing them and starting new ones.

IMHO the real advancement was the implicit snapshot Docker takes after every line in a Dockerfile.

Virtual Machine builder scripts like Packer could do this… but don’t.

It’s a choice, not an inherent technology limitation.

I have the opposite opinion, the implicit overlay filesystem in Docker is an unnecessary and frustrating complication.