[spartango]

Your explanation is clever and could account for most of the behavior of the product. Certainly the environments, rapid booting, and even hot resizing.

What's missing, however, is how they do machine state snapshots (not supported in any container system afaik). I know Xen/VMWare support these, but if they are running atop AWS they will not have access to the hypervisor. I can imagine kludgily running another hypervisor atop AWS, but there would appear to be a more clever solution.

[Swannie]

As far as I am aware, OpenVZ has had running container backups for over 2 years now:

https://openvz.org/Backup_of_a_running_container_with_vzdump

And it uses copy on write for even faster snap-shotting and consistency.

[wmf]

Check out CRIU.

[spartango]

Cool, thanks. I hadn't seen this before.

For those wondering: CRIU is Checkpoint/Restore In Userspace.

http://criu.org/Main_Page is the project, and http://criu.org/LXC is container support.

From a quick look, it seems that there are some limitations in CRIU, especially with LXC support, but it is work in the right direction.