Gigaom’s Jonathan Vanian interviews Docker’s CEO Ben Golub and posts on June 27, 2014. I had a chance to talk to Jonathan before he interviewed Ben and I had a simple question. If you have a 100 servers running workloads that would fit in a Dockers environment how much better is Dockers vs. a typical virtualized environment? Here is what Jonathan wrote up.
How can Docker be smaller than a VM? Microsoft in its support for Docker writes an explanation.
By making Docker containers significantly smaller than traditional VMs, they can be booted/restarted more quickly, more of them can run on a single host and they are considerably more portable. Furthermore, when capturing a new Docker container, the tooling only needs to capture the differences between the original and the new container. This makes it possible to rationalize Docker as a kind of version control system for disk images.
One simple assumption you can make is if something is lighter with its size there is a 1-1 relationship between being lighter means you should be able to be more efficient. If you are 20% lighter, than you can do 25% more work with the same capacity. If you are at the extreme of 80% lighter, then you can do 500% more work with the same capacity of server hardware.
As time goes on we’ll hopefully see real world results of how much more efficient Docker is than a hypervisor virtualization strategy.
Disclosure: I work for Gigaom Research as a part-time freelance analyst.