What the Heck Is a Unikernel? And Why Should You Care?

Just when the tech world was starting to get their heads around containers, along come unikernels. Like containers, unikernels have been around in some form or another for quite awhile. Their resurgence has to do in large part to their container-like functionality. In a nutshell, unikernels combine an uber-stripped down version of an OS packaged with an individual app or service, providing a unit even smaller and more agile than a container.

Back in January, Docker, seeing the strategic importance (threat?) of unikernels, acquired Unikernel Systems. Unikernel Systems, based in Cambridge in the UK, is made up of former developers of the Xen hypervisor project.

At OSCON, I caught up with Richard Mortier — formally of Unikernel systems and now a Docker employee — to learn about the wild and wacky world of unikernels.

Some of the Ground Richard Covers

• What is a unikernel?
• How is Docker positioning unikernels within its portfolio?
• Mirage System and unikernel construction.
• How unikernels augment, rather than replace containers.

Unikernels: Love 'Em? Hate 'Em?

Unikernels are not without their vehement detractors.  Roman Shaposhnik, in his post "In Defense of Unikernels," does a pretty good job of laying out the good and the bad.  Roman's conclusion:

….unikernels are not a panacea. Nothing is. But they are a very useful building block that doesn't need any additional FUD. If you really want to fight something that is way overhyped you know where to find Linux containers.

Extra-Credit Reading

• Introducing Unik: Build and Run Unikernels with Ease – Linux.com
• Docker bags unikernel gurus – now you can be just like Linus Torvalds – The Register
• "Unikernels will send us back to the DOS era" – DTrace guru Bryan Cantrill speaks out – The Register
• Docker kicks off the unikernel revolution – InfoWorld

Pau for now…