When comparing Mirage OS vs OSv, the Slant community recommends Mirage OS for most people. In the question“What are the best unikernels?” Mirage OS is ranked 2nd while OSv is ranked 3rd. The most important reason people chose Mirage OS is:
There are more than 100 libraries compatible with MirageOS available and more are being developed everyday.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Large collection of libraries available
There are more than 100 libraries compatible with MirageOS available and more are being developed everyday.
Pro Built with security in mind
What MirageOS does in simple terms is to provide only the minimal needed for an app to run. It provides only the required network and hardware drivers needed to execute.
Using this approach it minimizes the attack surface for potential hackers since they don't have any shell to log into or any other insecure cruft that other deployment methods, such as full operating systems have.
Pro OCaml
Pro Quick booting
OSv is able to boot in less than a second.
Pro Amazing performance
Since OSv is created to run one single application on top of a hypervisor, it offers great performance and speed.
Pro Supports multiple platforms
OSv can run applications written in multiple programming languages and that run on multiple different platforms. Such as Java, C, Ruby, Node and Scala. With support for other languages on the way.
Cons
Con May be too much for regular development work
Letting developers work closer to the metal also makes them lose a lot of the useful abstractions a normal OS has which are not built for no reason. Considering this, it may not be a good idea to always use MirageOS for deploying an application.
Con Can only run one application at a time
Since it tries to have maximum performance, OSv can only afford to run one application per hypervisor at a time.