[ryao]

Unikernel proponents seem to assume that hardware virtualization will forever be the abstraction of cloud computing. However, hardware virtualization is the wrong abstraction, which is why the industry is beginning to adopt containers. There is no reason why you cannot run a unikernel in UNIX binary mode inside a container, but then it is really just a different way of developing a userland process rather than a unikernel. You definitely could still call it a unikernel. You would get the advantages of modularity that you specified and you would have all of the debuggability and observability that regular applications have today with the tools that we have today. However, that is rather different than the role in which they are intended to operate.

I guess my point is that the unikernel is always going to be the equivalent of a userland process. The question is whether your bare-metal kernel is going to be a traditional one or a hypervisor. They have definite performance advantages over a traditional kernel when your bare metal kernel is a hypervisor, but I believe that is the wrong abstraction when I consider overhead.