I discovered this when I read about ClickOS [0], a unikernel that builds on the Click modular router. Check this out: "ClickOS virtual machines are small (5MB), boot quickly (about 30 milliseconds), add little delay (45 microseconds) and over one hundred of them can be concurrently run while saturating a 10Gb pipe on a commodity server"

[0] https://www.usenix.org/system/files/conference/nsdi14/nsdi14...