Hyper-V has dynamic memory, so memory resources can be reallocated as needed, and has driver hooks so that linux vms can be resized too. There's also Intel's cl

Hyper-V has dynamic memory, so memory resources can be reallocated as needed, and has driver hooks so that linux vms can be resized too. There's also Intel's clear containers push which virtualizes for linux but shares a lot of kernel structures between the host and the VM.