How AWS EC2 Virtualization Model Influences Performance
Choosing the right AWS EC2 Virtualization model is becoming increasingly important as part of selecting the right instance type for your workloads. As a quick recap, an AWS EC2 instance is a virtual machine on top of bare metal with a hypervisor in between.
So which EC2 Virtualization model should you use? And how does it affect your instance type selection?
Para Virtualization (PV)
Circa 2014, Software-defined virtualization or Para Virtualization was all the rage. It was lightweight, offered benefits over other virtualization models ( like HVM). However, given that there is a software layer over bare metal, some compute capacity was spent for managing the virtualization layer as well. Also, the guest OS needs some modification before it can be Para Virtualized. The modifications are essentially replacing instructions that can’t be run natively with a HYPERCALL. ( Read more about Xen and PV at the XenProject.org and virtualization spectrum in particular Understanding the Virtualization Spectrum )