High-priority final exam comparison. Source: Cloud Lec 3.
| Dimension | Type 1 (Bare-Metal) | Type 2 (Hosted) |
|---|---|---|
| Also called | Bare-metal hypervisor | Hosted hypervisor |
| Install layer | Directly on hardware (acts as host OS) | On top of a host OS (Windows, Linux, etc.) |
| Speed | Faster — no host OS overhead | Slower — host OS consumes hardware resources |
| Reliability | Production-grade; used in datacenters | Not reliable for large datacenters |
| Primary use | Enterprise servers, cloud infrastructure | Testing, development, education |
| Examples | VMware ESXi, Microsoft Hyper-V, KVM | VMware Workstation, Oracle VirtualBox, Client Hyper-V |
| VM management | Hypervisor allocates resources per VM config | Application on host OS creates isolated VMs |
The host operating system runs on the physical machine and takes CPU, memory, and I/O before the hypervisor and guest VMs receive resources. Type 1 installs directly on hardware, eliminating that overhead.
A hypervisor is the software layer that performs virtualization — it sits between hardware and virtual machines, allocating resources to each VM. Type 1 (bare-metal) hypervisors install directly on hardware (ESXi, Hyper-V, KVM). They are faster and used in production datacenters because no host OS consumes resources. Type 2 (hosted) hypervisors run as applications on a host OS (Workstation, VirtualBox, Client Hyper-V). Type 2 is slower because the host OS takes CPU, memory, and I/O first. Type 1 suits enterprise server consolidation; Type 2 suits testing, development, and education. Choose Type 1 for production scale; Type 2 for personal dev environments.
Primary source: Dr. Sherif Mostafa, Cloud Lec 3 — Hypervisor (Type 1 & 2).