a. KVM overview :
Kernel-based Virtual Machine (KVM) is a hardware-assisted,
fully virtualization solution for Linux® on
x86 and x86_64 hardware that contains virtualization extensions –
specifically Intel® VT or AMD-V.
After you install KVM-related software, you can run multiple guests
(virtual machines), with each one running a different operating system
image. Each of these virtual machines is assigned private, virtualized
hardware.
Using KVM, one can run multiple virtual machines running unmodified
Linux or Windows images. Each virtual machine has private virtualized
hardware: a network card, disk, graphics adapter, etc.
The kernel component of KVM is included in mainline Linux, as of 2.6.20.
KVM is open source software.
1. Cost. KVM is totally free. and it's also have same function as proprietary virtual server like VMware
2. Ease of Deployment. Installing KVM as easy as running apt-get on Ubuntu or Debian. KVM offer no licenses.
3. Speed. It is more responsive that other virtual server
4. Management. KVM can be managed over command line, or via graphical interfaces
