Basic knowledge of KVM kernel level virtual machines

The difference between KVM and VBox

VBox is rewritten by QEMU and contains a large amount of QEMU code.

Can be used for CPUs that do not support "http://www.aliyun.com/zixun/aggregation/13883.html" > virtualization technology.
It is worth saying that the vbox is better in graphics, can be 2D 3D acceleration.
But CPU control is not ideal (presumably because of graphics support).
The operation has an independent graphical interface, easy to get started.
KVM is what the Linux kernel contains, using QEMU as the upper management (command line).

Requires the CPU to support virtualization.
Performance: As a server is very good, but the graphics ability is very poor. Even if the film, the image is like paint, a layer of layers.
CPU usage control is good.
The control is relatively concise, the function is richer: for example, use "Invincible function" all changes to the memory, your mirror will always keep clean. The parent mirror feature lets you have n separate snapshot points. There are a lot of parameters. In addition, KVM as a kernel-level virtual machine, the initial development of the focus of the company more-but has not reached the level of commercial applications.
Overall: In the case of virtualization, the performance of VBox and KVM is about the same, mostly object-oriented: KVM is used on the server and VBox is used for desktop applications.

About KVM

KVM is open source software, full name is kernel-based virtual machine (kernel-level VM).
A Linux [Full virtualization] solution that is x86 architecture and that hardware supports virtualization technologies such as Intel VT or AMD-V.
It contains a core module Kvm.ko (Kvm-intel.ko or Kvm-amd.ko) that can be loaded for the processor to provide low-level virtualization.
KVM also requires a modified QEMU software (QEMU-KVM) as a virtual machine upper control and interface.
KVM can run multiple virtual machines at the same time without changing Linux or Windows mirroring (PS: It means that multiple virtual machines use the same image) and configure a personalized hardware environment for each virtual machine (NIC, disk, graphics adapter ...). ）。
The core of the mainstream Linux kernel, such as 2.6.20, contains the KVM cores.

Basic knowledge

QEMU is a stand-alone virtual software that can run virtual machines independently (no KVM is required). Kqemu is the software accelerator. KVM does not require QEMU for virtual processing, but requires its upper management interface for virtual machine control. The virtual machine is still powered by a KVM. So, let's not mistake the concept and blindly install QEMU and Kqemu.

Installation Preparation

See if your hardware supports virtualization. Command：

Egrep ' (VMX|SVM) '/proc/cpuinfo

To have VMX or SVM identification. In general, AMD is doing a better job of virtualization. Friends with Intel CPUs also need to go into the BIOS to set up-because I am AMD, so the set method is not to utter.

Installing KVM

Open the newly-established software library and install the KVM. The system automatically installs the associated packages, including QEMU-KVM. What KVM-AMD or Kvm-intel mode systems are automatically processed. Note: Past articles have mentioned that you need to set up kernel mode.