What are the mainstream virtualization technologies Explain the five mainstream virtualization techn

openvz，xen，kvm

At present, there are three common virtualization technologies: 1. OpenVZ, an operating system-level virtualization technology, which is more flexible to configure; 2. Xen is a semi-virtualization technology, which can freely load kernel modules, virtual memory and IO; 3. KVM, completely virtual, supports any type of operating system.

OpenVZ advantages: The service provider licenses the memory and CPU very well. Disadvantages: Since it is based on the operating system, you will use it less if others use it more. After the memory is down, it is very unstable.

Xen advantages: memory exclusive, although small but all allocated. No matter how low the memory is, it will not be down, and it will not respond for a period of time. Disadvantages: small memory, small hard disk, small bandwidth. PV performance is better.

Advantages of KVM: Completely virtual, regardless of the difference between PV and HVM. Supports any type of operating system.

Learn what virtualization is in two minutes.

Advantages: It can save the purchase cost, electricity cost, and space of the physical server. It is also easy to manage and can achieve high availability (for example, when a physical host goes down, VMs running on that host are automatically migrated to another host).

The benefits that virtualization can offer depend on the customer's goals, the particular virtualization technology chosen, and the existing IT infrastructure. Not all customers will be able to reap the same benefits from implementing a particular virtualization solution. Now, even with simple server consolidation using virtualization, customers can often reap a lot of benefits in some way:

Higher resource utilization—Virtualization enables the dynamic sharing of physical resources and resource pools, improving resource utilization, especially for different workloads whose average demand is much lower than the need to provide dedicated resources.

nReduced management costs – Virtual can improve staff efficiency by: reducing the amount of physical resources that must be managed; Hide part of the complexity of physical resources; Streamlining public administration tasks by automating, gaining access to better information, and enabling management; Automate load management. In addition, virtual debates can support the use of public tools on multiple platforms.

nImprove flexibility – Virtualization enables dynamic resource deployment and reconfiguration to meet changing business needs.

nImproved security – Virtualization enables isolation and partitioning that cannot be achieved by simpler sharing mechanisms, and these features enable controllable and secure access to data and services.

nHigher availability – Virtual resources can be deleted, upgraded, or changed without affecting users.

Higher scalability – Depending on the product, resource partitioning and aggregation can support virtual resources that are much smaller or larger than individual physical resources, which means you can scale without changing the allocation of physical resources.

Interoperability and investment protection – Virtual resources provide compatibility with a wide range of interfaces and protocols that the underlying physical resources cannot provide.

nImproved Resources** – Virtual is able to allocate resources in smaller units than individual physical resource units.

Background to the emergence of technology:

As enterprises grow, businesses and applications continue to increase, IT systems become increasingly large, energy consumption is high, and data center space is tight.

High costs, wasteful resources, underutilized resources, and inflexible infrastructure.

Advantages of virtualization technology:

Improve hardware utilization.

Reduce energy consumption and save energy.

Improve IT O&M efficiency and reduce system management personnel.

Decoupling of operating system and hardware.

Classification of the nature of work.

Operating system virtualization.

Application virtualization.

Desktop application virtualization.

Storage virtualization.

Network virtualization.