Commonly used virtualization technologies are these: Microsoft's Hyper-V, KVM in Linux, XEN, VMware's ESXI, Docker.
1. Hyper-V
Hyper-V is a virtualization product of Microsoft. It is Microsoft's first hypervisor-based technology similar to VMware ESXi and Citrix Xen. It is a system management program virtualization technology proposed by Microsoft that can be implemented. Desktop virtualization. From Windows Server 2008, Microsoft's server system version can be installed on the server manager.
2. KVM
KVM virtualization is called kernel-based Virtual Machine. It is an open source system virtualization module. Kernel-based virtual machine (KVM) is for x86 hardware that includes virtualization extensions (Intel VT or AMD-V). Linux's completely native virtualization solution. At present, KVM has been acquired by redhat, and it has become a function expansion of the virtual machine in the Linux kernel.
There is also a virtualization technology in Linux, Qemu, and KVM complement each other, called Qemu-kvm, which supplements the deficiencies of kvm technology and optimizes kvm in performance.
What is Libvirt? It is a series of library functions provided to be used by other technologies to manage virtual machines on the machine. Including various virtual machine technologies, kvm, xen, lxc, etc. Different virtual machine technologies can use different drivers, and all can call the API provided by libvirt to manage the virtual machine. The various virtual machines we create are managed based on the libvirt library and related commands.
Expansion: Virtualization technology is divided into three types of virtualization in terms of technical realization:
fully virtualized technology: the
reallocation of operating system resources through software is relatively mature, and fully virtualized representative technologies: KVM, ESXI, Hyper-V.
Paravirtualization technology:
Modify existing systems through code to form a new virtualizable system, call hardware resources to install multiple systems, the overall speed is relatively higher, paravirtualization represents technology: Xen.
Lightweight virtualization:
Between full virtualization and paravirtualization, lightweight virtualization represents technology: Docker.
3. ESXI
VMware ESXI virtualization features are as follows:
ensuring business continuity and always available IT;
reducing IT hardware and operating costs;
improving application quality;
enhancing security and data protection capabilities.
4. XEN
XEN is an open source virtualization technology based on the X86 architecture, with the fastest development, the most stable performance, and the least resource consumption. Xen can safely execute multiple virtual machines on a set of physical hardware, and Linux is a perfect open source combination. It is particularly suitable for server application integration, which can effectively save operating costs, improve equipment utilization, and maximize the use of IT infrastructure in data centers.
Fifth, Docker
Docker is a lightweight, high-performance virtualization technology, is currently the most used virtualization technology on the Internet, the essence of Docker virtualization technology is similar to the container mechanism, when the earliest container did not appear, there were many handling on the dock After the container appeared, more workers were not on the dock, and the handling mode of the container was more single and more efficient.
Packing the goods in the container more can prevent the goods from affecting each other. And if you need to transfer to another wharf, you can ship it directly to another wharf after you have the container, which can completely ensure that the goods inside are relocated as a whole and will not damage the goods themselves.
Docker virtualization is an open source application container engine that allows developers to package their applications and dependent packages into a portable container and then publish it to any popular Linux machine. It can also be virtualized.
Docker containers use the sandbox mechanism completely, there is no interface between each other, there is almost no performance overhead, and they can be easily run in machines and data centers. Most importantly, they do not depend on any language, framework or include system.
Docker virtualization technology is based on hardware, based on the existing operating system level to achieve virtualization, directly reuse the operating system of the local host, directly generate Docker containers, and deploy related APP applications (Apache, MYSQL, PHP, JAVA).
Sixth,
KVM, XEN, ESXI traditional virtualization (complete, paravirtualization) is based on the hardware, based on the existing operating system level to achieve virtualization, but can not reuse the operating system of the local host, but must Virtualize your own Guest OS system, and then deploy related APP applications (Apache, MYSQL, PHP, JAVA) on the Guest OS system.
Compared with traditional VM, Docker virtualization has the following advantages: The
operation starts quickly:
the performance at runtime can be greatly improved, and the management operations (start, stop, start, restart, etc.) are all in seconds or milliseconds.
Lightweight virtualization: You will have enough "operating system", just add or reduce images. 100 to 1000 Containers can be deployed on one server. But with traditional virtualization, it is good if you virtualize 10-20 virtual machines. Open source, free and low cost.