What is virtualization
I.e. virtualization technology Virtualization, virtualization technology refers to a virtual machine for multiple logical computers. A plurality of logical computers running simultaneously on a single computer, computer executable logic for each different Caozuoxitong, and the application can run independently of each other without affecting each other in a space, thereby significantly improving the working efficiency of a computer.
Virtualization software to use the method to redefine the division of IT resources, enables dynamic allocation of IT resources, flexible scheduling, cross-domain sharing, improve IT resource utilization and enable IT resources to truly become a social infrastructure and services in all walks of life flexible changing application requirements.
In actual production, virtualization technology is mainly used to solve the physical hardware performance overcapacity and low capacity old hardware recombinant reuse, transparent underlying physical hardware, to maximize the use of physical hardware
There are many types of virtualization technology, such as software virtualization and hardware virtualization, memory virtualization, network virtualization, desktop virtualization, service virtualization, virtual machines
Virtualization architecture
Full virtualization
Guest operating system places no restrictions host operating system, the virtual machine is fully virtualized, need to simulate the entire machine, including hardware, each virtual machine requires its own operating system, once the virtual machine is turned on, the pre-assigned to it resources will all be occupied. Each virtual machine includes application, the necessary binaries and libraries, as well as a complete user operating system.
Operating system level virtualization
The client operating system and must be consistent with the host operating system, vessel technology is a way to achieve operating system virtualization, allowing you to isolate the process by running the application resources and their dependencies. And sharing the host kernel container, without the need for analog hardware
Platform virtualization (hardware virtualization)
No need to install the host operating system, the guest operating system can be installed free to the company after the purchase of servers often run using virtualization platform to simulate multiple servers
Hypervisor
Hypervisor is an intermediate software layer between the operating physical servers and operating systems, operating systems and allows multiple applications to share a set of underlying physical hardware, and therefore may be regarded as the virtual environment "meta" operating system, he coordinate all the physical devices and virtual machines to access the server, also known as a virtual machine monitor. Hypervisor virtualization technology is the core of all. When the server is up and execute Hypervisor, he will give each virtual machine is allocated the right amount of memory, CPU, network and disk, and load the guest operating system all virtual machines. Common products Vmware, KVM, Xen and so on.
