The tutorial provides the detailing on the Server Virtualization concepts in the cloud environment, types of server virtualization, advantages and usage of server virtualization
What is Server Virtualization ?
Virtualization means “Virtual” and not actual. Virtualization is the technology through which multiple simulated environments or dedicated resources are shared from a single physical hardware. Read what is Virtualization ? for more details.
Server Vitalization is the concept of utilizing the Physical Server resources more efficiently by dividing into multiple unique and isolated Virtual Servers. Without Server Virtualization, the physical server workload was not distributed to the full server capacity and thus servers were underutilized with respect to resources.
Server Virtualization allows each virtual server to act as physical server by running its own applications and operating system. This increases the overall performance for request processing, optimum utilization of resources and thus increasing the overall capacity of each physical server.
Types of Server Virtualization
The below given are the Server Virtualization Types:
1) Full-Virtualization: Full Virtualization is the type of Server Virtualization which uses HyperVisor which acts as the layer between the operating system and the hardware. The HyperVisor are classified into below 2 types:
- HyperVisor Type1 ( also known as bare metal or native hypervisor) which acts like a lightweight operating system and runs directly on the host’s hardware
- HyperVisor Type2 ( also known as hosted hypervisor) which runs as a software on top of the operating system
Full Vitalization technique uses hypervisor for communicating directly with the physical server and CPU. It manages and provide the resources to each virtual server and keeps their execution isolated by making them run independently with the usage of hypervisor. Examples of full virtualization are VMware and ESX Servers.
The Full Virtualization depends highly on hypervisor which has its own processing needs which could impact the overall server performance.
2) Para-Virtualization: While Full Virtualization provides each virtual server to run independently with impacting each other, the Para-Virtualization uses the entire network as a unit and thus each operating system in the virutal sever is aware about other existing virtual servers. This reduces the Hypervisor processing needs to manage the operating system and enhances the overall server performance. Examples of para virtualization is Xen.
3) OS-Level Virtualization: The OS level Virtualization also called system level virtualization does not use HyperVisor rather it is the physical server operating system which performs all tasks of Hypervisor and creates virtual servers using the same operating system.
Key Benefits of Server Virtualization
- Reduces the overall operating costs
- Provides high server availability
- Provides ease for managing virtual servers ( stop, restart services) without impacting other running virtual servers
- increases the overall application performance
- provides better disaster recovery support
Limitation of Server Virtualization
- The application hosted using virtual servers are tightly bounded. The failure of server virtualization will impact all those applications.
- Highly skilled manpower is required to setup the server virtualization
- Requires high cost as consumes high memory and hardware