- It is the process of dividing a physical server into several virtual servers. It’s called virtual private servers. Each one can run independently. In this Virtualization widely used in the IT infrastructure .
Types of Server Virtualization
- Hypervisor plays an important role in server virtualization. It is a layer between the hardware and operating system (OS).
- There are two types of hypervisors.
- Type 1 hypervisor (It is also known as Native Hypervisors or Bare metal)
- Type 2 hypervisor (It is also known as Embedded hypervisors or hosted)
- It is mainly used to perform several tasks like allocate physical hardware resources (CPU, RAM etc.,) to several smaller independent virtual machines, called "guest" on the host machine.
2. Full Virtualization
- It uses to directly communicate with the CPU and physical server. The best isolation and security mechanism to the virtual machines.
- It can slow down the application and server performance that is the main advantage.
- Example: VMWare ESX server.
3. Para Virtualization
- Like as Full Virtualization.
- Easier to use.
- Enhanced performance.
- Does not require emulation overhead.
4. Operating System Virtualization
- It’s also known as system-lever virtualization.
- It may be a server virtualization technology that separates one operating system into numerous isolated user-space called virtual environments. The greatest advantage of using server visualization is that it reduces the use of physical space, so it'll save money.
- Linux OS Virtualization
- Windows OS Virtualization
- FreeVPS, OpenVZ
- Linux Vserver
5. Hardware Assisted Virtualization
- Hardware Assisted Virtualization was presented by AMD and Intel.
- Hardware Assisted Virtualization is called as Hardware virtualization, AMD virtualization, and Intel virtualization.
- It is used to increase the performance of the processor.
6. Kernel-Level Virtualization
- Kernel-level virtualization is one of the important type of server virtualization. It is an open-source virtualization which uses the Linux kernal as a hypervisor. The advantage of utilizing kernal virtualization is that it does not require any administrative program and has very less overhead.
- User Mode Linux
- Kernel-based virtual machine
Advantages of Server Virtualization
- Independent Restart
- Low Cost
- Disaster Recovery
- Faster deployment of resources
Disadvantages of Server Virtualization
- When the server goes offline, all the websites that are hosted by the server. It will also go down.
- There is no way to measure the performance of virtualized environments.
- A huge amount of RAM consumption required..
- It is very difficult to set up.
- It is very difficult to maintain.
- Some applications and databases are not supported in this virtualization.
- To requires extra hardware resources.
Uses of Server Virtualization
- It is used in the testing and development environment.
- It improves availability of servers.
- It allows organizations to make efficient use of resources.
- It reduces redundancy.