What is Virtualization?
Suppose there is a number of applications to be performed to run your business and eventually it will require the same number of servers i.e. one server for one application. This is the simplest strategy one can consider while designing IT infrastructure, but it will be costliest that is it will increase the operating cost of business also It will not utilize available recourses properly.
The solution to this problem is virtualization. If you are the guy from the technology industry then you must have been heard about multiplexing. It’s simply nothing but sharing single communication media between multiple users. You can apply the same analogy to virtualization, here physical hardware is shared among the various operating system or applications and gives them a look of an independent entity.
What is Virtualization – Explained
The main component which separates the single physical hardware among various virtual machines is called a hypervisor.it is a type of operating system and software, which operates on physical hardware. It dynamically allocates available physical resources to virtual machines to be created.
What are the benefits of using Virtualization?
There are multiple advantages of a virtualization, out of which important ones are
- Infrastructure cost reduced to a great extent
- Energy efficient
- Enhance the productivity of the system
- Enable remote login
What are types of Virtualization?
The concept of Virtualization can be further extended to Server, Application, Memory, Storage and networking virtualization.
1. Server Virtualization
The most common type which generally considered virtualization is server virtualization. It is nothing but running multiple operating systems on a single physical hardware and most important is they are running independently. As the resources are shared among different OS the proper utilization of resources takes place. Each separate O.S. is also pronounced as guests, instances, or containers.
2. Desktop Virtualization
In this type of virtualization, multiple user desktop instances are created on a single host. Users are having the facility to access these desktop instances remotely. The best example of desktop virtualization is N-computing.
3. Application Virtualization
Here the application to be virtualized is installed on a host and can be used by multiple number of users remotely. The WINE is the example of software which is used for application virtualization. It allows UNIX based operating systems to run Microsoft Windows based software directly on host. With the help of application virtualization, the application data is synchronized with main server and can available anytime to the user.
4. Application Virtualization
It is nothing but pool of different physical storage units. It is managed by a software generally by hypervisor. it provides scalability, redundancy, improved performance. Due to storage virtualization the problem of limited storage can be resolved because one can add memory quickly into a pool. The storage virtualization can be further classified as
5. Network Virtualization
It combines number of physical networks into a virtual single network or vice-versa. This new virtual network is software managed network.
The best example of network virtualization is to create virtual LAN. It is logical to a group of computers. They are appearing to be on the same LAN but they are virtually created. The advantage of network virtualization is that the network admin can automate the networking task and no need to control it manually. Also, it is very easy to scale the network according to requirements. Some of the advantages of network virtualization are
- It reduces the cost of hardware purchase
- Faster application delivery
- Improved security
- Centralized control
- Scalable network
What is Hypervisor? What are the types of Hypervisor?
It is software that is responsible to create and control virtual machines. Currently, there is a number of hypervisors which are available in the market, some of the famous examples are, Oracle Virtual Box (Apple, Linux, Microsoft), Microsoft Virtual PC 2007 (Microsoft), Parallels (Apple), Microsoft Hyper–V (Microsoft), VMware (Apple, Linux, Microsoft), Citrix (Apple, Linux, Microsoft), Linux VServer (Linux).
What are the types of Hypervisor?
Hypervisors are mainly categorized according to their placement into the system. Generally, there are two types of hypervisors are there which are
Type 1 (native) hypervisor:
In this type of hypervisor, then it is installed directly onto hardware without being managed by the operating system into the middle. They are also known as bare-metal types of hypervisors. As it is having direct access to the hardware is faster than the next type of hypervisor that we will be going to discuss soon. It’s more secure and scalable too.
VMware ESX and ESXi, Microsoft Hyper-V, Citrix XenServer, Oracle VM are some examples of type 1 hypervisor.
Type 2 (hosted) hypervisor:
here the hypervisor is not installed directly onto hardware rather there is an operating system between hardware and hypervisor which controls the hypervisor. it uses the O.S. virtualization technique. As the operating system controls the hypervisor that’s why it is somewhat slower than type1 hypervisors. Scalability is also somewhat limited as compared with the previous type. It is less secure too.
VMware Workstation/Fusion/Player, VMware Server, Microsoft Virtual PC are some examples of type 1 hypervisor.
KVM As a Hypervisor
Kernel-based Virtual Machine is the Linux-based type-1 hypervisor. It supports native virtualization on the processor. Technically speaking it’s not a perfect type 1 neither type2, it’s somewhat middle between them. some of the key benefits are consist of loadable kernel modules.
- It is very secure due to SELinux and sVirt library.
- Gives near-native performance.
- KVM is also full virtualization technology thus no modification is required into the guest operating system.
- It also supports memory virtualization capabilities therefore all types of memory access mechanisms are supported
- Most of all It is open source and thus free to use