Ohh!! Then, may be you don’t know what is Virtualization…..
Virtualization gives you the opportunity to install multiple operating systems in one Computer, you can utilize same Hard disk, RAM, CPU, you just have to allocate required resources to multiple instances. When I was doing RedHat Linux Certification, I formatted my Computer and installed Fresh Linux on it, then realized that I can use multiple Operating Systems on one computer by configuring Dual Boot System. Now I keep only one Primary Operating System and using VMware Workstation I create Virtual Machines in it. I can create N number of Virtual Machines with different operating systems on it.
Virtualization features :
– Reduce Your Cost
– Reduce Number of Servers
– Reduce Power / electricity usage
– Reduce Cooling equipment usage
– Simplify Administration and Maintenance
– Fast deployment
– Easy to Backup
– Reduce Server / Rack / Infrastructure Space
– Easy Migrations
– Increase the space utilization efficiency
– Deploy multiple operating system technologies on a single hardware platform
How Virtualization works ?
Virtualization can be implemented in 2 ways :
1) Software Virtualization:
As the name suggests, Software Virtualization allows us to install virtualization technology application onto your operating System and then you can manage Virtual machines from that Applications. In Software Virtualization the Operating System Cheats the Virtualization Application, when you create virtual instance / container / Virtual Machine and allocate some resource to it. The OS states that it allocated those resources to the Application i.e to the Virtual machine. As it shares many of the resources of the host OS so it virtual machines can be created almost instantly. You can also manage the resource changes easily like memory, CPU or hard Drive allocation. As resources are shared, a single software based Virtual Machine can often corrupt the host system or utilize all of the hosts resources, causing other Virtual Servers to fail. These are common issues with software Virtualization, though providers found some solutions or tricks to manage such issues but at the end the concept will be same. Hard disk I/O read-write issues are very common, if virtual machine owner is utilizing CPU or memory intensive applications on it then it causes issues. As this virtualization applications works on Host node so system updates / OS updates on the virtual machines are not possible until the host is upgraded. So drawbacks are, No Control Over VM OS updates, Shared resources like CPU, Ram, hard disk, Less Stable etc.
Known Software Virtualization applications are : Parallels Virtuozzo, Microsoft Virtual Server & Virtual PC, Citrix, VirtualBOX etc
2) Hardware Virtualization:
Here, we don’t need any operating system on main Hardware Node. The hardware virtualization technology providers provide us the Embedded Setup / Installer of the Hypervisor. Because each Virtual Sever has it’s own operating system, different operating systems can run on the same hardware node. Each hardware based Virtual Server can install their own updates, and have virtually no limitations for any configuration.Dedicated Memory and CPU resources gets allotted to the virtual machine, so no conflict with another VM which increases the setup cost for Hardware Virtualization.
Hardware Virtualization examples : VMware ESX / ESXi, Microsoft Hyper-V, Xen Server etc.
What are the types of Virtualization?
1) Server Virtualization:
As the name describes, this virtualization method allows us to share the resources of a server (hardware node) and create virtual machines by allocating them required resources. We can then install operating systems, applications on those Virtual machines. System Administrators uses Software or hardware virtualization method to divide one physical server into multiple isolated virtual environments.
2) Network Virtualization:
This virtualization type completely reproduces the Physical Network in Software, with the same features and guarantees of physical network, also gets the operational benefits and hardware independence of the virtualization. The benefits are rapid provisioning, non-disruptive deployment, automated maintenance, security, flexibility and support for both legacy and new applications and support for both legacy and new applications. All the services will be logical such as, logical ports, switches, routers etc to all connected workloads.
3) Desktop Virtualization:
You don’t have to give separate PC for each and every employee, just purchase few high configuration servers and share those hardware resources by creating remote instances which will be accessed remotely. Desktop virtualization is a technology used to separate a computer desktop environment from the physical computer, it uses client-server type of concept because the virtualized desktop is stored on a centralized, or remote server and not the physical machine being virtualized. VMware View is one of the known desktop virtualization example.
4) Application Virtualization:
Let me explain this in a different way. When we purchase database, word, excel, flash, ERP, multi-media application licenses for separate workstations then simply we are wasting those licenses. Citrix allows us to share the applications on multiple remote instances, if client need to access only Winamp player then why to give them the access of other applications? we can install all required applications on one high configuration server (it can be remote) and create separate (multiple) instances for each application then by installing terminal services lienses, we can allow N number of people to access one application. This is what the Application Virtualization is ! Once they are virtualized then they can utilize virtualization benefits like High Availability, disaster recovery, 100% uptime, agility, speed etc.
5) Storage Virtualization: