Introduction to Virtualization

                      Virtualization is the act of making virtual version of something like server, desktop, storage or network. It make use of the existing actual hardware to be distributed among different operating system or applications.

                                If we virtualize our servers we can save lot of power by using single physical server for different roles as virtual machines in that physical server. Another advantage is the hardware consolidation. The number of hardware devices need to be take care of will be minimized using virtualization. Also virtualization makes the system recovery easy, as the virtual machine resides as a single file in the host machine. You can copy the virtual machines and thus it makes it easy to setup similar server roles through duplication.

                                   The thing which manages and runs the virtual machine is called as a hypervisor. There are two types of hypervisors, type1 and type2. Type1 or bare metal hypervisor boots up as a virtualization OS. VMware ESXi is an example for that.Type2 or host based hypervisor runs as an application inside the host operating system. Microsoft Hyper-V or VMware workstation are examples of that. VMware, Microsoft and Citrix are the major vendors providing hypervisors. Microsoft Hyper-V comes with windows 7 onwards as an installable option. Oracle gives a completely free hypervisor called VirtualBox.

        Let us create a virtual machine using VMware workstation.

1.   Click on create new virtual machine.

2.   Choose typical and Click Next.

You can choose the source of installation files here. I am choosing my downloaded redhat Linux iso image.

3.   Click Next and provide the username and password.

4.   Click Next and name your os and choose the location where you want to store the VM.

5.   Click Next and enter the hard disk space required for the VM. Even though I gave 20GB it will not use the entire space in the physical disk right now. It will use the disk space on demand up to 20GB. This is called thin provisioning.

6.   Click Finish and check the box power on virtual machine after creation.

You can click customize hardware to change the memory, virtual switch, processor etc.

When the virtual machine power on, it will start the installation of Redhat Linux.