A virtual machine is a complete computer, called a guest, that works within another computer, called the host. A virtual machine uses software to emulate the hardware of a computer and taps into the hardware of the host to create a new computer environment. In that virtual computer, you can install another operating system that is completely isolated from the host.
- [Voiceover] Virtual machines allow a single computer to run multiple operating systems at the same time. These operating systems can vary and be different than the one that is natively installed on the machine. With virtual machines, there is the host and the guest. The host is the physical computer or operating system that is installed on your computer. For example, you might have a MacBook Pro with OS X installed, or you could have a Surface Pro with Windows 10. Each of these are examples of a host computer. A host computer has a number of physical components.
These are components that exist in the real world. For example, your processor, memory, and storage space on your computer are physical components of your host system. You only have so many processors with a specific number of cores, so much memory, and storage space on your hard drive. A guest computer is one that exists virtually. Guest computers exist only within the VMware software. VMware uses software referred to as a hypervisor that allows physical hardware to connect to virtual hardware in one or more multiple guest operating systems.
There are two generic types of hypervisors. The first, sometimes called a Type-1, Native or Bare-Metal hypervisor, worked directly on top of the hardware without an operating system in-between. One or many operating systems in virtual machines are installed on top of the hypervisor. The second, called a Type-2 or Hosted hypervisor, is software-based and runs on top of a natively installed operating system. This hypervisor can then have multiple guests that have virtual hardware that is supported by the physical host.
And the type that VMware Fusion uses in Fusion 8 is a Type-2 or Hosted hypervisor. VMware also makes a Type-1 or Native hypervisor called ESX, or ESXi. When you create a virtual machine using VMware, you'll need to define the amount of virtual hardware for your guest machine. The amount of virtual hardware will define how much of the physical hardware needs to be reserved for the virtual machine to work. So for instance, if I have a machine with an A core processor, I could create a virtual machine that will need two cores.
My machine could have eight gigabytes of RAM, and I could define the VM to have four. Or my guest could use 32 gigabytes of hard drive space where my host might have available 256. When you reserve resources from your physical hardware though, your native applications that run alongside VMware won't have as many resources available because VMware is reserving them for the guest's use. But VMware is smart, and if a guest isn't using a resource, it can make it available for the native host. But if the guest needs it, those resources are immediately assigned back to the guest, which could cause a reduction in performance of host applications, including the operating system itself.
When you create a virtual machine, you are creating an empty shell. You have the virtual hardware. And VMware creates a virtual BIOS system that allows the virtual machine to boot. But without an operating system installed, the guest won't do anything. Installing the operating system is something that you need to do to fully create the virtual machine.
- Installing VMware Fusion 8
- Setting up virtual machines
- Setting up a custom virtual machine
- Setting up file sharing
- Managing virtual snapshots