DRAFT – Virtual Machines (VMs) and Hypervisors… What the heck are they?


VMs and Hypervisors are pretend machines



So what can I do with a VM?

Basically a VM is not YOUR machine it is a “fake” machine. Run something like Belarc Advisor (on Windows) and xxx (if on a Mac) and you will see what kind of CPU it is pretending to be. As a result it has no access to the hardware of your machine.

The fake machine does not have a fake set of PCI cards mirroring your own, for example. It can access your CD or DVD or Floppy drive only if you give it permission to via preferences and even then it creates a “fake” device it accesses it does not access your hardware directly. In fact even if you have fancy super fast caching disk controllers, etc. the VM does not have that. It has some fake/pretend simple disk controller. Since the software that starts and stops and runs the VM does I/O IT benefits from your fast disk access, but the VW it creates has a lesser controller/disk.

How can a VM Make me safer?



I am a programmer, why do I need a VM?




What is a HyperVisor?

For you to be able to have the VM be “Your machine” and see your hardware. That is called Type 1 / native / bare metal / hypervisor. VMware ESX/ESXi and Microsoft Hyper-V 2008/2012 for example. These are typically only possible with a Hypervisor installed.

The tools that create and manage one or many multiple machines is also called a Hypervisor. It is typically used and paid for when people need Type 1 VMs to get max speed from hardware and direct HW access. Because of the complexity of letting multiple fake machines see the real machine all the time and mitigating the traffic jams or concurrency issues Hypervisors like that don’t run on every piece of hardware out there, just specific machines they know they can support in “bare metal” mode.


Why Choose on VM over another?






What a VM cannot do



More Details on VMs and HyperVisors

Most people are running a Type 2 / hosted VM that is fake so cannot see underlying hardware. VMware Workstation, Oracle VBox and Virtual PC for example.

hope all these link help you GROK VMs.

Install your First VM Today – so you can try a different OS

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