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I was thinking about virtualisation and how to explain it to a non-technical person and one of the things that I was wondering was how to explain the way that a VM is isolated and seperate from the phyiscal machine (so I can have a virus on a VM but this would never effect my physical host, right?).

How does this technology work exactly? As I am a programmer, when I think of isolating processes, I think of using appdomains (I work with C# primarily).


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It's not isolated from the physical host, it's isolated from the logical host.

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What is the difference? – dotnetdev Mar 21 '10 at 1:38
The "logical host" is what makes the "physical host" a unique entity on a network domain. It's basically a combo of physical hardware+OS+configuration. So the VM is a unique logical host that consists of virtual HW+OS+config. However, the VM can't be separated from it's physical host, or it would cease to exist, since the VM exists on top of a hypervisor, which runs on the physical hardware of the host. – Joe Internet Mar 21 '10 at 3:45

Everything (well pretty much everything) you do in a virtual machine is basically emulated (or passed through).

It doesn't matter what you run within the Virtual Machine, your physical machine will only see a single application running - the VM software/Hypervisor/Similar itself.

However, a Virtual Machine - especially in Bridged networking mode runs identically as any physical machine on the network, this means, if it gets infected with any sort of malware such as Zombie/Spam/DDOS, it will still do the same job and if you get any virus that can infect other machines over the network, it could infect your machine.

(This question is similar to this, You may want to read to learn a little more, however, I think this is different enough not to be a duplicate)

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Yes, not to mention the blue – Joe Internet Mar 21 '10 at 3:48

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