Where is Xen Hypervisor installed? [closed]

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Closed 9 years ago.

Will it be installed on existing OS or hardware?

What's the difference between Hypervisor and virtualbox? I know I can install virtualbox on my windows xp and then install a couple of VMS with linux or windows on it.

thanks.

Answer 1

Where is Xen Hypervisor installed? Will it be installed on existing OS or hardware?

As explained in the fine wikipedia article, Xen is a bare-metal hypervisor, meaning it runs directly on the hardware.

However, as Xen itself has no user interface, it always requires at least one installed guest OS to work. There must be one OS guest that runs with special privileges (the so-called "dom0"). This dom0 is used to manage Xen, and so has a similar role to the host OS on a hosted hypervisor. So, while technically speaking Xen runs directly on your hardware, in practice you will still install an OS, then install Xen from inside the OS, just like for a hosted solution. However, you will then have to reboot into Xen (which will boot the dom0 OS).

What's the difference between Hypervisor and virtualbox?

Hypervisor is the general term, and both Xen and VirtualBox are implementations of hypervisors.

I know I can install virtualbox on my windows xp and then install a couple of VMS with linux or windows on it.

Yes, you can do the same with Xen (though support for Windows guests seems to be more limited than with VirtualBox).

Answer 2

Full virtualisation is difficult to achieve (e.g.: virtualbox) and is slow, because you should create an exact copy of the underlying hardware, and difficult to recover from hardware errors.

Paravirtualisation (xen hypervisor) provides the machine hardware, but sitll manages it. And Operating System, that will be installed as VM should have some modifications.

Xen still needs some OS to manage resources of the VMs, so it will not be installed on hardware only. Citrix Zen Server for example uses CentOS5 (which is quite outdated, by the way).

The paravirtualisation approach is good for Cloud computing because of the ability to effectively run multiple VMs on a number of different machines and scale.

I suggest you to read an article called "Above the Clouds".