How to install OpenStack on Xen

asked 2014-12-12 01:37:38 -0600

agm123 gravatar image

updated 2014-12-30 19:05:48 -0600

smaffulli gravatar image

I was trying to get OpenStack running in a virtual box using Xen hypervisor. Since Xen is hardware based virtualisation, I installed Xen in the host. After that, when I tried opening virtual box, it shows me some kernel erros.

I read virtual box cannot be run above xen hypervisor.

My objective is to install OpenStack using Xen. Can some one please tell me how to go forward?

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answered 2015-01-26 04:17:19 -0600

Bob Ball gravatar image

VirtualBox can emulate all of the hardware needed to run Xen within the virtual machine. You are correct that if you install Xen on the host itself then the VM inside VirtualBox will have no access to the hypervisor.

You need to install Xen within the VirtualBox machine. has some information on the settings that you'll need to successfully run Xen within VirtualBox, but note that you do not need to run XenServer, just set up the settings then you can use your choice of distribution to run Xen.

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answered 2014-12-12 01:58:52 -0600

dbaxps gravatar image

updated 2014-12-12 02:59:28 -0600

Regarding Xen as a tool for Openstack deployment ( like VMWare Workstation) :-
Xen is bare metal Hypervisor, so you can create Xen Paravirtual VMs (DomUs) , running Ubuntu 14.04
(or CentOS 7) to host Controller,Network,Compute Openstack nodes.

Domain 0, a modified Linux kernel, is a unique virtual machine running on the Xen
hypervisor that has special rights to access physical I/O resources as well as interact with
the other virtual machines (Domain U: PV and HVM Guests) running on the system. All
Xen virtualization environments require Domain 0 to be running before any other virtual
machines can be started.
Two drivers are included in Domain 0 to support network and local disk requests from
Domain U PV and HVM Guests (see below); the Network Backend Driver and the Block
Backend Driver. The Network Backend Driver communicates directly with the local
networking hardware to process all virtual machines requests coming from the Domain U
guests. The Block Backend Driver communicates with the local storage disk to read and
write data from the drive based upon Domain U requests.


Domain U
DomainU guests have no direct access to physical hardware on the machine as a
Domain0 Guest does and is often referred to as unprivileged. All paravirtualized virtual
machines running on a Xen hypervisor are referred to as
Domain U PV Guests
and are
modified Linux operating systems, Solaris, FreeBSD, and other UNIX operating systems.
All fully virtualized machines running on a Xen hypervisor are referred to as
Domain U
HVM Guests
and run standard Windows or any other unchanged operating system.
The Domain U PV Guest virtual machine is aware that it does not have direct access to
the hardware and recognizes that other virtual machines are running on the same
machine. The Domain U HVM Guest virtual machine is not aware that it is sharing
processing time on the hardware and that other virtual machines are present.
A Domain U PV Guest contains two drivers for network and disk access, PV Network
Driver and PV Block Driver

For further details view

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thanks a lot sir for your reply. I am following the legacy architecture which includes controller and compute node. Well, so what you say is all the nodes -controller and compute nodes should be run in domU?

agm123 gravatar imageagm123 ( 2014-12-12 02:06:42 -0600 )edit

Sir, as DomU doesn't have direct access to hardware, if compute node is configured in DomU , will it be able to access the xen which sits directly on the hardware below the OS.

Could you please clarify me this doubt?

agm123 gravatar imageagm123 ( 2014-12-12 07:44:50 -0600 )edit

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Asked: 2014-12-12 01:37:38 -0600

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Last updated: Jan 26 '15