openstack team mailing list archive

["Dugger, Donald D" <donald.d.dugger@xxxxxxxxx>]

I don't claim to be an expert on OpenStack on OpenStack but I don't believe you need VTx at all.  IPMI, yes you need that, but not VTx.

The idea behind OS on OS is that you are installing an image onto the bare metal host, you are not utilizing the VTx features nor are you using KVM.  You need something like IPMI so that you can kick start the bare metal host but the whole idea is that there is nothing on the host to begin with so KVM support is not an issue.  Once you've kick started the host to run the OpenStack code then, since the normal OpenStack code is running, you can use KVM (if the host supports VTx or SVM) or `qemu' (on any x86 machine) to run instances..

As a side note, nested virtualization (the ability to run a hypervisor inside a virtualized guest) is something that we at Intel are interested in and working on but there are no distributions that officially support this feature in a production environment - yet.

--
Don Dugger
"Censeo Toto nos in Kansa esse decisse." - D. Gale
Ph: 303/443-3786

From: Openstack [mailto:openstack-bounces+donald.d.dugger=intel.com@xxxxxxxxxxxxxxxxxxx] On Behalf Of Chris Bartels
Sent: Tuesday, April 30, 2013 2:12 PM
To: openstack@xxxxxxxxxxxxxxxxxxx
Subject: [Openstack] OpenStack in OpenStack Without a 'VT-x' CPU

Hi,

I've currently got my laptop & all its accessories for sale on eBay in hopes of selling it so that I can raise money with which to purchase a cheap, used server for the purpose of installing OpenStack on OpenStack. This so that I can tinker with it & get my head wrapped around utilizing OpenStack in a HA clustered configuration with Landscape & Juju in the new Ubuntu.

It appears that the server I had hoped to be able to buy, which had the kind of Xeon processor which featured VT-x extensions, will likely be sold out by the time my laptop sells, and this leaves me with some other, less desirable servers available to me in my price range, some of which feature the older kind of Xeon processor which do not feature the VT-x virtualization technology.

I don't know if I should consider these as servers I might want to purchase for my purposes- they could be a great value if they'll work with a nested OpenStack setup.

It has been my experience, at least with ProxmoxVE, which is a KVM-based bare-metal hypervisor distro, that when I would run ProxmoxVE nested inside a ProxmoxVE, I wouldn't have KVM available to use in the nested OS, since the required VT-x virtualization extensions were only available to the OS that was installed to the bare metal, & not to the nested OS. They didn't forward to the nested OS.

My question to you, is whether I'll be able to run KVM in a nested OpenStack inside OpenStack when the VT-x is only available to the OpenStack that's installed to the bare metal.

So, if the nested OpenStack doesn't need the VT-x to be forwarded to it by the OpenStack that's installed to the bare metal, then does the OpenStack that's installed to the bare metal require the VT-x extensions at all either? Could I run KVM in both bare metal & nested tiers without VT-x being present at all?

These wouldn't be production servers, so I don't care much about speed, although I wouldn't be buying any whose CPU was less than 3.3GHz, so should they be running fully emulated, I wouldn't mind the performance hit, because their purpose is simply to allow me to familiarize myself with using OpenStack in various configurations before I go & install it in a production environment on high quality servers- in a year or 2 from now.



tl;dr-

1.       Does the nested KVM running inside the OpenStack that runs inside another OpenStack get to take advantage of the VT-x of the host CPU?

2.       Does OpenStack on OpenStack running KVM in each need VT-x on the host CPU at all to run properly?

Please advise.


Thanks in advance.


Kindest Regards,
Chris Bartels