[PKG-Openstack-devel] Hypervisor for Openstack?

Turbo Fredriksson turbo at bayour.com
Mon May 30 11:05:32 UTC 2016

On May 30, 2016, at 10:07 AM, Thomas Goirand wrote:

> On 05/28/2016 08:37 PM, Turbo Fredriksson wrote:
>> So could someone please share some insight on how I can/should solve
>> the issue of having the possibility to run both Containers and "real
>> VMs", preferably on the same host, managed by nova-compute.
> This is not supported upstream. A single nova-compute can only manage
> one type of instance (ie: bare-metal, Qemu, KVM, etc.).

Dang! That's a surprise!!

Is there a reason why? Starting a VM is (should be) just "a simple API
call".. ?

> Also, LXC is kind of very badly supported right now in OpenStack

It turns out, that's perfectly ok! I've been using Docker at work
for the last couple of months, so I have some experience with that.

Since I couldn't find any references to it in any support matrix,
I started learning LXC yesterday.

It turns out it sucks! Dang, it took me twenty command lines to
do the same thing I did in ONE in Docker. AND it required me to
hack around some issues with a wrapper script.

Talking about Docker, I do see it referenced in the Nova code,
but I'm unsure what that means.. Does Docker work with Openstack,
or is it just a reference of known hypervisors?

> and I wouldn't advise to attempt using it unless you already have a fully
> working OpenStack deployment working with KVM already.

I thought (I've tested "Them All (™)" - as in every hypervisor known
to man - about ten years ago when I eventually decided on Virtualbox)
that KVM and Xen was containers. It turns out I've been mixing them
up in my head.

I've had a quite heated discussion with my mates on Saturday that's
been doing this at my previous work (sometimes I'm slow to "get it" :),
and it turns out that I can/should use KVM for the "real" VMs.

It's not any where near as good as Virtualbox (or even VMware), but
it'll do - all I really need (in that part) is to boot a custom kernel
and modules.. I.e., full separation.

> Canonical has been working hard on supporting LXC through LXD, which is
> an attempt to provide the same kind of support as for KVM with LXC
> containers (ie: with support for live migration, networking and so on).

Yeah, that's what I tried to. The combination isn't half bad, and one day
I'm sure it will be amazing (there IS a couple of things I like better
about it than Docker), but at the moment.. Rubbish, is one word for it :).

> LXD isn't even uploaded in Debian yet…

I noticed, I had to take the Ubuntu source package and some other bits
and pieces from them and back port it myself. Wasn't that much work, just
finding the right packages to build with, golang was the most troublesome.

> I hope this helps,

It does, thank you very much! It wasn't good news, but thanx anyway :)

The fact that I might need to have TWO types of Compute nodes is going
to throw a spanner in the works, but I guess I have no choice :(.

I'll see how much of a problem this will turn out to be once I start
getting something working. One reason to do this in the first place
is to learn about Openstack - I'm going to need that professionally
eventually I'm sure, so "to birds with one stone" :).
You know, boys, a nuclear reactor is a lot like a woman.
You just have to read the manual and press the right buttons
- Homer Simpson

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