[systemd-devel] Should user mode linux register with machined?

[Lennart Poettering]

On Wed, 17.09.14 10:24, Richard Weinberger (richard.weinberger at gmail.com) wrote:

> On Wed, Sep 17, 2014 at 1:09 AM, Zbigniew Jędrzejewski-Szmek
> <zbyszek at in.waw.pl> wrote:
> > On Tue, Sep 16, 2014 at 05:31:05PM +0200, Thomas Meyer wrote:
> >> Hi,
> >>
> >> I wrote a small patch for user-mode linux to register with machined by
> >> calling "CreateMachine". Is this a good idea to do so?
> > Yes, this sounds useful. After all is just another mechanism of
> > virtualization, and in this case can be treated similarly to
> > containers and vms.
> 
> I still want a sane reason and a usecase for that.
> Can someone please educate me? :-)
> 
> Please note that also qemu does not register itself to systemd.
> libvirt does. I think going down this path makes also sense for UML
> as libvirt has a UML driver too.
> qemu and the UML ELF image are the low level building blocks.
> Managers like libvirt should register the virtual machines created by
> LXC, UML, qemu, etc.. to systemd.

It's a bit more complex. While UML, qemu, kvm, currently don't, LXC,
systemd-nspawn and libvirt-lxc all do talk directly to machined. (Note
that LXC and libvirt-lxc are separate codebases, the latter is *not* a
wrapper around the former).

So, dunno, it really is up to how you intend UML to be used. If UML
shall be nice and useful without libvirt, then it's worth doing the
registration natively, but it's also OK to just leave this to libvirt,
if that's your primary envisioned usecase...

Lennart

-- 
Lennart Poettering, Red Hat