[Lxc-users] Live Migration of LXC

[Serge E. Hallyn]

Quoting Daniel Lezcano (daniel.lezcano at free.fr):
> On 10/24/2011 02:07 PM, Ulli Horlacher wrote:
> > On Mon 2011-10-24 (12:03), Greg Kurz wrote:
> >
> >> C/R and live migration is a complicated matter for LXC containers.
> > I have assumed nothing else...
> >
> >
> >> No status for the moment... I guess people who really want migration
> >> should participate
> > Not every LXC (admin-)user is a kernel hacker, too. I am fluent in Perl
> > programming, but not in C.
> >
> >
> >
> >> at least to show kernel maintainers there's a demand for it.
> > How can we do this? Send mass e-mails (spam) to the kernel maintainers? :-)

Not out of the blue.  But you can watch lkml and, when related emails come
by and, especially, when the community discusses whether the patches are
worthwhile, then chime in.

> Different approaches were proposed:
> 
>  * CR from userspace only : we know it is not possible to fully support
> the CR with this approach.

But since so far the alternative to this partial support is *zero*
support, I've been tempted to go back to one of these implementations.

>  * CR from the kernel space : the CR is monolithic and is very intrusive
> in the different kernel subsystems and their interactions make the
> maintenance very complicate for the owner of the subsystem. This is why
> this approach has been nacked from the community.

It was never officially nacked, fwiw.  But the effort appears to be
dead, and the effort has shifted to the hybrid approach.

>  * a hybrid CR where the userspace collects CR information exported from
> the kernel. IHMO, this approach is the better in terms of maintenance
> and flexibility.

If some of those patches will make it upstream, then if nothing else
we can look into augmenting the purely-userspace c/r with that support.

> The latter is for the moment investigated by the containers@ community
> and AFAIK this approach has a better chance to be accepted but there is
> still a lot of work to do.

I personally feel pessimistic about it, but we'll see.

-serge