[lxc-users] live migration using lxd 0.4

[Tycho Andersen]

On Tue, Mar 24, 2015 at 04:36:53PM +0100, Bostjan Skufca wrote:
> On 24 March 2015 at 15:34, Tycho Andersen <tycho.andersen at canonical.com>
> wrote:
> 
> > Hi,
> >
> > You'll also find that you need some other stuff to do live migration
> > (not documented anywhere, unfortunately):
> > ...
> > 2. only non-uidmapped containers work (you can do this in lxd by just
> >    setting the uidmap for lxd to be 0-65536, or by setting the uidmap
> >    in the container's raw.lxc config)
> >
> 
> What is the reason for this? Missing implementation or some technical
> obstacle? Just curious.

I think just missing implementation at this point (both in kernel and
userland). The problem is that once you enter the user namespace, you
can't do a lot of stuff that the restore code needs to do. The CRIU
folks introduced usernsd a couple of months ago to deal with this
(i.e. a daemon that performs the privileged requests on behalf of the
process), but it is still very young and the last I played with it it
didn't quite work.

You can see some of their discussion: http://criu.org/UserNamespace

Tycho

> 
> 
> b.

> _______________________________________________
> lxc-users mailing list
> lxc-users at lists.linuxcontainers.org
> http://lists.linuxcontainers.org/listinfo/lxc-users