[lxc-devel] Change rootfs pinning mechnism

[Christian Seiler]

Hi there,

> I would suggest to add a config switch to choose between early
> unlinking and removing at shutdown. Because I'm using a setup where
> the rootfs are shared between several hosts and an container may be
> run on any of it. For this usecase, the rootfs pinmarker is a (not
> perfect but) good signal that a rootfs is in use. Even in the case of
> non-shared rootfs's there might be other usecases where this marker 
> is
> useful indicator.

I could add a configuration option for that, if Serge and
Stéphane agree.

> One more: I'm not up-to-date with the development, but is/was the
> successful creation of the markerfile also a necessary condition to
> startup a container? If yes, I expect that this is broken by the
> unlink feature because right after unlinking one can create a new 
> file
> with "this" name.

It was, but there was/is no O_EXCL in the open() command, so a
pre-existing .hold file was never a reason for the container
startup to fail. (Which was necessary because they were never
removed on shutdown previously.) So in that sense, this behavior
hasn't changed.

-- Christian