Quoting Matt Helsley (matthltc@xxxxxxxxxx): > > So far, so good. Note that I couldn't use upstart for my init bc upstart > > uses inotify, which we don't yet checkpoint. The kernel is compiled without > > Interesting, I didn't know that. What does upstart use inotify for? Dunno :) I was quite put out though. > > There are two issues: > > > > 1. how to re-create the mounts. Kernel doesn't do it yet. There > > isn't (that I know of) a clean way to hook lxc-restart to do it. > > Comments? > > It's incomplete but I think you can save the most important portions of > a mount namespace with a simple 1-line command: > > lxc-attach -n cr1 cat /proc/self/mountinfo > cr1.mountinfo > > It's incomplete because: > > 1. It does not adequately address cross-mount-ns bind mounts (IIRC). > > 2. It won't work for nested containers (though I don't know if > lxc supports this already it's not *too* far fetched > to expect folks will ask for it in the future). We can > extend the hack to deal with this by making a small > change in sys_checkpoint but I can't see how to fix #1 > without doing it all in-kernel anyway. Heck, for these examples I don't mind just having a sort of dummy fstab file which both the dummy init and restart use. > The restoration of the mounts is not scriptable however. It involves > parsing the mountinfo file and coordinating the mounts with those done by > lxc itself during lxc-restart. I honestly haven't looked at that closely I'd be fine with requiring some bit of hand-parsing. But right, even once we get a list of the mounts to be restored, I don't know of any good way to get those mounts re-created at the right time. I suppose I could hack lxc-restart to do it. But I'm sort of hoping we can get something less hacked and more true to the 'real' upstream code. > enough yet to say how pretty/ugly that'd be but it entails > modifications to lxc-restart itself. And since #1 above would still > be an issue I'm not sure it's worth doing it that way. So do you know of anyone who's been working on re-creation of mounts in the kernel? If not, what have you been doing, hand-scripting all container creation, checkpoint, and restart? thanks, -serge _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
