On Wed, Dec 08, 2010 at 04:53:22AM +0000, Serge E. Hallyn wrote: > What I've done so far: > > created a KVM vm and installed up-to-date maverick > add-apt-repository ppa:appcr/ppa > apt-get update && apt-get dist-upgrade > apt-get install libvirt-bin lxc linux-image-2.6.34-1cr4 > sed -i 's/GRUB_DEFAULT=0/GRUB_DEFAULT="Ubuntu, with Linux 2.6.34-1cr4-generic"/' /etc/default/grub > update-grub > > replaced 122 with 123 in /etc/libvirt/qemu/networks/default.xml and /var/lib/libvirt/network/default.xml > reboot > > # The following should go into an upstart script shipped with the appcr packages > # as they must be done on each boot > chmod 666 /dev/pts/ptmx > rm /dev/ptmx > ln -s /dev/pts/ptmx /dev/ptmx > mkdir -p /cgroup > mount -t cgroup cggroup /cgroup/ > echo /bin/remove_dead_cgroup.sh > /cgroup/release_agent > echo 1 > /cgroup/notify_on_release > # > > cat > /etc/lxc-basic.conf << EOF > lxc.network.type=veth > lxc.network.link=virbr0 > lxc.network.flags=up > EOF > > lxc-create -f /etc/lxc-basic.conf -n cr1 -t ubuntu > cd /var/lib/lxc/cr1/rootfs/sbin > mv init upstart > > cat > init << EOF > #!/bin/sh > rm -f /shutdown > hostname cr1 > > exec 0<&- > exec 0</dev/null > exec 1>&- > exec 1>nohup.out > exec 2>&- > exec 2>nohup.out > > mkdir -p /tmp2 > mount --bind /tmp2 /tmp > > mount -a > mount -t proc proc /proc > mount -t tmpfs varrun /var/run > mkdir /var/run/network > mkdir /var/run/sshd > ifconfig eth0 192.168.123.21 up > screen -A -d -m -S console > > /usr/sbin/sshd > while [ ! -f /shutdown ]; do > sleep 4s > done > EOF > > lxc-start -n cr1 > > (in another console) > ssh 192.168.123.21 > screen -r > ps > ctrl-a d > exit > > lxc-freeze -n cr1 > lxc-checkout -n cr1 -S /root/cr1.s1 > > 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? > ipv6 bc that was also causing a problem (though I thought ipv6 was supported > for checkpoint?) and therefore I needed a custom libvirt package which didn't > break when ipv6 is not there. > > The problem now is when attempting to restart: > > lxc-stop -n cr1 > lxc-restart -n cr1 -S /root/cr1.s1 > > 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. 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 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. Cheers, -Matt Helsley _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
