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Line 1: − =Prepare a Linux Container (CT)=+ − − * A console should be disabled (lxc.console = none) − * udev should not run in CT ($ mv /sbin/udevd{,.bcp}) − == Prepare a host environment ==+ − * Mount cgroupfs+ − $ mount -t cgroup c /cgroup − * Create a network bridge − # cat /etc/sysconfig/network-scripts/ifcfg-br0 − DEVICE=br0 − TYPE=Bridge − BOOTPROTO=dhcp − ONBOOT=yes − DELAY=5 − NM_CONTROLLED=n − $ cat /etc/sysconfig/network-scripts/ifcfg-eth0 − DEVICE="eth0" − NM_CONTROLLED="no" − ONBOOT="yes" − BRIDGE=br0 − − * Download an OpenVZ template and extract it. − curl http://download.openvz.org/template/precreated/centos-6-x86_64.tar.gz | tar -xz -C test-lxc − * Create a config files+ − $ cat ~/test-lxc.conf + − lxc.console=none+ − lxc.utsname = test-lxc+ − lxc.network.type = veth+ − lxc.network.flags = up+ − lxc.network.link = br0 − lxc.network.name = eth0 − lxc.mount = /root/test-lxc/etc/fstab − lxc.rootfs = /root/test-lxc-root/ − $ cat /root/test-lxc/etc/fstab+ − none /root/test-lxc-root/dev/pts devpts defaults 0 0 − none /root/test-lxc-root/proc proc defaults 0 0 − none /root/test-lxc-root/sys sysfs defaults 0 0 − none /root/test-lxc-root/dev/shm tmpfs defaults 0 0 − * Register CT+ − $ lxc-create -n test-lxc -f test-lxc.conf + + − * Start CT+ − $ mount --bind test-lxc test-lxc-root/ − $ lxc-start -n test-lxc − + − + − + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
→Troubleshooting: to level2
== Requirements ==
==Requirements==
You should have built and installed a recent (>= 1.3.1) version of CRIU.
== Checkpointing and restoring a container ==
==Create CT==
LXC upstream has begun to integrate checkpoint/restore support through the lxc-checkpoint tool. This functionality has been in the recent released version of LXC---LXC 1.1.0 , you can install the LXC 1.1.0 or you can check out the development version on Ubuntu by doing:
<source lang="bash">
sudo add-apt-repository ppa:ubuntu-lxc/daily
sudo apt-get update
sudo apt-get install lxc
</source>
Next, create a container:
<source lang="bash">
sudo lxc-create -t ubuntu -n u1 -- -r trusty -a amd64
</source>
And add the following lines (as above) to its config:
= Dump/Restore a Linux Container =
<source lang="bash">
==Installation==
cat | sudo tee -a /var/lib/lxc/u1/config << EOF
* Install [[CR tools]] and all requirements according with [[Installation | instructions]]
# hax for criu
lxc.console = none
lxc.tty = 0
lxc.cgroup.devices.deny = c 5:1 rwm
EOF
</source>
Finally, start, and checkpoint the container:
<source lang="bash">
sudo lxc-start -n u1
sleep 5s # let the container get to a more interesting state
sudo lxc-checkpoint -s -D /tmp/checkpoint -n u1
</source>
At this point, the container's state is stored in /tmp/checkpoint, and the filesystem is in /var/lib/lxc/u1/rootfs. You can restore the container by doing:
<source lang="bash">
sudo lxc-checkpoint -r -D /tmp/checkpoint -n u1
</source>
And then, get your container's IP and ssh in:
<source lang="bash">
ssh ubuntu@$(sudo lxc-info -i -H -n u1)
</source>
== Troubleshooting ==
=== Error (mount.c:805): fusectl isn't empty: 8388625 ===
Dumping of fuse filesystems is currently not supported. Empty the container's <code>/sys/fs/fuse/connections</code> and try again.
=== Error (mount.c:517): Mount 58 (master_id: 12 shared_id: 0) has unreachable sharing ===
CRIU doesn't yet support shared mountpoints as LXC does; make sure your rootfs is on a non-shared mount.
== External links ==
* [https://www.youtube.com/watch?v=a9T2gcnQg2k&feature=youtu.be&t=18m8s The New New Thing: Turning Docker Tech into a Full Speed Hypervisor] - Talk of Tycho Andersen with demo of migration LXC container with Doom inside
* [https://github.com/tych0/presentations/blob/master/ods2014.md Demo script]
[[Category: HOWTO]]
[[Category: Live migration]]