[lxc-users] LXD move, how to reduce downtime without live migration

[Benoit GEORGELIN - Association Web4all]

Good evening 
I'm running into a problem with LXD live migration, so I can't use live migration 
I have this kind of error: 
error: Error transferring container data: migration restore failed
(00.018254) Warn  (criu/apparmor.c:421): apparmor namespace /sys/kernel/security/apparmor/policy/namespaces/lxd-router-gw_<var-lib-lxd> already exists, restoring into it
(00.025064) Warn  (criu/cr-restore.c:853): Set CLONE_PARENT | CLONE_NEWPID but it might cause restore problem,because not all kernels support such clone flags combinations!
(00.246825)      1: Warn  (criu/autofs.c:77): Failed to find pipe_ino option (old kernel?)
(00.249058) Error (criu/cr-restore.c:1024): 15755 killed by signal 11: Segmentation fault
(00.268144) Error (criu/cr-restore.c:1024): 15755 killed by signal 9: Killed
(00.288290) Error (criu/mount.c:3275): mnt: Can't remount root with MS_PRIVATE: No such file or directory
(00.288297) Error (criu/mount.c:3285): mnt: Can't unmount .criu.mntns.K2nNqG: No such file or directory
(00.288301) Error (criu/mount.c:3290): mnt: Can't remove the directory .criu.mntns.K2nNqG: No such file or directory
(00.288627) Error (criu/cr-restore.c:1890): Restoring FAILED. 


I thought it was because of the kernel, but it looks supported : 4.4.0-47-generic 

So, I would like to move my containers. Moving without live migration have a big impact as the container have to be stopped. And the bigger, the longer ^^ 

I'm using ZFS as backend storage. 
LXD/LXC version 2.8 on source 
LXD/LXC version 2.12 on destination 

Do you have any idea how i can move it and reduce the downtime ? 
Like doing an rsync while the container is running, stop the container, rsync while it is stopped so I save time. 

My idea was eventually to create the container on destination node. Same name , same configuration 
rsync the content of the storage from source to destination twice (one while running, one while stopped) 
then start the container on the destination node 

If you have any idea, it would be appreciated . 

In case you wanna joint the new forum, here is the link of the topic : https://discuss.linuxcontainers.org/t/lxd-move-how-to-reduce-downtime-without-live-migration/63

Cordialement, 

Benoît G