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

[Benoit GEORGELIN - Association Web4all]

----- Mail original -----
> De: "Tamas Papp" <tamas.papp at rtfm.co.hu>
> À: "lxc-users" <lxc-users at lists.linuxcontainers.org>
> Envoyé: Jeudi 27 Avril 2017 01:59:34
> Objet: Re: [lxc-users] LXD move, how to reduce downtime without live migration

> On 04/27/2017 03:43 AM, Benoit GEORGELIN - Association Web4all wrote:
> > 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 use zfs backend, why don't you use 'zfs send/recv'?

> tamas

Yes, I was not sure about the possibility to migrate the datas of a container from one host to another one just like that. I do it with snapshot for backups 
Thanks