[CRIU] question on live migration for docker container using CRIU

[Saied Kazemi]

Mona,

Pertaining to my previous reply, I just sent a patch for docker_cr.sh
helper script to dynamically determine the right dockerinit file.  It
may be easier for you to apply this patch and use it going forward.

--Saied



On Fri, Jan 2, 2015 at 9:43 AM, Saied Kazemi <saied at google.com> wrote:
> Hi Mona,
>
> As Pavel pointed out, the error is due to not being able to bind mount
> an external file.  But this is not because a the --ext-mount-map
> command line option is missing.  It's because docker_cr.sh does not
> know the dockerinit file name in /var/lib/docker/init (by default, it
> assume Docker 1.0.0).
>
> Since you are running Docker 1.4, you need to change the following
> BIND_MOUNT line in docker_cr.sh to reflect what you have in
> /var/lib/docker/init:
>
> # since older versions of docker bind mount /.dockerinit but
> # the path cannot be queried by docker inspect, we have to
> # hard code it here
> BIND_MOUNT[/.dockerinit]="${DOCKER_HOME}/init/dockerinit-1.0.0"
>
> Hope this helps.
>
> --Saied
>
>
> On Wed, Dec 31, 2014 at 2:28 AM, Pavel Emelyanov <xemul at parallels.com> wrote:
>> On 12/31/2014 04:36 AM, mona kashkoush wrote:
>>>
>>> i tried to  do a live migration for docker container using CRIU 1.4 but dumping failed and this error appeared
>>>
>>> $  criu dump --tree <pid> --images-dir <path-to-existing-directory> --leave-stopped
>>>
>>> Error (mount.c:624): 125:./etc/hosts doesn't have a proper root mount
>>> Error (files-reg.c:764): Unaccessible path opened 52:21244, need 5:1029
>>> Error (cr-dump.c:1601): Dump files (pid: 3906) failed with -1
>>> Error (cr-dump.c:1964): Dumping FAILED.
>>>
>>> and when i used the automated script "docker_cr.sh " for docker container migration , this succeeded for
>>> dumping  but failed for restoring and this error appeared
>>>
>>> $ /src/criu-1.4/contrib/docker_cr.sh -r -v <container_id>
>>>
>>> restore failed
>>> (00.072030)      1: Error (mount.c:1543): Can't mount at ./.dockerinit: No such file or directory
>>
>> Hm... This looks like some missed --ext-mount-map thing. Can you find out the
>> exact command line docker_cr.sh calls CRIU with?
>>
>> Hopefully Saied (in Cc) can also advise something.
>>
>>> (00.072076) Error (cr-restore.c:1838): Restoring FAILED.
>>>
>>> * this is information about docker which i used
>>>
>>> Storage Driver: aufs
>>>  Root Dir: /var/lib/docker/aufs
>>>  Dirs: 67
>>> Execution Driver: native-0.2
>>> Kernel Version: 3.13.0-43-generic
>>>
>>> thanks for your time
>>>
>>> --
>>> Mona Salah
>>> Research Assistant
>>> IRI institute
>>> The City of Scientific Research and Technology Applications,Alex , Egypt
>>>
>>>
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>>> CRIU mailing list
>>> CRIU at openvz.org
>>> https://lists.openvz.org/mailman/listinfo/criu
>>>
>>