[CRIU] how to lively migration a vm container?

[Pavel Emelyanov]

On 05/13/2014 07:32 PM, Bing X wrote:
> As it's clear in the hierarchy, I have 3 docker containers running under docker.io
> <http://docker.io>; for 2 of them, the ssh connected, one is bash (local container)..
> 
> All of these images stored under /var/lib/docker/graph/
> 
> but why I couldn't successfully dump any of them? Please help me take a look.

Check the criu's log files, the dump errors are written into it.

> thanks!
> 
> 
> On Mon, May 12, 2014 at 7:37 PM, Bing X <xiebingbing at gmail.com <mailto:xiebingbing at gmail.com>> wrote:
> 
>     I am running two docker containers with ssh service under /root. in one of containers,
>     I run a IOR benchmark, which is live, and which is the one I want to dump.
> 
>     what are the mountpoints visible by it? --- what's this mean?

Linux allows to create so called mount points in the FS tree. Different processes
may see different mount points. In your case the docker container sees that the
/etc/hosts file is a mount point with external source. What is it?

>     here's the pid hierarchical structure:
>     2569 ?        Sl     0:12  \_ /usr/bin/docker.io <http://docker.io> -d
>      5984 ?        Ss     0:00      \_ /bin/sh -c /usr/sbin/sshd -D
>      6016 ?        S      0:00      |   \_ /usr/sbin/sshd -D
>     12551 ?        Ss     0:02      |       \_ sshd: root at notty
>     12563 ?        Ss     0:00      |           \_ bash -c cd /root/io_run; bash ./run.sh
>     12564 ?        S      0:00      |               \_ bash ./run.sh
>     14105 ?        S      0:00      |                   \_ mpirun ./IOR -w -z -e -f ./parameter.script
>     14106 ?        S      0:00      |                       \_ /usr/bin/hydra_pmi_proxy --control-port 280bce53d979:54710 --rmk user --launcher ssh --demux poll --pgid 0 --retries 10 --proxy-id 0
>     14107 ?        S      0:00      |                           \_ ./IOR -w -z -e -f ./parameter.script
>      9017 ?        Ss     0:00      \_ /bin/sh -c /usr/sbin/sshd -D
>      9034 ?        S      0:00          \_ /usr/sbin/sshd -D
> 
> 
> 
> 
>     On Mon, May 12, 2014 at 7:29 PM, Pavel Emelyanov <xemul at parallels.com <mailto:xemul at parallels.com>> wrote:
> 
>         On 05/13/2014 03:13 AM, Bing X wrote:
>         > What does it mean: I run criu dump with a pid I assume it is a container process, but get an error as:
>         >
>         > Error (mount.c:356): 119:./etc/hosts doesn't have a proper root mount
>         > Error (cr-dump.c:1870): Dumping FAILED.
>         >
>         > what I should change?
> 
>         The /etc/hosts is bind-mounted file and source of it sits out of
>         the scope of what you dump.
> 
>         Please, describe your setup -- what app do you dump, in what namespaces
>         does it live and what are the mountpoints visible by it?
> 
>         Thanks,
>         Pavel
> 
> 
> 
> 
>     -- 
>     Thanks
>     Bing
> 
> 
> 
> 
> -- 
> Thanks
> Bing