[CRIU] Re, Issues dumping MySQL process

[Pavel Emelyanov]

On 03/19/2015 06:25 PM, Hui Kang wrote:
> Hi, Pavel,
> Thanks for you comment. I have another question about dump the image of a MySQL and restore it on a different host.
> 
> I used the command "criu dump mysql-pid -j" 

Well, -j is not needed if MySQL is started as daemon.

> to dump a MySQL. And then I copy al the dumped images to another host. After I run "criu restore". It complains
> about "bad size of /var/log/mysql/error.log and /var/lib/mysql/".

Yup, that's the attempt to protect restoring on bad files.

> After I copy these two directory from the original host to the restored host, the mysql process can be restored.
> My question is during dumping, can I also dump all the related file and directory? 

With CRIU -- no. We deliberately avoid messing with the filesystem as handling it
heavily depends on the use case. E.g. for seamless kernel update nothing should
be done with the FS.

For live migration -- non shared filesystems should be copied, but this can and
should be done in a more effective manner than plain scp :) In order to address
that and make live migration easier we started the P.Haul project that uses criu
to dump and restore tasks and handles images copying, iterations, memory post-
and pre-copy as well as FS synchronization. The project is not as active as CRIU
and quite raw at the moment, but I plan to resurrect the activity by April :) So 
you're also welcome to join!

P.Haul lives at http://criu.org/P.Haul

> Thanks.
> 
> - Hui

Thanks,
Pavel