[CRIU] CRIU Queries Live Migration V/S Disk-less Migration

[Prashant Chillabatte]

> When you just live migrate a container you should keep images with memory
contents
> on source node FS, then copy them to the destination one.
Using shared file system eliminates the need of copying any thing(memory
and context) from source node to destination node. According to this live
migration should be faster then disk-less migration. This that right?
> In disk-less live migration
> you can send memory dumps directly to the destination host using page
server


Thanks,
Prashanth Chillabatte

On Mon, Oct 19, 2015 at 2:22 PM, Pavel Emelyanov <xemul at parallels.com>
wrote:

> On 10/15/2015 06:53 PM, Prashant Chillabatte wrote:
> >
> > Hello All,
> >
> > I started using criu from few days back. I have few quires after using
> CRIU for few weeks.
> >
> > I would really appreciate your helping hands on understanding CRIU
> better.
> >
> > 1st Query:
> > I failed to understand the difference between the live migration and
> disk-less migration.
> >
> >    In live migration
> >
> > ●Take the snapshot of the process
> > ●Copy them into some shared folders.[involves creating images files of
> both memory and context and pasting/dumping at a directory ]
> >
> >    In disk-less migration
> >
> > ●Take the snapshot of the process
> > ●Transfer the process memory related files[Transfer involves creating
> memory image files and pasting/dumping them on the restore side ] ->> this
> step looks like same as coping into shared folder in live migration
> > ●Copy process context image files using scp.
> >
> >    I fail to understand the difference, can someone give a better
> understanding of the same.
>
> When you just live migrate a container you should keep images with memory
> contents
> on source node FS, then copy them to the destination one. In disk-less
> live migration
> you can send memory dumps directly to the destination host using page
> server.
>
> > 2nd Query:
> > I want to know about page-server, what does page-server do?How different
> it is from secure copying like scp.
>
> The main advantage when using page server is that you don't have to keep
> memory dumps
> in two places -- source node and destination one.
>
> > 3rd Query:
> > What does live migration exactly means?
> > My understanding after using CRIU for few weeks:
> > ■Process running on node 1
> > ■Checkpointthe process
> > ■Restore the process on the 2nd node
> >
> > And the process/application/service under migration has downtime
> equivalent to time elapsed between checkpoint and restore.
> >
> > Correct me if i am wrong.
> >
> > Thanks,
> > Prashanth Chillabatte
> >
> >
> >
> > _______________________________________________
> > CRIU mailing list
> > CRIU at openvz.org
> > https://lists.openvz.org/mailman/listinfo/criu
> >
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openvz.org/pipermail/criu/attachments/20151020/df97e6aa/attachment.html>