Re: xen/stable-2.6.32.x xen-4.1.1 live migration fails with kernels 2.6.39, 3.0.3 and 3.1-rc2

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Thu, Aug 25, 2011 at 09:15:14AM +0200, Andreas Olsowski wrote:
> 
> > Which sounds like the patch above should have fixed. Again, did you
> > check your binary and source tree to see if you have the mentioned
> > patch?
> 
> Yes at the time i tested it the patch was in 4.1-testing and 4.2, so
> i do have the patch applied. It had the desired effect, i can
> migrate TO the host with more RAM, but i still cannot migrate guests
> that have been created on it FROM that host.

Ok, so you do have a workaround for that right now - and we kind of
know that is something still amiss with the MFN calculations when
migrating.

My todo list is not getting any shorter sadly so not sure when I will
get to try this out. But let me do that when I get my 32GB machine
working again.

> 
> I can however create the guest somewhere else, migrate it there and
> then migrate it back.

Yeah, that really points to either the tools not liking the
MFN being too high or the hypervisor. Or the save/resume path in the
Linux kernel is failing silently and sticking in invalid MFNs
as it can't deal with higher MFNs.

In other words - need to run this to figure out.

Unless you are up for helping out by debugging the code a bit and
seeing if you can come with a fix?