Stability of migration?

[John Byrne <john.l.byrne@hp.com>]

Hi,

With xen-unstable changset 10333:360f9dc71f51, live migration is not 
reliable. Migrating an active domain (I use a kernel build in my test) 
back and forth between two machines will result in the build or the 
domain crashing. I tweaked xc_linux_save.c to enable the verify pass 
without outputting all the debugging messages and I can see that one or 
two pages do not get a data match in the log.

I have yet to see a failure of the domain with non-live migration, but I 
sometimes see a data mismatch on a page during the verification. Which 
would indicate that either suspend doesn't mean what I think it does or 
pages of a suspended VM are being altered when they shouldn't be.

So, I guess I'll start with the easy question: should non-live migration 
ever have a page fail to verify? If not, how can I identify the source 
of the problem?

The harder question: how to identify the source of the corruption in 
live migration?

Thanks,

John Byrne