Re: Migration and Node parameter

[Andre Przywara <andre.przywara@amd.com>]

Stefan de Konink wrote:
>     def domain_migrate(self, domid, dst, live=False, port=0, node=-1,
> ssl=None):
>         """Start domain migration.
> ...
>         @keyword node: use node number for target
>         @type node: int
 > ...
> What does the node parameter do in this context?

This means the NUMA node the new guest should be created on. Newer Xen 
versions create guests on a single node and choose the least used one. 
If later the system load changes, it can become imbalanced in respect to 
equal load on all nodes. In this situation you can manually move a guest 
to another NUMA node. (NUMA literature often uses the term "NUMA domain" 
instead of node, but for obvious reason I try to avoid this term in Xen)
Using localhost migration for this purpose isn't the smartest solution, 
but was fairly easy to implement ... and works.
See unstable c/s 17148 for the code.

Regards,
Andre.

-- 
Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany
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