On 07/17/2015 07:28 AM, Daniel P. Berrange wrote:
On Fri, Jul 17, 2015 at 06:58:46AM -0600, David Medberry wrote:
HI Daniel,
Yep found that all out.
Now I'm struggling through the NUMA mismatch. NUMA as there are two cpus.
The old CPU was a 10 core 20 thread thus 40 "cpus", {0-9,20-29} and then
{10-19,30-39} on the other cell. The new CPU is a 12 core 24 thread.
Apparently even in kilo, this results in a mismatch if I'm running a 2 VCPU
guest and trying to migrate from new to old. I suspect I have to disable
NUMA somehow (filter, etc) but it is entirely non-obvious. And of course
I'm doing this again in OpenStack nova (not direct libvirt) so I'm going to
do a bit more research and then file a new bug. This also may be fixed in
Kilo but I"m not finding it (and it may be fixed in Liberty already and
just need a backport.)
My apologies for not following up to the list once I found the Kilo
solution to the original problem.
The fact that Nova doesn't rewrite numa topology on migrate is a known
bug which Nikola is working on fixing in Liberty. IIRC, you ought to be
able to avoid it by just disabling the NUMA schedular filter.
I wonder if this is due to the "isolate an instance on a numa node" work
combined with the fact that numa topology doesn't get rewritten. If so, it
might be "fixed" by commit 41ba203 on stable/kilo.
If the guest is using dedicated CPUs then there's no fix, it's just broken for
live/cold migration, resize, and evacuate.
Chris
_______________________________________________
OpenStack-operators mailing list
[email protected]
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
