Live migraton with CPU = host and procs from E5-2600 family but not exactly the same

[mailinglists]

Hi guys,

in order to do a live migrate, all cpu options must be available on both hosts.
Must the frequency also match?

Do you guys think live migration should be possible when guest has CPU set to host, and one migrates to different proc, but in the same family?

Like from E5-5260 to E5-5270 or E5-2665 or E5-2643 etc.. you get the point.

 

[LnxBil]

I do not know for sure (haven't tried yet), but it could work.

More interesting for me:
Why do you have cpu=host machines? I live-migrated cpu=kvm machines from amd to intel and back, often it works, sometimes it does not.

 

[joshin]

Yes. I never had problems moving VMs between any of our Xeon 5600 series servers regardless of frequency.

And with the CPU set to SandyBridge or lower, I've had almost perfect success moving VMs between E5-2600 and E5-2600v2 servers.

For AMD <-> Intel, it's a roll of the dice.

 

[mailinglists]

cpu=host gives better performance

 

[joshin]

cpu=host gives better performance

Reliability > Performance