What is the current status online migration between Intel and AMD

[sa10]

What is the current status of support online migration VMs from Intel to AMD and AMD to Intel?
I read in the manual: CPU type kvm64 is guaranteed to work everywhere.
But I found in the forum the discussions about problems.

https://forum.proxmox.com/threads/can-i-move-vms-from-intel-to-amd.63798/
https://forum.proxmox.com/threads/problem-when-live-migrating-from-intel-to-amd-server.42270/

 

[t.lamprecht]

What is the current status of support online migration VMs from Intel to AMD and AMD to Intel?

Let's say it this way: Do not mix vendors If you need a real guarantee for it to work, one can even run into issues when using the same vendor, if models are too different (e.g., ten year old atom with current Xeon, or something like that, may sometimes give you hiccups)

I read in the manual: CPU type kvm64 is guaranteed to work everywhere.

That a VM starts on both in general, yes that's guaranteed, but it simply cannot be guaranteed that live migration of a VM works 100%.
There are simply to many little to possible big differences in behavior between such models, even if QEMU tries to abstract away as much as possible with using a common denominator model like kvm64, can only mask feature registers and such official documented interactions, but it simply cannot be made 100% identical in timings, management engine behavior and much more.

So, while you may have a chance of it to work, it may also fail arbitrarily with some VMs, or at some point.

TLDR; if you want to be sure use the same vendor and ideally even a similar CPU model. Else, your mileage may vary.

 

[ness1602]

I have 6 node cluster with almost all intel generations, and all works well. As for the AMD servers, i still don't have any, but i guess when lenovo lowers prices we could buy one.