Live migration between Intel and AMD

[kenneth_vkd]

Hi
We are looking into rotating our fleet of servers to gain more performance with less physical space used by going from Intel Xeon Gold 6226R to AMD Epyc Genoa based systems instead.
Until now we have been primarily using Intel Xeon-based nodes in our cluster, but for our workloads we get better performance and a lower price by switching.

On other hypervisor platforms, the live migration of running virtual machines is not supported when going between AMD and Intel. So to migrate we would need to turn off a VM, migrate it and start it up again.
On PVE 8.2 we use the current default CPU of "x86-64-v2-AES" for all virtual machines. Can we live migrate from Intel to AMD with this config or would we need to turn off each VM, migrate it and boot it up again?

 

[gfngfn256]

AFAIK x86-64-v2-AES is cross-platform compatible as per docs. However (as you probably know) live-migration can sometimes offer surprises & no two migrations are the same.

Best way to test - setup a new typical (your environment) VM on an Intel-node & then live-migrate it to an AMD-node.

 

[fiona]

Hi,
even when using a generic CPU type, live migration between hosts with CPUs from different vendors is not guaranteed to work: https://pve.proxmox.com/pve-docs/chapter-qm.html#_online_migration

• The hosts have CPUs from the same vendor with similar capabilities. Different vendor might work depending on the actual models and VMs CPU type configured, but it cannot be guaranteed - so please test before deploying such a setup in production.

You might get lucky and it works in your specific case, but in principle, it can also break on future kernel or QEMU updates.