Live migration, CPU question.

[Proximate]

I read this in the documentation.

This has a downside though. If you want to do a live migration of VMs between different hosts, your VM might end up 
on a new system with a different CPU type. If the CPU flags passed to the guest are missing, the qemu process will stop.
To remedy this Qemu has also its own CPU type kvm64, that Proxmox VE uses by defaults. kvm64 is a Pentium 4 look 
a like CPU type, which has a reduced CPU flags set, but is guaranteed to work everywhere.

In short, if you care about live migration and moving VMs between nodes, leave the kvm64 default. If you don’t care about 
live migration or have a homogeneous cluster where all nodes have the same CPU, set the CPU type to host, as in theory
this will give your guests maximum performance.

The question is, do the CPU's on cluster hosts have to use the exact same CPU's or same family?
To install rocky linux, I had to use 'host' as the CPU type.
Say I want to live migrate 'host' CPU based guests from a host using E5-2650 CPU's to a host using E5-2660 CPU's. Would that work?
The CPU's are essentially the same other than number of cores.

 

[tuxis]

It might work, it might not work. That's as clear as it might get with a host-cpu. IIRC it also depends on the instructions a VM uses (or starts using after migration). If the original CPU supports it, and the to-migrated-to CPU doesn't, you're screwed as well.

 

[Proximate]

Got it.
If I test and it goes well, assuming the CPU's don't change, do you feel from then on, I can count on live migration to work properly?