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Problematic VM migration between hosts [message #53802]

Thu, 22 December 2022 21:23

jjs - mainphrame
Messages: 43
Registered: January 2012

Member

I have 3 openvz hosts, all with slightly differing Intel x86_64 chipsets.

I've noticed that VMs created on the newest node refuse to migrate to the others:

[root@hachi ~]# prlctl migrate pavel lindell
WARNING: You are using a deprecated CLI component that won't be installed by default in the next major release. Please use virsh instead
Migrate the VM pavel on lindell  ()
Operation progress    100%
Operation progress ... 0%
Failed to migrate the VM: Operation failed. Failed to execute the operation. (Details: operation failed: guest CPU doesn't match specification: missing features: fma,movbe,bmi1,avx2,bmi2,invpcid,mpx,rdseed,adx,smap,clflushopt,pku,arch-capabilities,xsavec,xgetbv1,pdpe1gb,abm,3dnowprefetch)
[root@hachi ~]#

But VMs created on the other nodes will migrate perfectly well to the newer node - and back.

So, one solution would be to always create VMs on the oldest host, so they can be migrated to any other. But that's no help for the existing VMs.

There is absolutely no additional CPU feature on the newest node which is critical to any VM, which begs the question:

Is there a configuration file for each VM that could be modified to set a certain "least common denominator" CPU feature set (i.e., to make it appear as though the VM was created on the host with the oldest CPU) and thus enable migration between them all?