Kernel panic after migration from Intel <> AMD

[janw]

Hello,

after a live migration from AMD to Intel or Intel to AMD the VM is going into a kernel panic.

We're using the following nodes inside our cluster:
Intel nodes:
Dual Intel Xeon E5-2680v2 with 256 GB RAM
Dual Intel Xeon E5-2650v4 with 512 GB RAM
New AMD node:
AMD EPYC 7402P

All nodes running the latest stable version. Output of pversion -v

proxmox-ve: 6.1-2 (running kernel: 5.3.18-2-pve)
pve-manager: 6.1-8 (running version: 6.1-8/806edfe1)
pve-kernel-helper: 6.1-7
pve-kernel-5.3: 6.1-5
pve-kernel-5.0: 6.0-11
pve-kernel-5.3.18-2-pve: 5.3.18-2
pve-kernel-5.3.18-1-pve: 5.3.18-1
pve-kernel-5.0.21-5-pve: 5.0.21-10
ceph: 14.2.8-pve1
ceph-fuse: 14.2.8-pve1
corosync: 3.0.3-pve1
criu: 3.11-3
glusterfs-client: 5.5-3
ifupdown: 0.8.35+pve1
ksmtuned: 4.20150325+b1
libjs-extjs: 6.0.1-10
libknet1: 1.15-pve1
libpve-access-control: 6.0-6
libpve-apiclient-perl: 3.0-3
libpve-common-perl: 6.0-17
libpve-guest-common-perl: 3.0-5
libpve-http-server-perl: 3.0-5
libpve-storage-perl: 6.1-5
libqb0: 1.0.5-1
libspice-server1: 0.14.2-4~pve6+1
lvm2: 2.03.02-pve4
lxc-pve: 3.2.1-1
lxcfs: 3.0.3-pve60
novnc-pve: 1.1.0-1
proxmox-mini-journalreader: 1.1-1
proxmox-widget-toolkit: 2.1-3
pve-cluster: 6.1-4
pve-container: 3.0-22
pve-docs: 6.1-6
pve-edk2-firmware: 2.20200229-1
pve-firewall: 4.0-10
pve-firmware: 3.0-6
pve-ha-manager: 3.0-9
pve-i18n: 2.0-4
pve-qemu-kvm: 4.1.1-4
pve-xtermjs: 4.3.0-1
qemu-server: 6.1-7
smartmontools: 7.1-pve2
spiceterm: 3.1-1
vncterm: 1.6-1
zfsutils-linux: 0.8.3-pve1

I've already tried swiching the configured processor type without any change. The VM is still going to kernel panic after the migration.

Does anyone have tips for me?

Thanks.

 

[joshin]

What's the underlying OS, and what processor settings do you have for the VM?

I've found that it's best to power down and restart a VM when going from AMD <-> Intel.

 

[janw]

I‘m using Debian 10 on all nodes. The processor type of the VM is set to kvm64 but I‘ve already tried other types as well.

 

[LnxBil]

I've found that it's best to power down and restart a VM when going from AMD <-> Intel.

Yes, everything else resulted in crashes and problems.

after a live migration from AMD to Intel or Intel to AMD the VM is going into a kernel panic.

Don't do something like this. It may work from one Intel to another Intel Generation, but best do have a homogeneous cluster. A lot of problems magically disappear if you just do that. CPU should be the same generation with the same features. You can also have problems with time calibration if the speed does not match.

 

[mir]

[..] but best do have a homogeneous cluster. A lot of problems magically disappear if you just do that. CPU should be the same generation with the same features. You can also have problems with time calibration if the speed does not match.

There is a reason why running different CPU models and generations is unsupported and uncertified on VmWare as well!

 

[LnxBil]

There is a reason why running different CPU models and generations is unsupported and uncertified on VmWare as well!

I tried to find a statement in the PVE docs, but could surprisingly not find any mention of the problems that arise from non-homogeneous clusters.