Hi,

I upgraded a guest from Devuan Jessie to Devuan Ascii.

The guest wouldn't boot the 4.9 kernel, but I could boot it's older
3.16 kernel okay.

Then I upgraded the host from Jessie to Ascii as well and all was good.

My son believes this is a bug, but I'm inclined to believe that this
is a "fair" failure as whatever the host presented to the guest wasn't
compatible enough in relation to the kernels (probably).

If I upgraded the host first, then I probably wouldn't have seen any
issues.

NB: I am not using qemu directly, only via virsh. Perhaps if using
qemu directly it would be different.

Am I right in this case, or is my son right?

In any case, if my son is right, then there is a bug, but it wouldn't
hurt to always upgrade the host before any guests that rely upon that
host.

Kind Regards
AndrewM