Oh… Apparently this afflicted 7.3-RELEASE for a short while, then was corrected in 7.3-STABLE. So I’m not sure what problem I was encountering below. The consensus now is I was hitting MAXCPU. But I should have hit that on 7.2.
I upgraded a VM to FreeBSD 7.3 from 7.2 and now it won’t boot. It stops probing at MDT: Found CPU APIC ID 15 ACPI ID 15: disabled. Tried booting in single user, and in safe mode, and with ACPI disabled.. none boot. I may go back to my snapshot and run that, this time, go from 7.2 straight to 8.1 and see how that goes. If not, I’ll stay on 7.2.
Since I wrote that, I found out there’s a bug in 7.3, which doesn’t like that many CPUs. How many it likes, I don’t know for sure, but I’m told anything more than 12 is not fun.
I did manage to get the VM back by booting off kernel.old.
FYI, I’m pretty sure the host system is running KVM.
I am now building 8.1-STABLE and will move to that directly. 7.3 was going to be a stepping stone.