On Mon, Jan 30, 2017 at 5:48 PM, Dan Norton <dnorton@mindspring.com> wrote:
After a freeze, I find that pkill will cause output to crash.dmp and the latest is attached.

That looks benign.

How about attaching strace when frozen? 

sudo strace -p <pid>

This should log all system calls the VM is still doing. Then press alt-. and see if the VM processes that.

And if all else fails, you may have to whip out gdb to see what exactly is going on.

- Bert -