Comment 22 for bug 1500739

Next time this happens, please check the ilo for a massive backlog of nbd kernel messages. I suspect it's nbd's insane logging rate (tens of thousands of lines per second) endlessly growing the serial console backlog. "dmesg -D" appears to be a quick way to fix machines in this state, or prevent it from ever happening. There is probably a more elegant solution (such as, get the nbd module to calm down)