[c-nsp] Sup720 hang while writing SP crashinfo?

[Kevin Graham]

We had a Sup720B (non-redundant, running modular SXI) crash, due to what looks
like was due to a CPU_MONITOR watchdog event. What was nasty though was that
rather than reload, it hung (dead and unresponsive console) and required a
power cycle.

The RP crashinfo made it out fine, however SP crashinfo was incomplete. Looking
at that, its due to sup-bootflash running out of space (1 byte left w/ an
incomplete/inaccessible crashinfo).

Unfounded speculation is that the "hung" state was due to system pounding away
trying to finish writing crashinfo to a full filesystem.

Is that hypothesis at all reasonable, or is there something else that should be
explored?