One of my serious irritations with ZFS is how various ZFS commands (orat least sub-commands of zpool ) will stall badly if it can't talk tosome of the underlying disk devices. This is especially apparent whenyou're using iSCSI; for example, I accidentally booted a system with theiSCSI cable plugged into the wrong port, and once the system had booted zpool list simply hung.

(Worse, it hung uninterruptibly; I could not stop it with ^C, use jobcontrol to background

One of the things that would be useful in an access tracer is reporting not just what was accessed, butwhere it was accessed from. A basic starter for this is knowing whatfunction called you.

CPython has enough introspection faculties to give youthis information, but it's not entirely documented how todig it out. The big tool for this is the inspect module , and wecan use it to define a function:

import inspect

def getcallerinfo():    fr = inspect.currentframe()    try:         fr