the first and perhaps less interesting circumstance is, opening certain documents causes libreoffice (and all it's doc windows) to hang (fail to render or expose) for several minutes, but all other processes are uninhibited. is there anything short of diving in with gdb that might show me something interesting about where it's stuck? the second, more rare and more disturbing circumstance is, i get hangs from time to time, eg sometimes a whole minute or longer where new processes won't launch but existing processes proceed as if the system was idle. htop is a nice start. i can imagine a tool that could tell me i have this much activity on this ether channel and that much on that ether channel, this much disc activity on this disc channel and that much on that disc channel, this process has done this much i/o on this channel over the last nn seconds, that process has been blocked for nn seconds waiting for .... anything like that out there? what tools are available that might show me something relevant?