Mysterious Lockups

Of all computer problems, the unresponsive hang is the most annoying and most difficult to trace. There's no crash, no panic: everything just stops dead. The keyboard is useless, telnets just time out - you have no choice but to power cycle the machine. Well, maybe. If you are running Linux, and if you have scodb gives access to a kernel debugger if available. I don't know of anything like that for Mac OS X; there is sar. A build up of unusual system activity prior to the hang might give clues as to its cause. If the hangs repeat, setting a "ps" running to log activity can help zero in on that should it happen again. After all that though, these things are almost (*almost*) always hardware, and more often than not it is power related: bad power supplies are the most common cause I've seen. After that comes disk controllers and then motherboards, but nowadays I don't feel it's worth spending a lot of time chasing this sort of thing: move the system to new hardware as quickly as possible. If you then want to spend time investigating possibilities on the old hardware, at least you won't be interfering with normal business. However, given the cost of hardware vs. the cost of labor, even that may not make sense: accept that the whole thing was mysterious, do whatever you need to do to protect any confidential data, and move on. Maybe some parts can be recycled or maybe the machine can move down to less important use, but the cost of messing around with it in its original role just doesn't make sense. Add to Del.icio.us | Digg | Reddit | Furl Bookmark Murdok: