I'm just saying these things can quickly get more complicated than expected. I too had extinguishers handy at the time but of course I didn't know what to use them on (and neither did the FD for three hours). These electrical fires can be tricky to debug, especially when different kinds of barriers come into play.
> But it's pretty clear this wasn't a "real" datacenter by their lack of protocols for handling fire, it was some office server thing.
Probably. What's the right protocol though? In this case, it was apparently clear that something minor was amiss, nothing that would justify shutting down the whole thing. In any case, flooding the room with inert gas would probably not have made much of a difference, as it looks like the battery was never actually burning.
House construction is insane, anyway -- they're full of random stuff, and there are plenty of non-accessible void spaces. Datacenters are at least generally nice and open, so finding a weird residential hidden fire should be a lot easier. (which is why datacenters get permission to run their wiring the way they do, etc., because they have so much other safety)
The right thing to do in a real datacenter it to check which of your ~hundreds of laser VESDA sensors first tripped, and investigate in that area :) Presumably you have floor air supply, ceiling air return, so the first thing to trip should be a ceiling sensor near your fire. If no floor sensors trip, I wouldn't be super afraid to go in there, and if it's only a small number of them it's not a big fire.
You don't want the dry pipe to go off for sure, and you don't want the FM-200 either, but the consoles should be reporting the smoke alarm to you way before a human would smell it "filling the whole room", and they don't generally discharge either for very small events (at least everywhere I've seen).
In an office (some open plan, some cubicles, some conference rooms and offices, etc.), with a few racks of equipment, and maybe some lab space, it's a lot more similar to the scary hidden residential fire problem. :( Your risks in trying to uncover the problem are actually higher than in the datacenter because then you don't have the amazing gas system and a dry pipe backup to save you if it turns into a big fire while you're there, and it's not as designed for easy egress, and probably doesn't even have real EPO. I wonder if there's a firefighter on HN who would know the real answer to this case.
FM200 systems do go off for small events at times. I managed a team of datacenter facility specialists up until last year, and we'd seen issues like: FM200 dumps because underfloor smoke detectors notice smoke from a CRAC condensate pump (pretty low risk) smoking its winding, FM200 dumps when a quick refrigerant discharge (technician error) looks like smoke to the detector, and false positives at smoke heads due to a dirty area under the raised floor, combined with air flow irregularities.
I definitely agree that I'd be more concerned about a house fire, but the rule that we enforced to our people and the vendors, as well as the vendors working for us (not to mention the guidance that we received from our customers) was that nothing in that datacenter is worth potentially losing anyone's life. That having been said, I have Toucan Sam'd in a datacenter to try and find the source of an odd odor before, but never alone, and only to find out what to secure power to. I wouldn't sit there and try to fight it with a fire extinguisher.
The only "accidental discharges" I've seen were related to construction dust in an underfloor. And yes, suck :(
In general the purpose of a handheld extinguisher is to fight tiny fires as well as to help you escape a bigger fire. The thing I'd be most afraid of would be someone walking around trying to find a small fire, only to discover a big fire, have egress blocked, and need to figure out a solution. Or, coming across an actual person who is on fire or otherwise in danger (even if you'd expect virtually no personal risk for property, I think most people would accept substantial personal risk to save a person, particularly a coworker).
> But it's pretty clear this wasn't a "real" datacenter by their lack of protocols for handling fire, it was some office server thing.
Probably. What's the right protocol though? In this case, it was apparently clear that something minor was amiss, nothing that would justify shutting down the whole thing. In any case, flooding the room with inert gas would probably not have made much of a difference, as it looks like the battery was never actually burning.