Probably nothing, might be satisfying a regulation (like that second ground rod).What's a fire sprinkler doing in data room.
Yes, and....Electrical fires should not be doused with water . . . .not even with wet chemicals.
Most common is CO2 to displace oxygen.
I don't think the OP, or the rest of us, have been talking about an engineered "data room"; more like a closet where someone stuffed a comm cabinet.
That's being polite about it (same goes for the contents of an old hot-water heating system).but the first few seconds to half a minute are something rare and special