Comment Regexs..... (Score 1) 377
I missed one character in a regex in a monitoring system that would cause it to think all the hard drives in a machine had failed when the machine was booted. Since it only happens on boot, it wasn't noticed until there was maintenance work that powered off an entire datacenter. When they turned the power back on, ~5000 machines all decided their hard drives had failed simultaneously. Took 2 days to clean up the mess.