Science could make fire suppression safe
Data centers have had a problem with fire suppression systems. While trying to remove the threat of fire damage, they have actually introduced dangers of their own.
These systems operate by flooding the data center with inert gas, preventing fire from taking hold. However, to do this, they have to fill the space quickly, and this rapid expansion can create a shockwave, with vibrations that can damage the hard drives in the facility’s storage systems.
Image from: greenhousedata.com
A year ago, this happened in Glasgow, where a fire suppression system took out the local government’s email systems. And in September ING Bank in Romania was taken offline by a similar system. At the bank, there wasn’t even a fire. The system wrecked hard drives during a planned test of the fire suppressions system - one which had been unwisely scheduled for a busy lunchtime period.
These are just the incidents we know about. Ed Ansett of i3 has told us that this same problem has occurred on many occasions, but the data centers affected have chosen not to share the information.
It’s also likely these faults will happen more frequently as time passes because hard drives are evolving. To make higher capacity drives, vendors are allowing read/write heads to fly closer to the platters. This means they can resolve smaller magnetic domains, and more bits can fit on a disk. These drives have a smaller tolerance to shaking.
This is a shame because information leads to understanding, which is the key to solving the problem. To solve the problem, we need a scientific examination of how these incidents occur. And it turns out this is exactly what has been happening.
At DCD’s Zettastructure event in London last week, I heard about two very promising lines of inquiry that could make this problem simply disappear.
Fire suppression vendor Tyco believes that with drives becoming more fragile, more gentle nozzles are needed. The company has created a nozzle which will not shake drives, and will eventually be available as an upgrade to existing systems. Product manager Miguel Coll told me that the new nozzle is just as effective in suppressing fires, but does not produce a damaging shockwave.
That sounds like a problem solved - but there’s another approach. Future Facilities is well known for its computational fluid dynamics (CFD) software, which models the flow of air in data centers and is usually used to ensure that hot air is removed efficiently and eddies don’t waste energy.
Future Facilities checked the physics and found its software could also model the flow of much faster air, including the shockwave produced when a fire suppression system floods the room with gas.
The company modeled the operation of the systems and found that the nozzles are usually placed too close to IT systems. The rules by which they are placed were set by authorities outside the data center industry and predate today’s IT systems.
Future Facilities product manager David King reckons the research means that the whole problem can be avoided by simply placing the nozzles according to CFD models of how they work.
The data center industry’s weapon in the war on risk and waste is science. I’ll publish more about this on DatacenterDynamics, while the agenda of the Zettastructure event is online and the presentations will be available.
Peter Judge is editor of DatacenterDynamics