Inert Gas Data Center Fire Protection can damage hard disks


Working for a local government in the Netherlands, an inert gas fire exthuingishing cause massive damage to our storage system .

(See: Can you send me 56 spare Netapp disks in a few hours?)

After a disaster caused by a faulty fire extinguishing system inevitable the insurance company started to ask questions.

How can disk become defective by inert gas?

After some investigation we discovered the problem is not uncommon, There were more reports Inert Gas Fire Suppression causing havoc on drives. The problem has nothing to with pressure, temperature or chemical reactions.

 

The real problem is acoustic noise!

 When the gas is released from the pressurized cylinders it moves through the pipes at very high velocity. On exit through multiple nozzles in the data centre, it generates high-level acoustic noise. The noise reaches

the HDDs where it causes vibration, which in turn causes the read/write element to go off the data track.

About Inert Gas Fire Suppression Systems

The Inert Gas Fire Suppression System is comprised of Argon (Ar) or Nitrogen (N) gas or a blend of those gases. These gases present no danger to electronics, hardware or human occupants. The systems extinguish a fire by quickly flooding the area to be protected and effectively diluting the oxygen level to about 13–15%. Combustion requires at least 16% oxygen. The reduced oxygen level is still sufficient for personnel to function and safely evacuate the area. Since

their debut in the mid-1990s, these systems have proven to be safe for information technology equipment application.

The systems store the inert gas blends in high-pressure cylinders that can be connected in parallel. Depending on the manufacturer, cylinder pressure ranges from 2,200–2,900 pounds per square inch (PSI), or 152–200 bar, and discharge at pressures of 870–1,000 PSI (60–69 bar). Because of the sudden addition of inert gas within the protected area,

automatic venting is a component of the design to prevent pressure build-up.

ING Bank datacentre in Romania shut down for 10 hours after a fire extinguishing test

 ING Romania did a fire extinguishing test in the Bucharest datacentre on Saturday September 10 2016.  Staff of ING opened the cylinders to dump the  inert gas into the datacentre. However the noise of the gas dump was at such level that the vibration damaged many hard drives resulting in server being unavailable.

The bank monitored the sound and it was very loud, a source familiar with the system told us. “It was as high as their equipment could monitor, over 130dB”.

Acoustic Nozzle Design for Fire Protection Application

Design is an important factor to mitigate against risks of acoustic damage by inert gas fire extinguishing.

An interesting paper about the matter can be found here at the National Fire Protection Association (Massachusetts).

More reading on this matter

 

Siemens White Paper: Potential problems with computer hard disks when fire extinguishing systems are released

Provider WestHost was down for 6 days when a fire-suppression system  test went terribly wrong

Was it caused by the inert accoustics, or by the the fire alarm siren (horn)?

 

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