Putting out a fire in a data center is no small feat. In February, the Bas-Rhin firefighters published feedback following their intervention in the fire at the Strasbourg data center of OVHcloud in March 2021.
The fire, which caused the destruction of most of the building and the equipment installed by OVHcloud, did not cause any casualties, but caused disruptions and data loss for the host’s customers.
In their feedback, the firefighters discuss their intervention and the main difficulties encountered by their teams in extinguishing the fire.
No power cut device
Called shortly after midnight, the firefighters arrived on site a few minutes later and found that the fire had started on the ground floor of the SBG2 building, in an “energy” room comprising an inverter and a high voltage transformer. . The site’s on-call personnel have already been evacuated. They also face electric arcs around the entrance door to the building “and sharp lightning cracks with a deafening noise”.
Firefighters seek to cut the power to limit the risks and use their fire hose to extinguish the flames. But they discover that the building is not equipped with a device to cut off the current of the building, a “choice of economic strategy on the part of the company”, will indicate the writers of the document. For a data center, maintaining the power supply is a priority.
To cut the power, the firefighters will therefore have to turn to Electricité de Strasbourg in order to cut off the power to the building from the outside, which will only be possible from 3:28 a.m. “At this time, current is still present in the inverters,” note the firefighters. Similarly, the building does not have an automatic fire extinguishing system to fight the fire as soon as it is detected.
“Chimneys of Fire”
The other point underlined by the report relates to the very architecture of the datacenter: the design of the SBG2 building is designed to promote cooling of the servers by creating a permanent air current.
Unfortunately, in the event of a fire, this architecture favors the action of the flames and the firefighters thus indicate that the two interior courtyards of the building acted as “fire chimneys”. Finally, the “Energy” room has an intumescent wooden ceiling (that is to say, which warps under the effect of heat) fireproof 1 hour.
Among the concerns dismissed by the firefighters, the release of smoke from the data center is not considered worrying following the first readings. In the same way, the movements of the building subjected to heat are attributed to the dressing of the latter and not to the load-bearing elements. Cooling the metal from the outside helps prevent collapse.
Data centers are not “risk establishments”
In the same way, the authors of the report indicate that the on-call technicians present on the scene at the time of the fire know the scene well and are able to give the firefighters precise and reliable information.
Finally, the firefighters’ report notes that data centers are not classified as “establishments at risk” under the ICPE legislation, regulations which govern industrial and agricultural risks and which allow firefighters to take the necessary measures before intervening on this type. of site.
We sent several questions to OVHcloud in order to have explanations on the various points raised in the report, but we did not receive a response.