Ukraine says Russian drones are hitting data centres, and the power and cooling chain is the target

Russia's defence ministry confirmed it struck the Datagroup site and said the facility was used by Ukrainian military intelligence, according to the BBC. The same report says a separate attack killed a 14-year-old boy, whom Israel's foreign ministry identified as an Israeli citizen.

The numbers around the strike show how quickly a data centre outage becomes a civilian problem. Roughly 100,000 households in Kyiv and the surrounding region lost internet on Wednesday because of strikes, the BBC reported. In Lutsk, in north-western Ukraine, electronic information boards at public transport stops stopped working on Friday. The city council blamed damage from a Russian attack on data centres in Kyiv. Kyiv Mayor Vitaliy Klitschko said on Friday evening that seven people had been killed and 59 injured in overnight attacks.

Why a data centre is a hard target to replace

A data centre is not a building full of servers that can simply be unplugged and moved. It is a chain of electrical and thermal systems that must run without a gap. Utility power enters at medium voltage, commonly 11 to 33 kV in Europe, and is stepped down through transformers and switchgear before reaching the racks, according to datacenterplaybook.com. Generators handle long outages but take seconds to start. The UPS covers those seconds. Neither works alone.

Cooling is the other half of the same problem. Every watt a server draws becomes a watt of heat, and that heat has to leave the building. Air cooling, chilled water, direct liquid cooling and immersion systems are the main options, according to a caeled.com technical guide. The same guide puts cooling at 30 to 40 percent of a data centre's total power use, though efficient designs can push that towards 25 percent. Uptime Institute data cited by phoenixNAP found cooling problems caused 19 percent of all data centre outages over the last three years.

Backup sites and decentralised networks

Datagroup said its specialists were assessing damage after the daytime attack but that all services "continue to operate from backup sites", the BBC reported. That is the redundancy model working as designed: dual power paths, backup generators and failover to other facilities. Some firms have already begun moving data from damaged servers to facilities abroad, according to the same report.

Serhii Beskrestnov, Zelensky's top adviser on defence technologies, admitted on Thursday that "there may be local disruptions" and that the cost of internet services could rise to cover repairs. But he stressed that Ukraine's internet network is highly decentralised, so the country "will not be left without internet access".

"Rapid alerts about missile and drone threats are essential - they save lives. This is critical civilian infrastructure... It is not a military target. It is essential to keeping everyday life functioning," Foreign Minister Andrii Sybiha said, according to the BBC.

Russia's defence ministry also said that over the past few days its forces targeted data processing and telecommunications centres including New-Telco, United DC, Kyivstar and Parkovyi, the BBC reported. Moscow has also intensified strikes on Ukraine's energy and railway infrastructure as winter approaches.

The physical layout of a facility matters here. Hot aisle and cold aisle containment stop exhaust air mixing with intake air, raised floors improve under-floor pressure distribution, and cable management keeps airflow clear, according to caeled.com. A misaligned containment design in a Guangdong project produced constant thermal alarms until the airflow was redesigned, the same source says, after which energy bills dropped 18 percent. Those are the details that decide whether a damaged site can keep running on partial capacity.

European officials have framed the wider campaign as hybrid warfare. Poland's prosecutors opened an investigation into an arson attack on a Starlink satellite station in Wola Krobowska on Wednesday, saying there was a reasonable suspicion the perpetrators acted on orders from Russian special services, according to the BBC. The station routes internet traffic through Poland to countries including Ukraine. The EU also agreed on Friday to release 6.6bn euros for Ukraine, including 900 million euros for its Military Assistance Mission and a 1bn euro fund for joint procurement of equipment, the bloc's top diplomat Kaja Kallas said.