Google Cloud: 3 ms voltage drop triggers a 15-hour outage
On July 15, 2026, Google Cloud experienced a data center outage affecting VMware Engine, Bare Metal Solution, and Google Cloud NetApp Volumes in the europe-west4-a zone in the Netherlands. A three-millisecond voltage drop affected both utility power feeds. Protective breakers tripped and initiated transfers to Diesel Rotary Uninterruptible Power Supply systems, known as DRUPS. Feed B transferred successfully. Feed A’s DRUPS failed because of electrical component failures, reducing power redundancy. An automatic transfer moved three affected rows toward feed B. Rows 1 and 2 transferred successfully, while Row 3 tripped an overload-protection breaker and lost power. The voltage disturbance also knocked a chiller controller offline. Distribution pumps failed to restart, and redundant cooling was unavailable because of ongoing construction. Data hall temperatures reached 44°C. Google shut down servers, storage clusters, network switches, and customer workloads to protect hardware and customer data. The combined customer-impact window lasted 14 hours and 55 minutes.
Google Cloud
