On Firmware, A Thousand Servers at a Time

Updating server firmware at scale. (Page 136)

Uninterruptible power supply

The device that carries the IT load through the instant utility power fails. (Page 16)

UPS and Battery State Prediction

Estimating battery state of charge, available runtime, and capacity fade using electrochemical models and recursive filtering. (Page 126)

Uptime Institute tier classification

The Tier I–IV scale that grades a facility's redundancy and maintainability. (Page 6)

Where the Grid Comes In

Where grid power physically enters the facility. (Page 35)