Uptime
Definition
The percentage of time a data center’s systems remain operational without interruption. A ‘four nines’ uptime goal (99.99%) allows less than 53 minutes of downtime per year (0.01% of the year’s 525,600 minutes). Achieving high uptime requires redundant power systems, backup generators, multiple internet connections, and 24/7 staffing—all factors that affect employment and infrastructure requirements.