Which of the following BEST describes the metric that is used to measure server downtime?

MTTR (Mean Time To Repair or Mean Time To Restore) is a crucial reliability metric that calculates the average time required to diagnose and fix a failed system or component and return it to full operational status. It directly measures the duration of an outage, making it the best descriptor for server downtime.

BIA (Business Impact Analysis) is a process used to evaluate the potential effects of an interruption to critical business functions, not a direct metric for measuring downtime duration.

RPO (Recovery Point Objective) defines the maximum acceptable amount of data loss in terms of time during a disaster, not the actual duration of the system downtime.

SLA (Service Level Agreement) is a contractual agreement that specifies the level of service expected from a provider, which may include uptime guarantees, but it is not a direct metric used to measure downtime itself.