MTTR
also: Mean Time To Repair, Mean Time To Recovery, MTTR metric
MTTR (Mean Time To Repair) is the average time required to detect, diagnose, and fix a system failure or incident back to operational status.
MTTR measures how quickly a system can be restored after an outage or failure occurs. It's a key reliability metric in system administration and DevOps, calculated by dividing total downtime by the number of incidents: MTTR = Total Downtime / Number of Incidents.
For example, if a web server experiences 3 failures in a month with total repair times of 2 hours, 1.5 hours, and 30 minutes, the MTTR would be 1 hour 20 minutes. Lower MTTR values indicate faster incident response and better system reliability.
In practice, Linux administrators track MTTR to identify bottlenecks—whether delays stem from detection lag, troubleshooting complexity, or access to fix systems—and use this data to implement monitoring, automation, and runbooks that reduce recovery time.