power-on-hours · shipping · also POH, accumulated power-on time

Power-on hours

Power-on hours is accumulated powered-operation time reported for a device, interpreted according to that device's counter and interface semantics.

Related Observatory article: Power-on hours on hesela.com

This is not time since purchase, host uptime or a measure of write endurance. A self-test timestamp records an earlier test, not necessarily current runtime. Raw time fields may use units other than hours; missing telemetry is unknown, not zero. [2] Cisco's affected-drive procedure requires fresh collection and distinguishes accumulated minutes from hours. [1]

Relations

related

drive-firmware-revision, smart, smart-raw-value, drive-day

Citations

1. Cisco FN70545, revision 2.0: 40,000-hour failure, C405 firmware and runtime collection (accessed 2026-10-16)
2. smartmontools 7.5 smartctl manual: self-test timestamps, background-scan runtime and raw time formats (accessed 2026-10-16)

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