How long do NAS drives last?

No drive has a guaranteed lifespan, but NAS drives are engineered for continuous, multi-year operation, and in practice many run reliably for three to five years or more. The honest framing is statistical: some drives fail early, most last years, a few last a very long time.

What MTBF actually means

Manufacturers quote figures like 1 million hours MTBF (mean time between failures). That is not a promise your drive lasts a million hours (over 100 years); it is a fleet-average failure rate across many drives. Useful for comparing classes of drive, useless for predicting one specific drive.

What actually shortens life

• Sustained high temperature.
• Very heavy workload beyond the drive's rating.
• Vibration in a poorly-damped chassis.
• Power quality and frequent unclean shutdowns.

How to manage it

Do not replace drives on a calendar; replace on evidence. Enable SMART monitoring and scheduled extended tests, watch Reallocated and Current Pending Sector counts, and act when the trend turns bad. Keep drives cool and backed up. Because RAID protects against a single failure, staggering drive purchases (so they do not all age identically) is a smart hedge.

When a drive does show its age, replace it with a same-or-larger CMR NAS drive; the table lists current options.