I have a Seagate 8TB external hard drive connected to my NAS, and since yesterday it has been making a continuous clicking sound. I initially thought it might be indexing because I had recently copied a folder containing more than 100,000 files, but the clicking continued even after I deleted that folder. When I access the server, the drive briefly makes its usual lower-pitched, louder, longer activity sounds, then the clicking disappears for 5–10 seconds before returning.
A short SMART test reports no problems, and the operating system still shows the drive as healthy after roughly 20,000 hours of use. I also ran `iostat -xd sdb 2`, which showed zero activity even while the clicking was audible. The drive is running in the mid-50s °C because of the constant noise and the roughly 28°C room temperature.
Could this still be a mechanical failure despite the clean SMART results and lack of reported disk activity? Should I stop using it, run the full 12–14-hour SMART test, or focus on copying my important data elsewhere first? I'm also interested in inexpensive but reasonably secure off-site backup options.
3 Answers
A repeated click can indicate the heads are repeatedly seeking, recalibrating, or failing to read a particular area of the disk. It may not sound exactly like the classic repeated startup-and-shutdown failure, but the practical advice is the same: assume the drive could die at any time and do not rely on a clean short SMART test as proof that it is safe.
Treat the clicking as a possible mechanical failure and back up anything important immediately. SMART and operating-system health indicators can remain normal even when a drive is beginning to fail, so they should not outweigh a new, persistent clicking sound. Avoid unnecessary testing or continued use until the data is safe, then replace the drive.
The temperature is also higher than ideal for continuous NAS use, especially in a warm room. However, heat alone does not explain away a new clicking noise. If the data is backed up, you can run the extended SMART test for additional information, but I would not run it before securing the data because a full test puts extra stress on a questionable drive.
I disconnected and removed the mount from the NAS, but the clicking continued even with no reported disk activity. I’ve started copying the important data to cloud storage, since it’s better to do that now than wait for the drive to stop responding completely.