I bought a used 6TB WD Purple drive with around 29,000 hours on it for a new NVR system. It worked quietly for about a month, but now it makes a strange chirping sound whenever the drive gets close to full. After reformatting it, the noise stopped completely. The drive is installed in the NVR, so I cannot easily run a fresh SMART report without removing it and temporarily installing it in another computer. The original SMART report from the seller showed no obvious problems. I am testing whether shortening the overwrite period changes the behavior, but I would like to know whether this sounds like a failing drive, a problem writing near the end of the disk, or something related to the NVR's overwrite process.
2 Answers
The fact that reformatting temporarily made it quiet does not necessarily mean the drive is fixed. It may simply have stopped writing to the problematic area until the NVR fills it again. SMART data would be useful, particularly pending sectors, reallocated sectors, offline uncorrectable sectors, and reported uncorrectable errors. Since the drive is in an NVR, reducing the overwrite window is a reasonable quick test, but it should not replace a proper diagnostic.
That pattern often points to a weak or bad sector near the end of the disk. When the NVR reaches that area, the heads may repeatedly retry the write or reset, which can produce a chirping or clicking-like sound. A drive can pass an older SMART check and still develop problems later, especially with nearly 29,000 hours on it. Back up anything important and test the drive with a current SMART report or full surface scan as soon as possible.
If the noise returns only after the system starts using the later part of the disk, that would strengthen the case for damage or unreadable sectors near the end rather than a normal overwrite sound.