TS3400D - Keeps inform disk has bad sector

[cthinh]

Since I enable the notification on my NAS TeraStation T3400D, everyday I receive an email from the box saying one of my drive has problem with bad sector found:

[Notice] TeraStation Status:Drive Status
Drive 1  [Normal]:No errors occurred.
Drive 2  [Notice]:Bad sectors have been detected.
Drive 3  [Normal]:No errors occurred.
Drive 4  [Normal]:No errors occurred.
......
[Drive Error Status]
Drive 1: 0
Drive 2: 0
Drive 3: 0
Drive 4: 0

 I am not sure about this error because I have turned off the NAS, pulled out the drive and used other software to scan the HD (WD Data LifeGuard for Windows, EaseUS Partition, Windows disk check,..) but none of the above software found an error on the disk. All the LED lights on the NAS are green and the NAS still performs as normal but it is still very annoyed.

The NAS box is using firmware version 1.82-01. Has anyone here met before? Is it a bug?

[Texturtle]

This error means that either 1) The drive's own SMART interface is reporting bad sectors or 2) the TS encountered a read/write error. Try a utility that directly reads the SMART info. A drive can have multiple bad sectors that have been remapped internally and still report as good with some software. A utility that reads the SMART info can tell you exactly how many sectors have been remapped. In any case, it's probably not a bad idea to replace the drive.