How to repair a bad sector and bring external HD back on line

[roninnewyork]

My external USB hard drive is off line. Here's the message I see in the Event Viewer:

A corruption was discovered in the file system structure on volume F:.

A bad cluster was discovered while accessing file data. The file reference number is 0x2000000000002. The name of the file is "<unable to determine file name>". The extent containing the bad cluster is located at Vcn 0x39b9, Lcn 0x17378.

A previous message said to use CHKDSK to repair the bad cluster.

I would but I cannot bring the volume on line.

Is there anything I can do besides a funeral?

RON

 

[Lutfij]

See if TestDisk helps resolve anything on your drive. Other than that, it's either to a professional data recovery shop or a funeral.

 

[USAFRet]

Is there anything I can do besides a funeral?

Send it back for a warranty replacement.
If not under warranty, fridge magnet donor.

 

[roninnewyork]

I rebooted the machine and the HD came back on line. BUT there are problems. And now Access is Denied. I was trying to back up recent stuff to an external flash drive.

 

[roninnewyork]

Luckily I have a backup device which was fairly up to date. I managed to copy over my recent files (Visual Studio projects) and some other stuff. I'm getting new HD shortly. I sort of "fixed the HD" with chkdsk /rfx (or chkdsk /r /f /x). Now there are no HD-related errors in the Event logs. I wish I could find out the root cause. I assume the new HD should be solid state as no moving parts is better, correct?

 

[Solandri]

CHKDSK does not repair bad sectors. All it does is confirm that the sector has gone bad (by repeatedly trying to write/read data on it), then instructs the hard drive to substitute a reserve sector in its place. From that point on, any time the computer requests that sector from the HDD, the HDD instead uses the reserve sector that's been mapped into its place. In other words, the drive hasn't been fixed, the problem has only been covered up.

Sectors do occasionally go bad due to age. That's why HDDs have reserve sectors. If this is what happened, then you are fine. However, there's a chance the sector went bad due to other reasons. Maybe the drive's bearing is going and the drive is having trouble aligning the read/write heads properly to the data tracks. Maybe a speck of dust got in or worse yet some of the platter material flaked off and is now bouncing around inside as the drive spins, literally scraping more data off the drive.

So treat the drive as suspect. Check the SMART status (use CrystalDiskInfo or the drive manufacturer's diagnostic program). Given the large number of problems you're reporting, I wouldn't trust the drive with production work like Visual Studio. I would order the new HDD ASAP and just restore everything to that. Demote the current drive to an internal backup/data drive while you check its SMART status every few days for a few weeks. If it reports the drive is healthy during this time, then continue to use it as a second HDD. If it reports any problems at all, RMA it or trash it.