Why does CHKDSK report no problems after a disk read error?

windows windows-8 chkdsk

8,050

Solution 1

Unfortunately this is a bug that affects Windows 8, Windows 8.1, Server 2012 and Server 2012 R2. CHKDSK under those OS is unable to populate the hidden $BadClus file, which contains a list of the defective sectors found in the disk.

If you run CHKDSK under Windows 7 it will work correctly, and it will mark those clusters as bad in the $BadClus file.

Let's hope Microsoft fixes this bug for Windows 10!

Solution 2

Probably just in case you are running it before Windows starts - if it failed, Windows wouldn't boot.

Also, technically, the file system is ok, it's just that one file that has an issue. Windows probably marked that sector as bad, and that file likely now has missing data.

You should really replace this drive.

8,050

Michael Cook

I am a Father of 2, a NodeJS/RectJS developer with over 20 years experience, a photography enthusiast and questionable guitar player.

Updated on September 18, 2022

Comments

Michael Cook over 1 year
Recently, when copying files from one drive to another I noticed one file had a read error. In checking the event logs I saw a lot of "The IO operation at logical block address 9837 for Disk was retried.".

So I decided to run chkdsk, which comes back clean. So I run checkdsk with /r and it came back with both:
```
A disk read error occurredc0000185
The disk does not have enough space to replace bad clusters
detected in file 59036 of name \MyFiles\Myfile.ext
```
Which was the file I originally had trouble with, plus another file. But chkdsk ultimate concludes with:
```
Windows has scanned the file system and found no problems.
No further action is required.
```
No, correct me if I'm wrong, but wouldn't a (previously un-corrupted, and fortunately backed-up) corrupted file (or two) with bad cluster be considered a problem?
- Ramhound about 10 years
  
  It is but the file likely was moved to another sector.
- cybernard about 10 years
  
  In addition it says it does not have enough free space to replace bad sectors. How much free space do you have on the hard drive?
- and31415 about 10 years
  
  If you don't use the /r parameter, chkdsk won't scan the disk for bad clusters, ignoring free space as well.
- Michael Cook about 10 years
  
  There's about 10% free which is why I was copying files to a new drive in the first place. Without '/r' chkdsk wasn't reporting any problems, which is clearly wrong.
Michael Cook about 10 years

The drive is being replaced for sure, but I would think there would be a warning status or something. Having the tool say there are no problems while the drive is going corrupt completely devalues the tool.
LawrenceC about 10 years

You're expecting too much out of CHKDSK, it's job is to make sure there's a consistent and valid filesystem, not repair corrupted files. Error message could be better, but then it wouldn't be a Microsoft tool. ;)