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Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
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Using NTFS (logical) bad sector list to avoid (physical) one

July 8th, 2025, 13:50

Hi all,

I have a bad disk (a disk with bad sectors) that I want to keep for reasons.
Vast areas of the disk are ok, a few are not.

with the command chkdsk /R, Windows will find the physical bad sectors, and build a list of them, and tell NTFS to avoid them.

That is good.

1/ I have found that sometimes, if you launch chkdsk /R a second time, it will find more bad sectors. Sometimes less.
It is because chkdsk /R is agressive and try to retest the previously found bad sectors.
This is not what we want here.

2/ I can imagine that the physical defects are being bounced inside the disk when the stupid chkdsk /R tries to retest them.
This is not what we want here.

3/ On the contrary, what we want is to avoid all contact with an area that have been previously marked bad.
Also, when an area demonstrate slow read/write performance compared to its neighbor, we also would want to mark it bad.

4/ Slowly, with each pass, we would rule out all weak areas, and be left with the ok areas.

5/ Many people have tried this in the past. Some people tried to make dummy files, containing the bad sectors, that you would leave forever in a folder.
This is not what we want here. We want to make use of the NTFS bad sectors list. No dummy files.

6/ Some people tried to lock the bad sectors in unused partitions.
This is not what we want here. We want only one full partition.

7/ On any other forum, people would quickly respond : "Don't do that, buy a new disk"
This is not what we want here. This is hddguru elite forum, problems are solved, not avoided.

Example of such :
https://superuser.com/questions/694422/ ... a-recovery

So my question is, is there in existence, a piece of software that would mark NTFS sector as bad, not try to recover it, not try to reallocate in the free sector zone, just mark it as bad and never touch it again, and mark bad sectors with slow performance ?

Basically chkdsk /R without the stupid retest behavior.

Re: Using NTFS (logical) bad sector list to avoid (physical)

July 8th, 2025, 17:15

I suspect that this tool won't work with drives larger than 2TB:

https://files.hddguru.com/download/Software/Makebad/

The alternative is to use a tool such as HDDSuperTool to create a pseudo-uncorrectable sector via the ATA WRITE UNCORRECTABLE command.

Re: Using NTFS (logical) bad sector list to avoid (physical)

July 9th, 2025, 4:06

Thanks, I will investigate those two as you suggested and come back with a report.

Speaking of chkdsk still, has anyone any idea of what those parameters do ?
Code:
/scan                        Runs an online scan on the volume.
/forceofflinefix           (must be used with /scan). Bypass all online repair; all defects found are queued for offline repair (for example, chkdsk /spotfix).
/spotfix                      Use with NTFS only. Runs spot fixing on the volume.
/offlinescanandfix           Runs an offline scan and fix on the volume.


https://learn.microsoft.com/en-us/windo ... nds/chkdsk

Re: Using NTFS (logical) bad sector list to avoid (physical)

July 10th, 2025, 6:46

At file system level, the smallest addressable unit is the cluster, so clusters are marked bad, not sectors.

It would be better idea to at least try to get the drive to handle bad sectors (reallocate)

The reason you find no such tools is because it's a dumb idea.

I'm fine with solving problems, but you are creating them. This is not what we want here. You're being stupid, and you're asking us to fix stupid.
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