chksk says it's fine HDS says it's bad

[Baatfix]

HI! What should I do, I don't use my 5Tb Hdd much, just backup for many things. Today I was backing up some files and noticed that the disk was bad according to HDS, so I ran chkdsk which found no bad sectors. What do you recomend to do?

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check disk F.jpg (578.64 KiB) Viewed 1734 times

[hdsentinel]

Thanks for your message and sorry for the possible troubles or confusion - but I can confirm that (at least if you're lucky) what you see is completely normal and expected.

Hard Disk Sentinel (as should) detected and reported the problems and issues with the disk drive,for example the bad sectors.

These bad sectors detected by the hard disk and thus reported in the text description are no longer used by the hard disk: they are already reallocated.
It means that a spare area is used for all reads and writes targeting those bad sectors, instead of the original sectors. This spare area is originally reserved, so the bad sectors (and the health decrease in general) does not affect the usable capacity.

Ideally, when all problems are stabilized then following surface tests (even the surface test in Hard Disk Sentinel) will not show problems.
This is good, as this way you can be sure that the original (bad) area does not contain important data and can't risk data loss.

Ideally in this situation we can say the drive is "perfect" (as all sectors seem working with no problems).
This is not really true because more sectors mean higher risk for possible data loss, data corruption or failure, but generally manufacturers allow more or less such bad sectors and may offer replacement only if the amount of such bad sectors reach a threshold (when hard disk health would be 0% in Hard Disk Sentinel).

Windows chkdsk tool (even if sounds surprising) does NOT fix/repair the disk drives in any ways.
That tool focuses on to fix/repair LOGICAL drives (partitions) only and even if seems weird, chkdsk can happily
- find errors on a perfect drive
- show perfect status for an almost failing drive
as it does not care the internal errors and lifecycle/statistics, degradation of the drive.

For example, please check this page:
https://www.hdsentinel.com/hard_disk_case_weak_sectors.php
which shows a very common issue with weak/pending sectors and explains how these reported and "fixed" (made things worse) by chkdsk and how these can be really fixed.

It is generally good idea to test, exactly to verify the situation - but it is important to use the proper methods. Other tools like chkdsk may be not sensitive enough, may not report all kind of problems (and can't help to fix them), as they may not monitor/show
- possible slower sectors
- possible retries
or other kind of problems, revealed/confirmed by Hard Disk Sentinel tests.

In contrast, by using the surface tests in Hard Disk Sentinel, you can verify if the currently used data area is error-free, there are no further errors reported (no weak, damaged sectors, no retries, no performance degradations, no further problems - during a controlled, managed test system, where all steps and the disk surface can be verified, examined). These are completely ignored by the other test methods like chkdsk.


In similar cases, this is why generally recommended to use better test methods (absolutely NOT chkdsk), as described in Support -> Frequently Asked Questions page -> Hard disk health is low or recently changed or I just installed a new (used) hard disk. How can I perform a deep analysis?
https://www.hdsentinel.com/faq.php#tests

First I recommend to use

Disk menu -> Surface test -> Read test

just to verify that the drive is now really stable and usable.

Ideally, after the repair, the test should show no
- yellow (damaged)
- red (bad, unreadable)
blocks at all. Some darker green blocks are possible and it is completely normal.

And after the tests shows that the status is stable, no degradations, it is possible to acknowledge the reported problems and remove them from the text description as then the software will only report future issues (if there will be).

This is described at http://www.hdsentinel.com/faq_repair_hard_disk_drive.php
generally and if you use Report menu -> Send test report to developer option, I can check the actual situation and advise with step-by-step details.


However, usually we can't expect too much from a hard disk with so low Health %: according the experiences, on drives with low Health % we can expect corrupted, damaged files, unreadable files/folders or "just" very slow disk operation. If you do not see similar then it is a very lucky situation.


This is generally not rare, explained numerous times on this forum already, for example at

https://www.hdsentinel.com/forum/viewtopic.php?p=18745
https://www.hdsentinel.com/forum/viewtopic.php?p=19687
https://www.hdsentinel.com/forum/viewtopic.php?f=32&t=12905&p=18544
https://www.hdsentinel.com/forum/viewtopic.php?f=32&t=12758&p=18267
https://www.hdsentinel.com/forum/viewtopic.php?f=8&t=12410&p=17695
https://www.hdsentinel.com/forum/viewtopic.php?f=18&t=12023&p=17124
https://www.hdsentinel.com/forum/viewtopic.php?f=32&t=11978&p=17051
etc...

[Baatfix]

Thanks for the explanation.