HDD bad sectors

[ZephyrArctic]

Hi! I recently had a power cut and my hard disk was suddenly shut because of that. After power resumed HD Sentinel showed this message:

There are 192 bad sectors on the disk surface. The contents of these sectors were moved to the spare area.
Based on the number of remapping operations, the bad sectors may form continuous areas.
There are 8 weak sectors found on the disk surface. They may be remapped any time in the later use of the disk.
More information: https://www.hdsentinel.com/hard_disk_ca ... ectors.php
It is recommended to examine the log of the disk regularly. All new problems found will be logged there.

It is recommended to backup immediately to prevent data loss.

The 8 weak sectors were present before (my HDD health was at 95% earlier, now it's 22% and status shows as "Error"). I have backed up my data and the process was smooth except in few places where the speed was very slow which I assume is due to the weak sectors. Only 1 file could not be transferred as it was probably corrupt. I checked the HDD with 3 other tools (Crystaldisk/HDDscan/WD Diagnostics tool) but it showed no problem in any of those and passed the SMART tests. What steps should I take now to repair my drive if it is still possible?

[hdsentinel]

Hi!

This is a very common situation, happens very-very frequently. Because of this, described numerous times on this forum already, for example at

https://www.hdsentinel.com/forum/viewto ... 05&p=18544
https://www.hdsentinel.com/forum/viewto ... 58&p=18267
https://www.hdsentinel.com/forum/viewto ... 10&p=17695
https://www.hdsentinel.com/forum/viewto ... 23&p=17124
https://www.hdsentinel.com/forum/viewto ... 78&p=17051
etc...

So I'd suggest to please search on the forum before posting the same again. Thanks


Generally the page https://www.hdsentinel.com/faq_repair_h ... _drive.php describes the situation, shows the recommended steps to
- perform tests to reveal and stabilize any kind of problems (which may be even hidden)
- and if the status is stable, there are no new problems then clear the error counters to restore the health and be notified about possible new problems only (if there will be).

In general, you do not need to worry about those bad sectors as these are already fixed by the hard disk: now the disk uses the spare area instead of these bad sectors, all read and write operations are using the spare area. This is called "reallocatation".

This is why the tests (even disk tests in Hard Disk Sentinel) shows no problems and manufacturers allow some of such bad sectors.

This is why other tools may completely ignore these bad sectors and not report them - which is a wrong approach: the reallocation process should not be completely ignored. If the drive status would be stable (no further sectors will turn to bad) then the drive can be used because the problematic area is no longer accessed, but having high number of such bad (reallocated) sectors is always risky as they may lead to further problems (corrupted/damaged/unreadable files/folders, partial or complete data loss) in the future.

The sections of the Frequently Asked Questions page may help:
http://www.hdsentinel.com/faq.php#health
http://www.hdsentinel.com/faq.php#tests

These describe the recommended steps to analyse the hard disks, reveal and fix any possible issues because the most important is to verify if the drive is really stable (there are no more, currently hidden problems).

It is generally good idea to test, exactly to verify the situation - but it is important to use the proper methods. Other tools like the mentioned ones, manufacturer-specific tools, chkdsk etc.. 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.

So 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.

Personally I'd try to use

Disk menu -> Surface test -> Read test

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

And in your case (as you mentioned that your hard disk has weak sectors) you'd need to use Disk menu -> Surface test -> Disk Repair test, which designed exactly to repair such weak sectors (it is described on the link you may see in the text description).

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_ha ... _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.

[ZephyrArctic]

Thanks for the detailed reply! I posted the thread as I was unsure on how to proceed.

I did a read test as per your suggestion and this was the result:

[ZephyrArctic]

This is the disk repair test results:

[hdsentinel]

Thanks for the images.

Yes, both are completely normal and expected in this situation.

As you can see, the READ test showed the actual location of the problems (the weak sectors). These required attention and fixing (as they were still used by the hard disk) - and the Disk Repair test successfully repaired this kind of problem.

By these tests you confirmed that the hard disk surface is stable, all sectors can be read/written and there are no problems (as the weak sectors also fixed, repaired). Now you can acknowledge the bad sectors previously found and reported by the hard disk drive.
By clearing the bad sector count, Hard Disk Sentinel will not report these any more, just shows possible new issues (if there will be) and this will result in increased health % too.

This method (perform testing to stabilize the surface and fix hard disk problems and then clear the error counters) is described at

https://www.hdsentinel.com/faq_repair_h ... _drive.php

and if you use Report menu -> Send test report to developer option, I can check the actual status of the hard disk (the bad sector count, the number of reallocation events and possible other issues which may require attention) and advise about how to restore the health with step-by-step details.