New drive, 100% health, 2 bad sectors after write+read test

[dbgt]

So I recently got a new 18TB WD external drive (that i was planning to shuck), since I connected it via USB 3.0 2 days ago, health and performance is reported as 100% before and after the test. I am using the latest version (beta) of Hd sentinel: 5.70.8. I will be using the drive in non-RAID, just as an individual drive.

I did a Write+Read surface test and this are the results:






The WRITE test finished without any problems, the Read test finished with 2 bad sectors

SMART values AFTER the write+read test (i didnt take a screenshot of the values before the test)


So my questions are:
1. Are the 2 bad sectors repaired? The Write+Read test description says it fixes any problems by reallocating bad sectors but the smart values dont show any reallocated sector.... So i dont know is the bad sectors are fixed, or not...

2. If the 2 bad sectors are not yet repaired, then how should i repair them? with the reinitialise disk surface or with the disk repair test? or is there another simpler and faster way of doing it? Because the drive is very big.. 18TB and I know exactly which sectors are bad, is it not possible to just directly repair this bad sectors instead of checking again the whole drive?

3. The drive is new, I got directly from WD store in a very nice black friday deal. The price was great and the lowest it has ever been (at least here in Europe) for a 18TB drive (269 euro) as far as I know. But still, it is a lot of money... should I just better return the drive as it has 2 bad sectors? I still have my return window open

4. Why is HD sentinel showing the drive with 100% health and not reporting the 2 bad sectors after the test in the overview panel??

[hdsentinel]

No, I can confirm that there are no bad sectors at all.
Exactly as you wrote, if there would be bad sectors, then the Health % and the Overview page (plus the S.M.A.R.T. page at the corresponding attribute) would surely reflect that.

As you can see in the log below the disk surface map "Verify error" reported. These do not mean that displayed sector is bad: the sector could be both written and read properly. The error reported because the written data and what Hard Disk Sentinel read back did not match.

While this sounds serious, I can confirm that in most cases this does not indicate problem with the hard disk itself especially if used with an USB enclosure/adapter/docking station, especially in a such situation when a really high capacity drive tested (so the test took really long time). In some rare cases the USB chip in the enclosure/dock (due to excessive data transfer) may overheat and can produce such/similar error.

Personally I'd click on the disk surface map and navigate to the displayed sector number 33021979078 just to manually inspect the result, verify what we can read back after some time and it matches with the pattern (eg. all zeroes if the default setting used for the Write+Read test).
Also I'd make a Write+Read test specifically on a small part, exactly to verify/confirm: select Disk menu -> Surface test -> Write+Read test but before starting the test, select the Configuration tab. Under the Limit testing to specific data blocks, you can specify eg. First block = 9350 Last block = 9400 (just to be sure) to specifically re-test that area and surely confirm if the sector is perfect and only the USB enclosure/dock caused the troubles.

Without seeing the status, I'm not sure but generally until the Health is 100%, there should be surely no bad sectors.

A tip: as I see, you use the latest beta 5.70.8 which has the Disk menu -> Device Specific Information function. I'd check that too, just to verify/confirm that the hard disk did not record any problems during the test.
And as always, if you use Report menu -> Send test report to developer option, I can check the actual complete status of the drive, just to be sure, to confirm that no issues with the disk drive.