Surface Test USB drive then connecting to Mac (using exFAT)

[Octavehl]

I have USB drive formatted with exFAT by Mac (M1 MacBook Pro, Monterey, 12.1).
exFAT because I need to also use this USB drive on Win10 laptop. Formatted by Mac because exFAT formatted by Win10 caused many errors.

Question: Can I use any of the Surface Test on HD Sentinel Pro(ver 5.7) and have no issue connecting to my Mac afterwards? Even with Read + WRITE + read test, Reinitialize disk surface and Disk Repair? Will any of the test mean I need to format again with Mac and could that mean those bad clusters are available to be accessed again? i.e. back to square one.

My goal is to detect & reallocate bad clusters so those are no longer accessible by Mac or Windows.
I just want to minimize Bit rot impact so if there's any best practice on what test to do etc. that would be highly appreciated.

Many thanks in advance.

[hdsentinel]

I can confirm that yes, you can use any (all) tests of Hard Disk Sentinel on the USB disk drive, regardless of the partition(s) and regardless of where formatted originally (and the type of the partition).

Generally all tests in Hard Disk Sentinel work in a "low" sector level: so even if the USB drive would have no partitions (or partitions formatted for Linux / MAC which are not readable under Windows) Hard Disk Sentinel can still perform the tests to diagnose, reveal and stabilize possible problems.

You can use the Read+Write+Read test to refresh the stored data: as described in the description of the test, this reads the data, writes back and then reads again to verify/compare and confirm that the original data can be read back (so not altered/damaged). By default, it cycles all sectors (writes special patterns before writing back the original data) too, just to ensure that sectors could be re-written properly. This additional step can be disabled if required: if you select Disk menu -> Surface test and the drive+test type, then before starting the test, select the Configuration tab and disable the "Extensive read-write-read test with additional write operation" option at the bottom.

Yes, in addition you can use any other tests too, for example a simple Read test to reveal problems, Disk Repair test to fix/stabilize (and even the Quick Fix test in the latest 6.01 version too) and so.

Please note that the Reinitialize disk surface test clears all data - so while you can use it too, be careful: it would clear all sectors (including the files, unused sectors, partition table, file system descriptors etc.)
This function performs industry/government standard data destruction - so DO NOT use it if the drive contains important data.

Personally I'd use Disk menu -> Surface test -> Read test. This verifies the disk surface: reveal any possible problems, for example
- unreadable sectors (marked with red)
- damaged sectors requiring a retry (yellow)
- slowly performing sectors (darker green)
and would perform the refresh or other test only if required. If the resulting disk surface map is solid light green (so all sectors could be read with no errors/retries and with proper speed) then there may be no need to perform the refresh test.


> My goal is to detect & reallocate bad clusters so those are no longer accessible by Mac or Windows.

The Read test detects them - and if required the reallocation will be done by the Disk menu -> Surface test -> Disk Repair test (and the new Quick Fix test too) on drives with data.
The Refresh test does NOT do this, as it designed to refresh perfectly working but slower drives (eg. hard disks, SSDs, flash storage and so).
If the drive could be erased, then the Reinitialize disk surface is the best solution to force the drive to reallocate all problematic sectors (usually I always recommend this if the drive has many problems and low health originally).

But first I'd perform a Disk menu -> Surface test -> Read test to ensure that all sectors are readable - and would only perform additional tests based on the results only.

[Octavehl]

As usual thank you for taking your valuable time to respond with very thorough and easy to understand explanation. Have used forum a while back and really appreciate your effort to look after the user community and work ethic. I'm happy to wait for your response because you make the effort to make sure all is covered and due diligence for accuracy (if feels that way, and perception is also important!).

Thanks also for the best practice guidance as with abundance of information on your website & choices, I do have trouble of figuring out what options to use for certain objectives/scenarios. These are not available in FAQ etc. as far as I'm aware.

One point I'd like to confirm. When you say reinitialization clears everything, does that mean even previously known bad clusters are unknown afterwards and so bad clusters could be accessed again and cause issues?

Many many thanks

[hdsentinel]

Thank you very much for your answer and kind words, really appreciated

I try to explain things and the FAQ and other areas designed exactly to cover most areas.
Not sure (for example) if you may checked the Support -> Knowledge Base articles and/or the Support -> Q&A Knowledge Base section at www.hdsentinel.com in addition to the FAQ.
There you may find typical hard disk cases and common situations (eg. about bad sectors).


> When you say reinitialization clears everything, does that mean even previously known bad clusters are unknown afterwards and so bad clusters could be accessed again and cause issues?

Of course NOT.
Any previously detected and reported bad sectors (if you see "nn bad sectors" in the text description of the Overview page in Hard Disk Sentinel) already reallocated by the drive, replaced by spare sectors.
This means that all further reads/writes are re-directed to a spare area: so even the tests (including the Reinitialise Disk Surface test too) test the spare sector instead of the original bad sector.
This is the purpose exactly of the spare area: to prevent (re)use of any possible known bad sector, regardless of any testing, partitioning, formatting, etc.

This is good - as these bad sectors will never make any more problems - just we need to ensure that all possible such bad sectors detected, revealed and stabilized - and there should be no more (as each reallocations can result damaged/corrupted data and having high number of bad sectors risk even more). But very small amount of bad sectors (even sounds surprising) can be acceptable if the status is stable and the drive constantly monitored.

Please check about bad sectors:

https://www.hdsentinel.com/faq.php#health
I have bad sectors and my disk health is 90%. Do I need to worry or ask for replacement drive?

and in the Help:
https://www.hdsentinel.com/help/en/57_desc.html


and about testing in general, exactly to reveal any possible problems - or confirm that the drive is now stable (and ideally perfect):

https://www.hdsentinel.com/faq.php#tests
Hard disk health is low or recently changed or I just installed a new (used) hard disk. How can I perform a deep analysis?

[Octavehl]

Thank you for the important carination and all the pointers to relevant info for me check out.

Cheers and thanks again.

Have a nice weekend.