GPT HDD Cannot modify partitions/read data after enclosure change.

Windows ver. 10 20H2 19042.685

I have a Sabrent external enclosure I have been using for years as a storage device. It contains a WD Red 4TB drive. It was formatted in GPT because of the MBR's 2 TB limit. When I place the drive into a different branded external enclosure, it only shows a 2TB partition with the remaining 1.7TB as unallocated. I cannot change the drive in any form or fashion using Windows built-in disk manager as it's all grayed out. I've had this happen in the past and I know I can use diskpart to wipe the drive and start over, which requires me to backup my data, and then format GPT using the new enclosure then copy the data back over. Or I can use 3rd party disk management software but the outcome is the same. Windows is some how making this GPT partition GPT Protected and I don't format it that way. I don't get what causes GPT Protective to activate and I really don't need it.

So my question is why does this GPT Protective kick in?

Can I convert GPT Protective to GPT non protective without formatting?

Thanks!

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I went ahead and performed a clean on the disk using disk part which removed the GPT Protective header. But here is a new problem I am bumping into. When I format it with the brand Fideco HDD enclosure and then move it to the Sabrent HDD enclosure, the drive becomes GPT Protective. But then I move the drive back to Fideco the drive is only GPT. And when I format it using the Sabrent drive and then move the drive over to the Fideco drive, it is now GPT Protective. If I format the HDD in the Sabrent enclosure then move it over to my backup Sabrent enclosure which is the same model, it works fine. So physically moving a drive that is formatted in GPT becomes GPT Protective when moved to another branded enclosure. Is that right? Why would this happen? If the enclosure fails I need to be able to take the drive out and place it into another enclosure without losing data. But that doesn't seem to be the case if the drive just locks up into GPT Protective mode when it gets moved to another enclosure. Am I missing something?

Thank you @jumanji and @macbostmaster for this great detailed information. Sorry for my late response.

To my understanding these enclosures are compatible with Windows 10 as well as previous OS's. Here is the Amazon link to the Fideco product. Amazon.com

Here is the link to the Sabrent product. Amazon.com

I guess I'll have to be more careful about selecting my enclosures. I had no idea new enclosures that are designed to work with Windows 10 can change the sector size which flags the GPT Protection. That being said, is there a way to verify how the enclosure will change the sector size? I do not see it on their product page.

Macboatmaster said:

.........I think you will find that the mere placing of the drive in the different enclosure will result in the problem you had before .........

No need to think. It is so. The OP himself has confirmed it

JDubbedN said:

.........I went ahead and performed a clean on the disk using disk part which removed the GPT Protective header. But here is a new problem I am bumping into. When I format it with the brand Fideco HDD enclosure and then move it to the Sabrent HDD enclosure, the drive becomes GPT Protective. But then I move the drive back to Fideco the drive is only GPT. And when I format it using the Sabrent drive and then move the drive over to the Fideco drive, it is now GPT Protective. If I format the HDD in the Sabrent enclosure then move it over to my backup Sabrent enclosure which is the same model, it works fine. So physically moving a drive that is formatted in GPT becomes GPT Protective when moved to another branded enclosure. Is that right? Why would this happen? If the enclosure fails I need to be able to take the drive out and place it into another enclosure without losing data. But that doesn't seem to be the case if the drive just locks up into GPT Protective mode when it gets moved to another enclosure. Am I missing something?

As stated in my post #6, I repeat "It is the bridge electronics and the firmware in it that sets the physical sector size whether it is 512 or 4096."

Now if you diskpart clean the HDD (meaning that all sectors are written zeros and are zeros) and put it into either of the enclosures you cannot run fsutil fsinfo ntfsinfo C:

Only when you format it to NTFS in each enclosure and run fsutil fsinfo ntfsinfo C: in it, it will find what physical sector size is set by the enclosure electronics and the firmware in it. Not otherwise.

When the OP performs the exercise as stated in my post #6, I expect the one formatted in the Sabrent enclosure to show Bytes Per Sector 512 and Bytes Per Physical Sector 512 when fsutil fsinfo ntfsinfo C: command is given and the one formatted in the Fideco enclosure and the command run it to show Bytes Per Sector 512 and Bytes Per Physical Sector 4096.

I am just curious because this is the first time I have come to know of this possibility of changing enclosures creating a "GPT Protected" problem. Seeing is believing.. Only that will validate the postulates posted here.

You see the HDD formatted in the Sabrent enclosure will have a physical sector size of 512 Bytes. When placed in the Fideco Enclosure the drive will show as GPT protected since Fideco will not recognise 512 byte Physical sector size..It can recognise only drives with physical sector size 4096.

In a similar fashion the HDD formatted in Fideco will not be recognised in the Sabrent enclosure since it will recognise only drives formatted with 512 bytes physical sector size.

I wish the OP carries out the exercise to show that when formatted inside the Fideco the physical sector size is 4096 bytes and the same HDD when formatted in the Sabrent enclosure will have a 512 bytes per physical sector. And that makes the transplant GPT protected either way.

( I don't have a Sabrent and a Fideco enclosure to prove that point. Neither do you have . So you can stick to your theory and perception and I can to mine !)