16TB external SSD not able to format to AFPS in Disk Utility

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Fslayton1 Author

Level 1

4 points

16TB external SSD not able to format to AFPS in Disk Utility

Fresh 16 TB SSD out of the box attached USB-C to USB-C directly into port.

"The disk you attached is not readable by this computer"

Clicked 'Initialize'

Clicked External 'Drive Name'

Chose 'APFS'

Scheme: 'GUID Partition Map'

"unmounting disk...

creating the partition map...

Unable to write to the last block of the device. :(-69760)

Operation failed..."

It keeps failing at the last sector when trying to convert. First Aid passes. I've tried Erase and switching to APFS but nothing works.

Anybody have any ideas?

MacBook Air 13″, macOS 14.3

Posted on Feb 2, 2024 4:42 PM

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Answer 1

Feb 3, 2024 6:50 AM in response to Fslayton1

The number of responders here that have that specific brand and capacity 16 TB SSD probably approaches zero, so how could anyone determine another course of action other than exchange the drive for a replacement and try to format it as APFS again.

Did you select the drive identity entry in the Disk Utility side bar?

Apple does not ship 16 TB SSD and may not have tested Disk Utility against a drive of that capacity, or the drive is flawed.

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Answer 2

MartinR

Level 6

18,686 points

Feb 3, 2024 8:10 AM in response to Fslayton1

It would help if you provide the exact make & model of the SSD.

The error message would seem to indicate a problem with the SSD.

But you could try an alternate path ... in Disk Utility, select the Device, then Partition and make sure you have a GUID partition. Then format it as MacOS Extended Journaled (GUID partition map). If that is successful, then either convert the SSD to APFS (using Disk Utility) or reformat it as APFS.

Even so, I would be suspicious of the SSD and consider returning it for credit or exchange.

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