Can't mount external SSD on Mac Mini or Macbook

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Can't mount external SSD on Mac Mini or Macbook

I have 2 new 32T external SSD USB drives. When I connect them to my Mac Mini running Big Sur I can see the greyed out drive in disk utility but when I attempt to mount them I get the error com.apple.DiskManagement.disenter error -119930868

First Aid fails. Erasing and reformatting fails. Partitioning fails. Same thing happens with my Macbook pro running Ventura. I've tried mounting via disk utility and terminal with no luck. diskutil list shows:

/dev/disk9 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *35.1 TB disk9

1: Microsoft Reserved ⁨⁩ 16.8 MB disk9s1

2: Apple_HFS ⁨⁩ 35.1 TB disk9s2

(free space) 269.4 MB -

It shows Free space is only 269.4 MB.

Not sure what to try next.

Mac mini, macOS 11.2

Posted on Jan 2, 2024 11:11 AM

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Answer 1

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jimpoling Author

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5 points

Jan 3, 2024 7:54 AM in response to den.thed

Thanks for the help. It turns out that these drives will only work in a Mac when formated as ExFat. What's more, you have to format them in a Windows machine and set the allocation table to 256K. Then plug it into the Mac. If it doesn't show up in Finder right away, run First Aid in disk utility. Don't try formatting or changing anything drive related from the Mac otherwise you have to start over again and format them on the Windows machine. Seems a little weird to me, but I found a few articles and threads on line that said many of these SSDs react this way when it comes to Macs.

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