Can't mount APFS portable SSD drive

Question

Can't mount APFS portable SSD drive

Hello,

I was transfering data (photos) to my external Seagate SSD 2TB drive formatted in APFS. Everything transfered properly, so I ejected (CMD+E) the drive and then unplugged it.

When I plugged it in after a few minutes, nothing showed on my screen. So I went to Disk Utility on my Macbook and I can see it there, but when I click the "mount" button nothing happens again. No error, just nothing.

After trying First Aid I get such info:

warning: spaceman chunk 2011 free count 1039505 > block count 32768

warning: spaceman chunk 2056 free count 1017194 > block count 32768

warning: spaceman chunk 2105 free count 1038009 > block count 32768

warning: spaceman chunk 2124 free count 1017366 > block count 32768

warning: (oid 0x6eac) cib: invalid o_cksum (0xffffffffffffffff)

error: failed to read spaceman cib 23 at address 0x6eac

and then error (-69845).

What's interesting is when I use EaseUS to try recover some data, I do get some photos recovered. Is there anything I can do to fix the drive apart from formatting it?

MacBook Pro 14″, macOS 15.6

Posted on Aug 20, 2025 1:31 AM

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Answer 1

Top-ranking reply

iamshivam

Level 2

182 points

Sep 12, 2025 2:08 AM in response to Darth Envious

Those “spaceman chunk free count” warnings basically mean the allocation tables are toast, which is why Disk Utility can see the drive but can’t mount it. First Aid won’t be able to repair that, and forcing mounts could risk further damage. At this point, your options are: finish recovering as much as you can with Mac Stellar data recovery software, or if the data is critical, send it to a pro recovery lab. If you don’t need the files, you can erase and reformat the drive to make it usable again.

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Answer 2

a brody

Level 10

85,308 points

Sep 11, 2025 7:35 PM in response to Darth Envious

Take it to a forensic data recovery center like Kroll or DriveSavers if you wish to see if anything else could be recovered. When that many bad blocks show up, the drive is mechanically beginning to fail, and only forensic recovery to make that drive useful one last time and strictly for recovery.

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Answer 3

Sep 12, 2025 2:09 AM in response to a brody

Hey! Thanks, I will do just that.

Could you speculate why this happened to me? I wouldn’t like to happen again. I was copying files to the drive, waited till the process was complete, ejected the drive with CMD+E and then ejected from the USB interface. When I plugged it in to check if everything works, it didn’t want to mount and I was stuck…

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