Portable HD issue

[Jonathan Cross]

A copy of my image archive is held on a not very old 5TB portable HD.  The other day, when it was attached to my M1 Mac, it stopped working.  The Mac would not recognise it, despite the fact that it was obviously spinning.  The same was true with it attached to my 2019 MacBook Air.  Both Macs are running the latest Big Sur.  I have other portable HDs and they are fine on both machines using the same connection cables.  My portable HDs are all formatted as EXFAT, and I tried it on my old PC running Windows 10.  Bingo, it was fine.  I tried it back on the Macs but no luck.

I then reformatted it fully in EXFAT on the PC, i.e. not using quick format.  This took all night.  The PC recognises it, but again the Macs do not.   It does not appear in Finder, nor does its icon appear on the desktop.  As I write this, it is connected and was spinning, but now has stopped after about 10 minutes and its light has gone out.

Is there anything I can do to get the Macs to recognise it?   Even if I did get it going and put my archive back on it, is this problem a symptom that it would not be reliable, and I should replace it?

Thanks,

Jonathan

[mcbroomf]

Take a look in Disk Utility
If it shows up it will most likely be Unmounted
Try to Mount it (will possibly fail)
If it fails then I think the option is Erase (which will also reformat despite the Windows reformat)
It might then appear

If it's not seen in the Disk Utility then chuck it, but to be honest I'd be inclined to throw it out even if you can "fix" and mount it.  They are cheap and IMO you don't want iffy drives even as a redundant backup.

[Jonathan Cross]

Thanks Mike.  It does not show in Disc Utility so it is to be chucked.  I do have a spare 4TB portable HD, so will use that as 4TB is big enough.  Thank goodness for multiple copies of my archive!

Best wishes,

Jonathan

[Jonathan Cross]

I now have a 2nd external HD that won't work any more on my M1 Mac having done so previously.  Disc Utility recognises the second it but says it is unmounted.  I have tried first aid in Disc Utility, but that fails with 2 messages, Problem with Partition map and Disk with mount point needed -69854 so it Weill not mount.  With the first that I reformatted as EXFAT (as it was already), Fist Aid shows no partition issue and completes successfully.  The Mount tab is, however, greyed out so I cannot mount it.

I have searched on the web and this seems to be a known problem, particularly with Big Sur and M1.  Some to whom this has happened have had a long fruitless time with Apple Support.

I am not a happy bunny as I now have 2 portable hard drives that will not connect to my M1 Mac though both do to my old PC running Windows 10 and all the files show.  I am loth to connect anything else external till this is solved.  I also do not want to upgrade my MacBook Air to Monterey to see if that helps, as that machine does not recognise either HD in Finder or Disc Utility with Big Sur.

Are there any experts that can help?

Best wishes,

Jonathan

[Chris Kern]

I now have a 2nd external HD that won't work any more on my M1 Mac having done so previously.  Disc Utility recognises the second it but says it is unmounted.  I have tried first aid in Disc Utility, but that fails with 2 messages, Problem with Partition map and Disk with mount point needed -69854 so it Weill not mount.  With the first that I reformatted as EXFAT (as it was already), Fist Aid shows no partition issue and completes successfully.  The Mount tab is, however, greyed out so I cannot mount it.

It's difficult to diagnose a problem like this remotely, but assuming you don't need to move the drive that MacOS still recognizes between your MacOS and MS-Windows computers, you might try reformatting it as APFS or MacOS Extended, then see if it will mount properly.

For the drive that the MacOS Disk Utility fails to recognize, you might try performing a "low-level format" on it from your MS-Windows machine and then see if you can create one of the Apple file systems (or even an ExFAT system, if you have a particular reason for choosing that) on a MacOS machine.

[Jonathan Cross]

It's difficult to diagnose a problem like this remotely, but assuming you don't need to move the drive that MacOS still recognizes between your MacOS and MS-Windows computers, you might try reformatting it as APFS or MacOS Extended, then see if it will mount properly.

For the drive that the MacOS Disk Utility fails to recognize, you might try performing a "low-level format" on it from your MS-Windows machine and then see if you can create one of the Apple file systems (or even an ExFAT system, if you have a particular reason for choosing that) on a MacOS machine.

Many thanks. Chris.  Success.  The HD that Disc Utility recognised but would not mount, I reformatted using Erase as APFS as I do not need it to be interchangeable with Windows.  This is now fine and was mounted as part of the reformat.  The other that neither Finder nor Disc Utility recognised I did a full reformat overnight as EXFAT on my Windows machine.  Both Finder and Disc Utility now recognise it.  I have tried moving files to both HDs and that works, so I am back in action.

For the reformatting in Disc Utility, I used the excellent article on the Seagate website:

https://www.seagate.com/gb/en/support/kb/how-to-format-your-drive-macos-extended-journaled-on-macos-big-sur-and-later/

though obviously not as extended journal.

I hope that anyone else who has the same issue with an external HD on a Mac can find your advice.

Best wishes,

Jonathan