Mac mini M4 not recognizing external hard drives that work on Mac Pro

Question

Andre Bisson Author

Level 1

1 points

Mac mini M4 not recognizing external hard drives that work on Mac Pro

I am with a Mac Mini M4 since last year. I made a Time Machine backup in 2025. It was OS 25 then.

And now I find myself having OS 26.6.1 and I wanted to backup my mini before going to OS 27.

So I take out my Seagate 2000 GB onto which was the copy of the one done in 2025, my mini does not

recognized the disk anymore.

Bought a new cable and change the external container that I use to use from Voyager stand to Acasis and back.

Nothing, so I have a few external Hard disk that are 2 tb and none are recognized anymore.

I open my old Mac Pro 5,1 and the hard disk appears and all of them are opening on the mac pro.

So I reformat one of them that was almost empty and try it on the Mini and nothing. is showing up

I have tried all the method that I found on Internet, without much success.

I see it on Terminal, but cannot mount it, I am not very good on terminal by the way.

Install Menu NTFS for Mac that I took on the Seagate website, but it does not show my backup.

I have come to wish to return to OS 25 and forget all the updates even if they are wonderful but could not do it for now.

I am 78 now and I always enjoyed for the 40 years of usage on Mac, but right now I am tired and frustrated.

Thank you and I hope I gave enough informations on my situation. I have bought many Seagate Hard Disk through the years and none of them are showing up on the mini but they all show up on the Mac Pro 5,1

Mac mini, macOS 26.6

Posted on Nov 10, 2026 9:12 AM

Answer 1

kaz-k

Level 9

53,902 points

Nov 10, 2026 9:46 AM in response to Andre Bisson

Hi,

I just wonder if your external drive is self powered drive or bus powered one. If it's a bus powered, your Mac mini is not able to supply good enough power to the external drive since Apple Silicon Mac is inherent bus power.

Answer 2

Nov 10, 2026 9:55 AM in response to Andre Bisson

Andre Bisson wrote:

I am with a Mac Mini M4 since last year. I made a Time Machine backup in 2025. It was OS 25 then.

macOS 15 (Sequoia)? There were no versions of macOS between 15 (Sequoia) and 26 (Tahoe).

I open my old Mac Pro 5,1 and the hard disk appears and all of them are opening on the mac pro.

A Mid 2010 or Mid 2012 Mac – capable of upgrading to macOS 10.14 (Mojave) if a Metal-capable graphics card is installed. macOS 10.13 (High Sierra) is where Apple introduced APFS, so High Sierra or Mojave presumably would be capable of recognizing an APFS-formatted volume.

However, when APFS first appeared, I believe that Time Machine did not yet know how to back up files to an APFS volume. It would back up things from HFS+ and APFS volumes to HFS+-formatted Time Machine volumes. Later, Apple rewrote Time Machine, and current versions prefer to store backups on APFS-formatted volumes.

Install Menu NTFS for Mac that I took on the Seagate website, but it does not show my backup.

Time Machine does not support storing backups on directly-attached NTFS-formatted disks. So I'm not sure why you'd expect installing a third-party NTFS filesystem driver to make any difference when it comes to recognizing a drive that was correctly formatted for Time Machine and in use as a Time Machine backup.