Ext hdd as Apple Photos library won't mount on new Mac mini M2 Pro

[Letterman]

Hello, Hopefully this is the right forum to get help for this issue. I have a 2018 MBP and I had a 6TB Seagate external HDD formatted and setup as the main (system) library for Apple Photos. I have over 4TB of photos and videos on it so iCloud storage was not an option for me. This setup worked well for two years or so. I needed to replace the MBP though and purchased the base 16/512 Mini M2 Pro yesterday. I used Apple's migration tools to setup the new mini, though the external Photos Library was not connected to the MBP at the time. When the new mini was all set, I connected the external drive via one of the mini's usb-a ports.

The drive did not show up in Finder. I launched Disk Utility and the drive was detected (the brand name and size), but the actual Photos Library was not (I had named it "ApplePhotosEXT" but it was greyed out). I ran first aid; the top level "Seagate" drive tested ok, but the ApplePhotosEXT was not able to be fixed by first aid. It also could not be mounted by Disk Utility. I then restarted the mini, but same result. Shut the mini down, disconnected the drive and connected it again to my MacBook Pro (the computer it was initially set up on). The drive then displayed the same behaviour; detected in Disk Utility but could not mount or be fixed by first aid.

I called Apple support and after discussing the steps I took, the recommendation was to erase the drive. The tech did say though that it should have worked on the Mini as well, so possibly something happened to the drive. I can't think of anything I did wrong though. Before I erase, does anyone have any insight into what may have happened? This isn't a backup or loss of images issue, as I have several backup disks and online solutions already. I just would like to know why this did not work, when it seems it should have. If there's any more troubleshooting advice I'd appreciate it. I'm also reluctant now to use this method again; I don't want the same result whenever I'm ready to sell the mini. Also looking at Mylio as an alternative all-in-one organizer with local storage, but Apple photos of course is not a subscription application.

Thanks in advance for any assistance

 

[chabig]

I don't know that anyone could tell you precisely what happened or what went wrong. But it does reinforce the benefit of backups. It's nice to read a post like this where a drive failure didn't lead to data loss.

 

[Letterman]

I don't know that anyone could tell you precisely what happened or what went wrong. But it does reinforce the benefit of backups. It's nice to read a post like this where a drive failure didn't lead to data loss.

Yes, thankfully with two other backup methods I didn't lose anything. Apple Photos is very convenient for searches and showing photos and videos to family, along with being able to combine images from two or three devices into one library. I'm hoping the drive is ok; I'll probably do the erase and reformat later tonight, and then let the new Library build overnight.

 

[Rich B22]

Hello, Hopefully this is the right forum to get help for this issue. I have a 2018 MBP and I had a 6TB Seagate external HDD formatted and setup as the main (system) library for Apple Photos. I have over 4TB of photos and videos on it so iCloud storage was not an option for me. This setup worked well for two years or so. I needed to replace the MBP though and purchased the base 16/512 Mini M2 Pro yesterday. I used Apple's migration tools to setup the new mini, though the external Photos Library was not connected to the MBP at the time. When the new mini was all set, I connected the external drive via one of the mini's usb-a ports.

The drive did not show up in Finder. I launched Disk Utility and the drive was detected (the brand name and size), but the actual Photos Library was not (I had named it "ApplePhotosEXT" but it was greyed out). I ran first aid; the top level "Seagate" drive tested ok, but the ApplePhotosEXT was not able to be fixed by first aid. It also could not be mounted by Disk Utility. I then restarted the mini, but same result. Shut the mini down, disconnected the drive and connected it again to my MacBook Pro (the computer it was initially set up on). The drive then displayed the same behaviour; detected in Disk Utility but could not mount or be fixed by first aid.

I called Apple support and after discussing the steps I took, the recommendation was to erase the drive. The tech did say though that it should have worked on the Mini as well, so possibly something happened to the drive. I can't think of anything I did wrong though. Before I erase, does anyone have any insight into what may have happened? This isn't a backup or loss of images issue, as I have several backup disks and online solutions already. I just would like to know why this did not work, when it seems it should have. If there's any more troubleshooting advice I'd appreciate it. I'm also reluctant now to use this method again; I don't want the same result whenever I'm ready to sell the mini. Also looking at Mylio as an alternative all-in-one organizer with local storage, but Apple photos of course is not a subscription application.

Thanks in advance for any assistance

If the drive is showing,but not the Library, I would just erase and restore from backup. I have no idea why this would have happened, however, I've had similar things happen when a drive had been disconnected for awhile, but that was when we were working with Firewire connections.
Good Luck

 

[Fishrrman]

"I called Apple support and after discussing the steps I took, the recommendation was to erase the drive"

Um.... please bear with me, I'm an old guy and not that smart (the avatar was carefully chosen).

But... you ERASED the drive with 4tb of photos on it?
Do you have a backup of this drive?

OK, the following applies if you DO have a backup:
a. connect the drive (with the photo library on it)
b. let it mount on the desktop. DO NOT "open" it.
c. click ONE TIME on the drive icon to select it.
d. now, bring up the "get info" box (type command-i)
e. at the bottom of get info, click the lock and enter your password (the one you're using with the new Mini)
f. put a checkmark into "ignore ownership on this volume" (sharing and permissions)
g. close "get info".

NOW open the drive and look around.
Is the photo library now accessible to you?

WHY we did all this:
Even if you used the same username and password on the new Mini as you did on the old MBP, the new Mini will still regard stuff from the MBP as "alien" (not of "the same account").
Thus -- permissions problems.
By taking the steps we did above, we have "overcome" such problems, and anything you copy from the external drive to the internal will "fall under the ownership" of your new account.

 

[Letterman]

"I called Apple support and after discussing the steps I took, the recommendation was to erase the drive"

Um.... please bear with me, I'm an old guy and not that smart (the avatar was carefully chosen).

But... you ERASED the drive with 4tb of photos on it?
Do you have a backup of this drive?

OK, the following applies if you DO have a backup:
a. connect the drive (with the photo library on it)
b. let it mount on the desktop. DO NOT "open" it.
c. click ONE TIME on the drive icon to select it.
d. now, bring up the "get info" box (type command-i)
e. at the bottom of get info, click the lock and enter your password (the one you're using with the new Mini)
f. put a checkmark into "ignore ownership on this volume" (sharing and permissions)
g. close "get info".

NOW open the drive and look around.
Is the photo library now accessible to you?

WHY we did all this:
Even if you used the same username and password on the new Mini as you did on the old MBP, the new Mini will still regard stuff from the MBP as "alien" (not of "the same account").
Thus -- permissions problems.
By taking the steps we did above, we have "overcome" such problems, and anything you copy from the external drive to the internal will "fall under the ownership" of your new account.

Thank you for all this, I wish I had tried it yesterday. I did erase the disk and am now rebuilding the library. It's strange the Apple tech I spoke to didn't mention anything about permissions, even when I explained carefully what I had done. For what it's worth the disk couldn't be mounted by either the new Mini or the original MacBook; it was not showing in Finder, so honestly, I just don't know what happened. Thankfully I had everything backed up elsewhere so it's really not too much trouble to rebuild it again. I gave me a chance to purge some older files that don't need to be in the Photos Library. Thanks again for the detailed reply