Moving Photo Library - in use error

Question

Moving Photo Library - in use error

I am trying to move my Photos library from my main Mac HD to an external Samsung T7 SSD. I first performed a backup with a drag and drop to another drive. All good

But I noticed that, even with the Photos app closed, the last modified date of my Photos library file will update sometimes. For example, I have not opened the application today, but it says last modified today.

I followed all advice on here and erased my external drive, formatted it appropriately, no TM on it. I did a move instead of copy on the Photos library to the external. It required my fingerprint, and started. Strangely, on the disk the size was 734GB but the move was 1.3 TB. Anyways, it started moving, but after making it 90% of the way, it said operation can’t be completed because file is in use. I had not been using the computer, and every program was closed. Also, I had WiFi off and no internet connection.

When this happened, Finder ended up freezing. I left it overnight to see if maybe it just needed time, but still not responsive the next day, so I had to force quit. This ended up somehow bricking the SSD. I can’t get it to show up in Disk Utility or anything.

Anyone have thoughts on this? Should I go into the library and turn off iCloud Photos? Maybe it is doing some syncing in the background that I need to disable for the move?

I guess I could do a copy instead of move, and then just delete the original?

MacBook Pro 13″

Posted on Sep 6, 2025 6:31 AM

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Answer 1

Sep 6, 2025 9:23 AM in response to Yer_Man

Formatted to APFS Volume with GUID Partition Map.

Complicating the matter is that my Mac HD is nearly full. 3GB left out of 1TB, hence this move.

Any thoughts on why my Photos Library shows as 1.35TB, when my Mac HD is only 1TB?

I did a copy before, and it opened fine. But when I tried to mark it as the System Library, it failed. I assumed it failed because the main HD is almost full. Hence wanting to do the move.

New plan:

1) format drive freshly to GUID partition map and APFS

2) copy library to external

3) open library on external, scroll through and make sure it looks like all photos are there

4) close everything

5) delete library file from Mac HD (this step irrationally scares me)

6) open library on external, set as System Library, enable iCloud Photos, and allow sync to complete

Thanks for all your help!!

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Answer 2

Sep 6, 2025 7:53 AM in response to xtheguitarmanx

xtheguitarmanx wrote: …But I noticed that, even with the Photos app closed, the last modified date of my Photos library file will update sometimes. For example, I have not opened the application today, but it says last modified today.

The Photos Library is dynamic-- it's constantly being scanned by Photos, and the database is being updated. That's why it's dangerous to operate a Photos Library for a non-Mac formatted drive-- they don't handle this well.

I followed all advice on here and erased my external drive, formatted it appropriately, no TM on it. I did a move instead of copy on the Photos library to the external.

As Yer_Man said, I would never, ever erase data before verifying that it had copied completely and accurately.

It required my fingerprint, and started. Strangely, on the disk the size was 734GB but the move was 1.3 TB.

That seems odd, and it makes me wonder if you were doing what you thought you were doing. I am so glad you made a backup first!!

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Answer 3

Yer_Man

Level 10

165,918 points

Sep 6, 2025 7:23 AM in response to xtheguitarmanx

formatted it appropriately,

To what?

I guess I could do a copy instead of move, and then just delete the original?

That is inherently less risky with such a large amount of data.

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Answer 4

Sep 6, 2025 9:44 AM in response to xtheguitarmanx

xtheguitarmanx wrote: …5) delete library file from Mac HD (this step irrationally scares me)

Not irrational. I do two backups on two different external drives.

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Answer 5

Sep 6, 2025 10:34 AM in response to Richard.Taylor

Given that I already did a copy/paste backup, does my new plan miss anything, or does it seem correct?

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Answer 6

Yer_Man

Level 10

165,918 points

Sep 6, 2025 10:42 AM in response to xtheguitarmanx

Your plan is good but you don't have to wait till step 6 to designate the moved version as the System Library. You can do that once you're happy the copy has gone well. at step 3.

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