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Large Photos Library on external drive

On new iMac, OS 12.1, my Photos Library is on an external hard drive. I recently Ejected it, and connected it to a different iMac to update the library. When I connected it back to the new iMac again, and tried to open Photos, an Updating Library... window opened with 0% completed and no movement for a long time, eventually it got to 5%.


The library is very large, over 400 GB, is that why it is taking so long to update? Will Photos eventually work from this external hard drive? (I will not use iCloud Drive for Photos)

I never had this problem on my old Mac OS 10.15.7.

Is this an issue with OS Monterey?

Is there a workaround?


BTW: my new Mac (Name: Amanda's 2021 iMac JS) does not appear on Devices list. How to add?





ARD 27"iMAC 2014 JS, iMac 27″

Posted on Jan 17, 2022 9:48 PM

Reply
Question marked as Top-ranking reply

Posted on Jan 17, 2022 11:51 PM

For your new mac to appear in devices, it will need to be logged into the same apple ID.


What is the format of the external drive? For compatibility with photos, it must be formatted APFS or MacOS extended (journaled) (preferred for spinning drives). If you have not formatted it after purchase it will most likely be ExFat - which is not compatible.

It Must not be (or have been) used for time machine. (A time machine drive can be used if re-formatted)

It must have the 'ignore ownership" checkbox ticked.

It must be directly connected (No ethernet or wifi)


See

https://support.apple.com/en-gb/HT201517


If it is not a compatible format, then permissions will be damaged each time you connect to a different mac, and need to be repaired on the other. For a large library such as yours, this will take a long time each time. This is why the ignore ownership is needed.


It is also possible (if the second mac you plugged into has a more recent version of MacOS) that that mac will have upgraded your library so that your current mac can't load it any more (It is not possible to share a library between two macs unless they have identical versions of MacOS - including minor versions).


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3 replies
Question marked as Top-ranking reply

Jan 17, 2022 11:51 PM in response to Live-n-Learn

For your new mac to appear in devices, it will need to be logged into the same apple ID.


What is the format of the external drive? For compatibility with photos, it must be formatted APFS or MacOS extended (journaled) (preferred for spinning drives). If you have not formatted it after purchase it will most likely be ExFat - which is not compatible.

It Must not be (or have been) used for time machine. (A time machine drive can be used if re-formatted)

It must have the 'ignore ownership" checkbox ticked.

It must be directly connected (No ethernet or wifi)


See

https://support.apple.com/en-gb/HT201517


If it is not a compatible format, then permissions will be damaged each time you connect to a different mac, and need to be repaired on the other. For a large library such as yours, this will take a long time each time. This is why the ignore ownership is needed.


It is also possible (if the second mac you plugged into has a more recent version of MacOS) that that mac will have upgraded your library so that your current mac can't load it any more (It is not possible to share a library between two macs unless they have identical versions of MacOS - including minor versions).


Jan 18, 2022 11:26 AM in response to TonyCollinet

Thank you for the clear & comprehensive answer which enabled me to learn more about my external hard drive.

Turns out it is formatted correctly Mac OS Extended (Journaled).


This morning when I opened the new 27" Mac, with that external drive attached, my Photos Library opened perfectly. I think the issue was that it took longer than I expected for it to open.


Great answer.


Large Photos Library on external drive

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