Moving photos to a new Mac from an old one - issues with permissions and iCloud OK here's the story. My wife's old Mac -- a late 2010 MacBook Air currently running Yosemite. We get a new Macbook Air (high end model) running Mojave. 

I use the Migration Assistant to transfer the data, it takes a while but it appears all is well, until we get to the photo library. 

"Could not repair permissions" it says. 

OK then. We have some photos on there but not all; it's stuff that was in iCloud storage. I think well, why not put all the photos from the old Mac into icloud and download it to the new one. 

So I try this - we upgrade to 50GB but it says it isn't enough (even though when we upgraded it said it should hold the whole library). 

All righty then, I think, I will see if I can't repair permissions on the old Mac and try again. 

But here is where I am confused. Apple's support says that if I delete anything from iCloud it is "Not available on any device" even if I store the originals on the old Mac -- thank God I did a Time Machine backup. Does this mean that when I upload photos to iCLoud I give Apple complete control, and that deleting them removes them from every device? How do I keep the originals then? What happens when I connect the old Mac to the Internet, do all my photos get erased? 

Secondly, I want to just transfer the photo library once I fix the permissions on the old machine and I am unsure how to do that without doing the whole migration process again. If I have to do that fine, but I'd like to know if I can do photos only and save some time. 

Thanks for your help, I hope this isn't too similar to what other people have asked, and if you answer pretend I am the dumbest person you ever met. :-)
I suggest that you use the export function of photos. 


from the photos app

.. be sure you click on the photos tab

.. command+a to highlight all photos 

.. click on file  

.. click on export 

.. export ...  [ you can pick either of the first two.  I don't know what you might want. If you have made photo edits in photos, you want the first one. ]





if you did't export the photos to an external drive, copy the photos to an external drive.
use the import function on the other machine. 


My view, in short, is that placing you photos in iCloud is a method for loosing them. I recommend you get your photos out of the Apple ecosystem and store them as one photo per file on multiple external storage devices. For long term storage, don't rely on usb memory sticks nor external ssd drives.  LoC does not have data on the reliability of usb memory sticks.  Apple seems to be saying do not store photos on external ssd drives.  One device should be off site.  Using a cloud service is fine.  Remember a lot of cloud services are sync services.  That is should the file be deleted on the local device, the photo will be deleted in the cloud.  For this reason,  I never install the cloud service software on my computer.  I use only file upload.  For those who complain, my assessment is that the apple Eco-system doesn't match Library of Congress's requirements for digital archiving.

informative video:
http://www.digitalpreservation.gov/multimedia/videos/personalarchiving-photos.html

printed version
http://www.digitalpreservation.gov/personalarchiving/photos.html

General information on digital preservation:
http://www.digitalpreservation.gov/personalarchiving/