Apple Photos import: Insufficient Disk Space
I'm using an old version of Lightroom (version 5), I'm considering moving to Apple Photos (Mojave 10.14.5) because all I need are basic features. I have about 58,000 photos/videos (~1TB) catalog in Lightroom 5. These photos/videos are stored on an external USB drive.
I've moved the Photos Library to a folder on the external drive, which has about 530GB of free space.
When I tried to import, Photos complains "Insufficient Disk Space. Additional 760.47 GB of free space is needed to continue." In Photos, I've unchecked "Copy items to the Photos Library". Why does Photos
need this much space? I'm not trying to move photos. My photos are on the external drive. The "Photos Library.photoslibrary" file is also on the external drive. In Photos, I've unchecked "Copy items to the Photos Library" so I'm hoping that means that Photos won't make a copy of the existing photos. If that's true, then why does it need 760GB of space? Is Photos trying to make another copy of my entire1GB collection?
MacBook