Value of iPhoto-xxx.migratedphotolibrary Files

I’m trying to save data from an old, inherited MacBook Pro (running Catalina and can not be upgraded any further) in preparation for wiping and donating/recycling it.

I’m having problems copying an old file titled iPhoto-xxx.migratedphotolibrary. My recollection is that such files are created when an iPhoto library is converted into a Photos library.

Assuming that the corresponding Photos library seems to be ok, is there any value to keeping its corresponding .migratedphotolibrary file?

Thank you.

UPDATE: May 5, 2022 6:21 PM
Corrected spelling of macOS 10.15 Catalina (H/T @aforkosh)

The only value to a .migratedphotolibrary file is if you are not sure that all of the photos it contains survived the migration. So long as the output Photos library has been checked to see it has the same photos (at least by count and sampling), the input library is dispensable.

Of course, that check should have been done at the time of migration. You are left to guess whether the old file was kept due to a known problem, in an abundance of caution, or just because the owner never got around to deleting it. (The two libraries share the original files, so the savings from deleting the old library would not have been great.)

I’m pretty sure that I’m the one who converted my parents’ iPhoto Libraries → Photos Libraries, so I guess I’m to blame for not deleting them earlier. :pleading_face:

As for the space saving due to hard links

I don’t know how hard links work when copying them across volumes, much less systems. Are the the connections really preserved when copied to a different Mac?

I’m pretty sure the space saving is lost if the libraries are copied to other volumes on either the same system or a different system unless you use a whole-volume copier (and even then, maybe).