iPhoto Migrated Library (original)
Can I safely delete the iPhoto library (migrated) that won't open and save space without losing pictures?
MacBook
Question marked as
Top-ranking reply
Yes, if your Photos Library is working correctly and has all pictures and videos. Check it thoroughly, if there are any problems.
The Photos Library does not need the iPhotos Library it has been created from. But I would keep a backup copy on an external volume, just in case you notice any problems later.
You will not save much storage by removing the migrated library however (Photos saves disk space by sharing images with your iPhoto or Aperture libraries - Apple Support). The photos in your new Photos Library are sharing the storage with the photos in the original iPhoto Library. If you did not yet upgrade to Catalina and iPhoto is still running you can keep the iPhoto Library around and open it in iPhoto. Just change the filename extension back from ".migratedphotolibrary" to ".photolibrary". Then iPhoto can open it again, if you are running a system version, where iPhoto is still running.