Q: Migration - Aperture to Photos
-
Dec 15, 2015 1:57 PMby léonie,HelpfulThe library you need to keep is "• Photos Library.photoslibrary (3.51GB)".
The liberary "Aperture Library.migratedaplibrary (now only 3.09GB!)" is your Aperture library. You can open it again in Aperture, if you change the filename extension back to ".aplibrary".
Yo can delete the "Aperture Library.migratedaplibrary", but it is not necessary, because both libraries are sharing the original files and previews y hard links, see: Photos saves disk space by sharing images with your iPhoto or Aperture libraries - Apple Support
You will not free much storage by deleting the Aperture library. The storage will only be freed, if you delete the corresponding hard linked file in the Photos library as well. SO I'd wait a bit, to see, if the migration went well, and until you are sure, that you do not need your Aperture library any longer to look up up meta data that are not displayed in Photos or similar.
-
Dec 15, 2015 1:32 PMby coxorange,Léonie, thanks for your answer. This is confusing! Following the given link I read:
"When you migrate a photo library from iPhoto or Aperture, the Photos app creates a new library structure but doesn't duplicate your images. Instead, Photos saves disk space by creating links to the original and preview versions of your images."
I understand, that for Photos the new structure "Photos Library.photoslibrary" gets created, which doesn't contain the master photos and previews (these stay where they are: in the original Aperture library now called "Aperture Library.migratedaplibrary").
How is it possible that I can delete "Aperture Library.migratedaplibrary" – then the linked master photos and previews would be deleted and no longer be available for Photos!? Or does some kind of "magic" happen during deleting, which moves the master photos and previews into "Photos Library.photoslibrary"...?
My migration went well, I checked all photos, I'm ready for deleting the Aperture library, but I really need to be 100% sure about what is/will be happening.
Thanks again!
-
Dec 16, 2015 3:17 AMby léonie,I understand, that for Photos the new structure "Photos Library.photoslibrary" gets created, which doesn't contain the master photos and previews (these stay where they are: in the original Aperture library now called "Aperture Library.migratedaplibrary").
It looks confuing because of the way hard links are working. That is very different from referenced image files.
A hard linked file is an exact copy of a file. It looks like the original file, and has the same file size, and you cannot tell which of the two files - the original or the hard link is the original. But the two files are stored on the same blocks on the disk. They are sharing the inode in the file table. That is why the Photos library and the original Aperture library seem to be containing the same images and are having the same size on the disk. Hard links are not references. You can delete the original file and the hard link will keep working. But deleting the original will not free any storage, until you delete the hard lined file as well. Only then the blocks on the disk will be released.
To convince yourself that the two libraries are hard links, check the inodes of the master files in the Terminal:
See: Six Colors: The (hard) link between Photos and iPhoto
If two files are hard linked, the inode numbers will be identical, when you list the file with the ls -licommand in the Terminal:
For example, looking into the packages of an new migrated Photos library and the original iPhoto Library. Everything looks duplicated with the same size:
The Terminal is showing this, when I type "ls -li " into the Terminal and drag one of the master files behind this command:
Hermione:~ dreschle$ ls -li /Users/dreschle/Pictures/Photos\ Library\ 2.photoslibrary/Masters/2015/05/28/20150528-184932/IMG_0966.JPG
39167952 -rw-r--r--@ 3 dreschle staff 1283723 25 Mai 12:00 /Users/dreschle/Pictures/Photos Library 2.photoslibrary/Masters/2015/05/28/20150528-184932/IMG_0966.JPG
Hermione:~ dreschle$ ls -li /Users/dreschle/Pictures/iPhoto\ Library.migratedphotolibrary/Masters/2015/05/28/20150528-184932/IMG_0966.JPG
39167952 -rw-r--r--@ 3 dreschle staff 1283723 25 Mai 12:00 /Users/dreschle/Pictures/iPhoto Library.migratedphotolibrary/Masters/2015/05/28/20150528-184932/IMG_0966.JPG
In both libraries are the files listed with the identical inode number 39167952, meaning they are linking to the same physical file in the file table. For the Finder both files are separate, regular files and so it is reporting the size twice.
When I compared the used space on my hard drive right after migrating the test library with 40 photos, the used storage had not been increased much:
-
Dec 16, 2015 3:04 PMby léonie,My hard drive was getting full and I saw that my photos library and Aperture library were each taking up around 400gb of space. I moved the Photos library to an external drive and it freed up 200 gb. If both libraries are sharing the same links, how can this be?
Originally the previews and originals will be shared. But as you work with the libraries and edit the photos, the previews will be replaced by newer, edited versions. also, the preview sizes may differ in aperture and photos, and the thumbnails will be different. so some files will not besmeared. Over time, less and less files can be shared, so you will free storage by moving the aperture library.
