iPhoto library vs Photos library?!

1) How do I have to deal with these 2 libraries since they are both very big and I would like to free some space on my SSD? Can I delete iPhoto Library.migratedphotolibrary if I do not use iPhoto anymore?

Yes you can, but it won't get you any space back. While both apps report a library of - say - 100 gigs, it's the same 100 gigs. They are both managing the same set of photo files.

2) In case I decide to keep a backup of it, will I be able to reuse iPhoto in the future by copying back that migratedphotolibrary in my mac Pictures folder?

You won't have to copy it back, you can open it from wherever you put it, as long as it's a directly connected HD formatted Mac OS Extended (Journaled).

3) I am wondering why I did not get any warning or message about the existence of 2 big libraries which are using almost 100GB each if one of the 2 could be deleted.

See 1. above.

In case I decided to uninstall iPhoto, would its migratedphotolibrary be deleted automatically?

No, you need to delete both.

What is the way to uninstall it, just drag it to the trash as per the other software?

That's it.

a - because the database structures are different and the support files are different for iPhoto and Photos - hence a small size difference in the libraries

b - yes - keep both especially since you state that you are not sure you like Photos - if you trash your iPhoto library then you can not go back

c - no - see b

d - yes - their libraries are totally separate except for starting with the same photos - changes made in one have no effect on the other one

LN

I'm sorry if there's a thread already going on this but I'm trying to understand the difference between the iPhoto library and the photos library. I just bought an external hard drive and I want to back up my pictures but I don't know which of these libraries I should back up or if I should back up both of them? Can you help here?

Back up both.

That said, the difference is simple:

iPhoto makes changes only to the iPhoto Library.

Photos makes changes only to the Photos Library.

At some point in the future (or now...) you might decide that you no longer use iPhoto, and then you can delete that Library. Photos will be unaffected by this.

Hello Terence,

I had the same question that Jet had. You're saying that Photos and iPhoto pull from the same photo folders? I did some digging around on my computer before I found this thread and saw that the same photos on either Application have a different file locations. I've included an example screen shot to show what I mean. They have the same file path with the exception of "iPhoto Library" vs "Photos Library".

Also, if you check the "Username" > Photos folder size, it's ~48GB, while each Photos and iPhotos library is ~24GB each. Which leads me to believe that they are separate.

Thanks, Joe

You're saying that Photos and iPhoto pull from the same photo folders?

No, I'm not.

Remember that things like folders and files are a metaphor for what's actually going on. They don't actually exist. On your HD there's a cluster of data that is your photo. Both apps point to that cluster of bytes. What you're seeing is how they designers represent that to you, that's all. So, they share the same original cluster of bytes, thereafter they are quite independent. So, if you delete the picture in iPhoto, the cluster of bytes remans, if you delete it in Photos, it remains, only if you delete it in both is it gone.

Okay thank you for the clarification. It just seemed strange to me that Finder would say the Photos folder size is equal to the sum of both Libraries. But I decided to try deleting the iPhoto Library (because I don't use that Application anymore anyway), and my total free space didn't change as you said it wouldn't.

The only files that get shared are those that were in the iPhoto library at the time of the initial migration. If those files were imported later into iPhoto and Photos separately they won't be shared.

To test if the image is being shared follow what user léonie sent to me on how to do just that:

If the masters in the migrated iPhoto library and the new Photos library are joined by a hard link, both files should have identical inode numbers in the file table, and that is indeed what I found, when I checked the indoor numbers for a few original files with "ls -li"

The indoor numbers in the migrated iPhotolibrary and the photos library are identical.

$ ls -li /Users/dreschle/Pictures/Photos\ Library\ Test2.photoslibrary/Masters/2012/07/19/20120719-153437/P1190028.JPG
31358709 -rw-r--r--@ 2 dreschle staff 2510146 Jul 19 2012 /Users/dreschle/Pictures/Photos Library Test2.photoslibrary/Masters/2012/07/19/20120719-153437/P1190028.JPG

$ ls -li /Users/dreschle/Pictures/iPhoto\ Library\ Test2.migratedphotolibrary/Masters/2012/07/19/20120719-153437/P1190028.JPG
31358709 -rw-r--r--@ 2 dreschle staff 2510146 Jul 19 2012 /Users/dreschle/Pictures/iPhoto Library Test2.migratedphotolibrary/Masters/2012/07/19/20120719-153437/P1190028.JPG
Hermione:~ dreschle$

Open each library's package and located the same file in both their Masters folder.

Launch Terminal, enter "ls -li " and drag one of the files into the Terminal window followed by the Return or Enter key.

That's ls space -li space

If both numbers as shown in red above are the same the two files are sharing the same data on the HD.

i want com back my photo lost 2days ago

If you have a question start a new thread and provide clear details of what you have, what is happening and what you want to know

See

Writing an effective Apple Support Communities question

LN