Help with migrating Photos.app library

[alphaod]

So I have this drive with an old iPhoto library that is 563.2GB and this Photos library that is 891.7GB. The total disk capacity is only 971.98GB (1TB drive), so these numbers don't seem to add up. It shows only 27.55GB free space on the drive, so I bought a new drive to migrate the libraries.

That took some time to complete, but after the migration, the new drive has both the Photo library and the iPhoto library and my new 2TB drive shows 1.46TB used. I'm wondering if the old drive the iPhoto library is essentially referencing files in the Photos library, but when I copied them to new a drive, they became two separate folders?

Am I safe to delete the iPhoto library from the new drive since it's just redundant?

(Yes, I could techinically just test this out myself, but I'm running out of spare hard drives and there isn't enough free space on my Mac to hold the extra 563.2GB)

 

[Weaselboy]

I'm wondering if the old drive the iPhoto library is essentially referencing files in the Photos library, but when I copied them to new a drive, they became two separate folders?

Yes, that is exactly what is going on. It is called "hard links" and here is an article that explains it.

As long as you are sure all the images from the old iPhoto library got migrated into the new Photos library, then you can just delete the old one.

 

[ChrisA]

Wait until all of this gets backed up by Time Machine or whatever you use. THEN delete. There is no harm in having extra copies of data on a disk unless you are tight for space so you can afford to wait until you have a solid backup in place.

A hard link basically means that the same file shows in twice with two names, possibly in different folders. Deleting one of the two should not delete the data, the data is gone only after you delete the LAST file name associated with it. But are you SURE hard links are involved. We can't check this for you. The backup allows you to restore in case something goes wrong.

 

[alphaod]

Okay thanks. I dug up an old drive to mirror the new drive I got, but this is taking forever. Apparently there is a firmware bug that is causing really slow reads, but that's for another discussion.