HT204476: Photos saves disk space by sharing images with your iPhoto or Aperture libraries

Learn about Photos saves disk space by sharing images with your iPhoto or Aperture libraries
lynnefrombc

Q: I'm totally confused by this article...

Article HT204476 "Photos saves disk space by sharing images with your iPhoto or Aperture libraries".

 

It says Photo doesn't duplicate our photo images, instead it creates a structure which links to the images in the iPhoto library.  That sounds like Photo doesn't work independently.  But then it goes on to say any edit we do to a photo in iPhoto won't affect the image in Photo.  Also says it's unnecessary to delete the iPhoto library after the migration because the new structure takes so little extra space. 

 

If Photo works by creating links to the images already in iPhoto, I would have thought that if we deleted the old iPhoto library, those photos would all be deleted.  When I look at Finder/Pictures and see an iPhoto Library icon - isn't that where my photos actually reside?

 

I haven't done this yet, and I want to understand as much as I can before I do.  So far most of it seems pretty clear, but I can't get my head around this article :/

 

Thanks for any help,

Lynne

iMac (27-inch, Late 2013), OS X Yosemite (10.10.1)

Posted on Jul 12, 2015 3:27 PM

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Q: I'm totally confused by this article...

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  • Helpful answers

  • by Niel,

    Niel Niel Jul 12, 2015 3:32 PM in response to lynnefrombc
    Level 10 (311,939 points)
    Jul 12, 2015 3:32 PM in response to lynnefrombc

    Photos creates hard links, which are indistinguishable from the original files. They can be considered as residing in both libraries, and if one is deleted, the other won't be affected.

     

    (130124)

  • by lynnefrombc,

    lynnefrombc lynnefrombc Jul 12, 2015 4:05 PM in response to Niel
    Level 1 (14 points)
    Mac OS X
    Jul 12, 2015 4:05 PM in response to Niel

    Oh oh - I guess I'm not versed enough in the terminology - to me, links are something that simply join two or more other things together. 

  • by LarryHN,Helpful

    LarryHN LarryHN Jul 12, 2015 4:07 PM in response to lynnefrombc
    Level 10 (84,210 points)
    Photos for Mac
    Jul 12, 2015 4:07 PM in response to lynnefrombc

    You have a file (in this case it contains a photo) and multiple programs have a hard link to it so to each program it looks like it is local for  that program but in fact it is shared - so when you delete he iphoto library al you do is delete the hard links from iPhoto - as long as at least one hard link exists the file is not removed from disk - this allow multiple programs to use the same data with using additional space or other resources

     

    So trashing the iphoto library saves very little space

     

    Hopefully that helps a bit

     

    Photos saves disk space by sharing images with your iPhoto or Aperture libraries - Apple Support

     

    LN

  • by lynnefrombc,

    lynnefrombc lynnefrombc Jul 12, 2015 4:24 PM in response to LarryHN
    Level 1 (14 points)
    Mac OS X
    Jul 12, 2015 4:24 PM in response to LarryHN

    Oh, a light dawns (slightly, anyway lol).  I think I get it now.  That explains why changes don't flow through.

     

    So where is this central file containing my photo, that each program has a hard link to?

  • by Niel,Helpful

    Niel Niel Jul 12, 2015 4:29 PM in response to lynnefrombc
    Level 10 (311,939 points)
    Jul 12, 2015 4:29 PM in response to lynnefrombc

    There is no central file. A hard link to an item can be treated the same as the original item, except that deleting one instance of it won't affect the other.

     

    (130126)

  • by LarryHN,Solvedanswer

    LarryHN LarryHN Jul 12, 2015 4:29 PM in response to lynnefrombc
    Level 10 (84,210 points)
    Photos for Mac
    Jul 12, 2015 4:29 PM in response to lynnefrombc

    It is not a central file - each photo is in a file - and they can be anyplace (remember files are not really "in a Place" - they are bits on a disk and the directly is the index to finding the file (which may be scatted in different places) - frankly it is not necessary to understand the file system and exactly how it works to use the computer unless you write File System software for a living

     

    You are thinking of a file as physical thing like a book on a shelf - it is not - it is just bits and is only a file because the file system knows where those bits are

     

    LN

  • by lynnefrombc,

    lynnefrombc lynnefrombc Jul 12, 2015 4:50 PM in response to LarryHN
    Level 1 (14 points)
    Mac OS X
    Jul 12, 2015 4:50 PM in response to LarryHN

    Oh my gosh.  I will keep your reply and re-read it periodically - if for no other reason than to keep myself humbly grounded.   LOL I'm blushing - I think I need to apologize for asking a question for which the answer was clearly SO far over my head! 

     

    No, I didn't know files aren't really "in a place" - and after reading your reply I can assure you I will never again try to understand the file system.

     

    I did try googling "hard link" before you wrote it, but the explanations I saw were far beyond me. 

     

    Thank you so much for your amazingly clear explanation of this complex matter, in your previous post - you brought it down to a level I can understand and I definitely appreciate that.

     

    Thanks also, for your patience!

  • by lynnefrombc,

    lynnefrombc lynnefrombc Jul 12, 2015 4:54 PM in response to Niel
    Level 1 (14 points)
    Mac OS X
    Jul 12, 2015 4:54 PM in response to Niel

    Thank you - that's not something easily understandable to me.  Amazing stuff!

  • by LarryHN,

    LarryHN LarryHN Jul 12, 2015 6:12 PM in response to lynnefrombc
    Level 10 (84,210 points)
    Photos for Mac
    Jul 12, 2015 6:12 PM in response to lynnefrombc

    You are welcome

     

    LN

  • by Robocheme,

    Robocheme Robocheme Jul 18, 2015 5:21 AM in response to Niel
    Level 1 (0 points)
    Jul 18, 2015 5:21 AM in response to Niel

    I sort of understand the link concept.  However if all I'm after is to completely delete photos because they are duplicates or out of focus, etc,, how do I do that?

     

    If I use command + delete in Photos, does it completely remove the file and the links in Photos and iPhoto?

     

    Thanks,

     

    Cliff

  • by Niel,

    Niel Niel Jul 18, 2015 6:54 AM in response to Robocheme
    Level 10 (311,939 points)
    Jul 18, 2015 6:54 AM in response to Robocheme

    You open each library and delete it.

     

    (130391)

  • by Old Toad,

    Old Toad Old Toad Jul 18, 2015 9:49 AM in response to lynnefrombc
    Level 10 (140,913 points)
    Photos for Mac
    Jul 18, 2015 9:49 AM in response to lynnefrombc

    Read this article:  The (hard) link between Photos and iPhoto. It may help.

    OTsig.png