When you turn on computer backup, files on your PC or Mac are continuously backed up to the cloud. Any changes made in synced folders are automatically updated in your Dropbox account and on your hard drive. Access your files—whenever, wherever.
Did you move the actual Photos library, or did you move the individual photos? Neither is likely to do what you want, but the recovery will be different. Either way, you will need to put your library/pictures back into the normal file system, then look for another solution to your space shortage.
If you really moved the whole Photos library, you may have done irreparable damage to it and should restore it from your backup (ideally a Time Machine backup).
If you only moved the pictures from the Photos library to Dropbox, you'll have to move the back into the Photos library before you can access them from the Photos app.
Aug 23, 2018 8:49 PM
I see a lot of users of both PowerPhotos and iPhoto Library Manager who want to store their iPhoto/Photos library in Dropbox. This is totally understandable, as it would provide an easy way to keep your library synced between two Macs, and would be totally awesome… if it worked reliably. Unfortunately, the way the library is stored internally does not mesh well with how Dropbox’s syncing works, and can easily result in data corruption. Here’s how that can happen.
Photos uses a series of SQLite database files to store the data for the library. This includes thing like lists of all the photos in the library, all the metadata for those photos, how they’re organized into moments and albums, and so forth. Each SQLite database is essentially a single file (though a couple helper files are also used while the database is open) which contains however many hundreds or thousands of database records are required to store all the information for the library.
When you make a change in your library, such as creating a new album, Photos will modify the database with the new data necessary for whatever changes you made. SQLite makes this process very efficient, only needing to modify a small portion of the file to add/modify the necessary data, rather than having to write out an entirely new copy of the database file for each individual change.
Dropbox, on the other hand, performs all of its syncing on a per-file basis. So, when Photos make a small modification to one of its database files, Dropbox will copy the entire data file again. The sims 4 body hair mod. Here’s an easy way to demonstrate how this can cause data loss in your library, using two Macs, which we’ll call Mac A and Mac B. (everything here applies to iPhoto and Aperture libraries as well)
You will most likely see either Album A show up on both machines, or Album B show up on both machines, but not both. This is because, while both Macs have modified their own local copy of the library database, Dropbox does not have the smarts to merge the bits of those files that have changed together (nor should it). One of the databases will overwrite the other one, blowing away whatever changes were made there. Which one survives and which one doesn’t will depend entirely on the timing of Dropbox’s syncing.
If you’re less lucky, one or both of the libraries won’t be openable in Photos at all, which will display a message saying that it needs to repair the library database. Even if it successfully completes the repair, you will either only see one of your new albums in the resulting library, or perhaps neither of them.
Now, it is theoretically possible to make a setup like this work, if you make sure not to open both libraries at once, and always remember to close Photos on one machine before using it on the other, and always remember to wait for Dropbox to completely finish syncing your files before opening the library, and Dropbox never has a hiccup or delay in copying one of those database files, and so on. Oh, and if you decide to use this library as your system and/or iCloud photo library, meaning the system always has the library open in the background? Fugetaboutit.
This is actually more dangerous than an obvious immediate failure, because doing this can actually work OK, for a while at least. But you’re definitely playing with fire if you use this to sync your library on a long term basis.
Apple could try to add some sort of lock file that might prevent simultaneous opening of a library on two machines, but that would still leave plenty of room for syncing to screw things up, along with other various downsides. In my opinion, they should just disallow Photos from directly opening a library from Dropbox at all (filed with Apple as bug 20902778. They actually already disallow creating or opening a Photos library that’s stored on iCloud Drive, presumably for similar reasons (though the resulting error message isn’t exactly user friendly). I’m also planning on adding checks for this in the next updates to iPhoto Library Manager and PowerPhotos, to at least warn people about putting a library in Dropbox.