How to avoid the Error -36 when copying a Photos Library to another volume

by: léonie

Last modified: May 11, 2020 2:31 AM

3 1623 Last modified May 11, 2020 2:31 AM

The error -36 can occur, when the volumes are having a different file system format.

The file system format for a volume, where we want to store a Photos Library should be APFS or MacOS Extended (Journaled) and not case-sensitive. Both drives should be formatted without the case-sensitive option. And your external drive must not be used by Time Machine. Try to enable the "Ignore Ownership on this volume" option, if you have not yet done so. That will prevent permission and file ownership errors. Prepare the destination volume as described here: Move your Photos library to save space on your Mac – Apple Support

An error -36 can also be caused by incompatible filenames - filenames that are too long or contain ctrl-characters. This can happen, if you imported image files from third-party applications, that write illegal characters into a filename.

If all fails to copy the library to your external drive, you have two options:

The easy way out would be to use cloning software like Carbon Copy Cloner or Super Duper to copy the library over. But this way the unreadable files will remain dormant in the copied library and may be causing problems later.

It would be better to copy all subfolders of the library individually. This way you will be able to identify the files, that are causing the copy error. To copy the subfolders individually try this:

Create a new folder on the external drive. Name it "Photos Library Copy", without any filename extension. Then open the library package on your system drive by ctrl-clicking it and using "Show Package contents". Now drag each subfolder individually to the new folder on your external drive.
- If a subfolder fails to copy and you get again the -36 error, check how far the copy succeeded. Look into the partially copied folder in the destination folder. which is the last item that could be copied? Then look into the source folder, which item should have been copied next and failed. Skip it and copy the remaining items by selecting them in the source folder and dragging them over. This is the advantage of copying the subfolders individually. We can check, where the copy failed and detect the culprits.
- Once you copied everything that can be copied, append the filename extension ".photoslibrary" to the name of the copy. The icon should change to the Photos Library icon. Now double click the copy to open it in Photos.

Can this copy be opened in Photos and does it work?

If there are other error messages, check the destination volume or source volume with Disk Utility, to ensure that the file system is not damaged and there are no hardware issues: If Photos can’t copy or create a library - Apple Support