I'm attempting to copy an 84 Gigabyte photo library from an external Case-sensitive Journaled HFS+ disk to a newly formatted case-insensitive APFS SSD. The external disk is in an external drive bay connected via USB.

The operation takes a few hours, at which point I'm greeted with the error message

You can’t copy this file because its name is the same as other items on the destination volume, and that volume doesn’t distinguish between upper- and lowercase letters in filenames.

There is no duplicate file on the drive.

Is the file name being cached somehow because of the file size? Is it something in the package contents? The file integrity is fine - I can open it as a photos library from the bay. I thought I could open it as a referenced file and use the Photo's Consolidate option to simply get around the issue, but "Show referenced file" and "consolidate" are both greyed out in the file menu.

Can I use rsync or some other method to copy the file or are there actual case-sensitivity issues in there I need to address? It's my wife's entire photo collection, so I'm proceeding with extreme caution, and would greatly appreciate guidance.

  • 1 Can you try compressing, copy-paste and decompress, I hope you have that much space available? 2 this is a totally unverified idea, but when you do a "Show package contents" in right-click menu, you see half a dozen folders and some hidden files (cmd + shift + . ). Would copy-pasting them one by one and then putting them in a fresh empty .photoslibrary file created by Photos app work? 3 Leave the whole library aside and try to copy test files and folders if it is possible .
    – anki
    Jan 16, 2020 at 19:39
  • I'm not sure I want to risk a one by one package contents directory copy - that's a lot of time and the chance of a single mistake dorking the entire library is not null. I looked through the package contents and couldn't find any duplicate names (regardless of case). I'll give compressing and decompressing a try.
    – brianfit
    Jan 16, 2020 at 20:40
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    See but that's the mystery -- my FTP client shouldn't overwrite a file without a warning either. I checked the log and there were no failed transfers. I don't think there legitimately was a file with a duplicate name - only an errant system report that there was, and only when copying via a USB 2.0 connection. Maybe a temporary caching file?????
    – brianfit
    Jan 17, 2020 at 10:10
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    Copying 84GB via Finder is not recommended for a lot of reasons (including it being slow), so going with ditto, rsync, tar pipes or even just a simple cp is recommended
    – nohillside
    Jan 17, 2020 at 10:52

1 Answer 1


OP's solution:

in the end opened up my FTP client and transferred the file via my local ethernet. It worked!

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