This is my first post here, thanks for helping out! I have two external hard drives, HD #1 is NTFS and HD #2 is Mac OS Extended (I think this is the same as HFS+). I am copying many files from #1 to #2 (docs, pics, etc). I want to verify that all items copied correctly.

On #1 (NTFS), folder A reports this size: 8,137,638,456 bytes (8.14 GB on disk) for 2,721 items On #2 (HFS+), folder A' reports this size: 8,137,677,392 bytes (8.14 GB on disk) for 2,721 items

How can I verify that everything copied correctly? Kaleidoscope isn't helpful for this, since it just shows that the folders differ, without specifying how.

Diff reports only this: that every subfolder in A' has .DS_STORE :

diff -r "/Volumes/WD Passport/A" "/Volumes/My Passport/A'"                                                  
Only in A': .DS_Store
Only in A'/SUBFOLDER: .DS_Store
Only in A'/SUBFOLDER: .DS_Store 

How can I verify that everything copied correctly? And is there something about NTFS and HFS+ file systems such that copying from one to the other results in different binary representations of files?

  • Do the sizes of the .DS_Store files add up to (approximately) the difference? – Sparhawk May 30 '17 at 2:13

You are comparing directory sizes on two different operating systems with two different file systems. There is no reason to expect them to be the same.

Your real question is how to verify that the data on drive 1 is identical to drive 2. The best tool I have found for accomplishing this is called hashdeep. For more than 12 years it has been my go-to tool to accomplish file integrity verification.

The Windows binaries and source code are available here.

For MacOS X, if you don't want to compile your own copy, you can obtain it from the Fink project. Sorry for not posting the link, but I am new here and don't have the requisite 10 reputation points to post more than two links. Fink can be found at www finkproject com

The way this tool works is that you create a list of file hashes from a source and then use the resultant hashes to verify that the copied files match. It's really straightforward, but you should be able to find some how-tos and videos via Google.

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