I am looking for a way to compare the contents of two large folders (multi-terabyte), one of which was copied and pasted to a different external hard drive, to confirm that all the subfolders and files were copied correctly because the copy process was done in stages over time. Any suggestions?
I need to confirm that the copy process was done completely and correctly because I will be deleting the first copy and these are important files. A second reason is because I am running out of space on the first drive.
The only way I know to do that would be to use the Terminal and the diff command. Not sure on your experience using the Terminal, but here's how to do it.
Launch Terminal. Then type this, put a space after it, but don't press Return yet.
Now, go to the first folder in a Finder window. Drag that folder to the Terminal window. That should put the path to that folder after the command.
Then do the same for the second folder. So, as an example, it may look something like this now:
diff -rq /Users/name/Documents/something /drive/somethingelse
Basically, it is "diff -rq " followed by two full paths to to folders that you think should be identical.
Then press Return. You may get it asking for permissions now to check these folders. Then you should get a report. If may take a while if these folders are huge.
The "r" tells it to look inside of subfolders. The "q" tells it to only report the things not found.
Thanks very much
Searching for "diff" on the App Store provides lots of options.