
Obvious step, but I mention it just in case. Step 1: sync both folders to be “available offline” What I ended up doing is baking up my own method, which is slightly overkill, but it does give me full confidence that the files really are intact. If the dates are different, Kaleidoscope shows that the files are different, even if their contents is otherwise the same. This didn’t work for the reason I mentioned before-Kaleidoscope compares all of the attributes of the files, including dates. What I expected to do is to just fire up a tool like Kaleidoscope, drag the two folders on to it, and be done with it.

Since there were tens of thousands of files in many folders, manual comparison was out of the question. I was in a situation where I had the same folder supposedly synced in two cloud providers, and wanted to make sure that it really checks out, i.e that there are the same files in the folders, and their content is intact. The “cloud providers” make this part fun, as many of them do tricks in the file system to not actually cache the content of the file locally until really needed, and some of them don’t preserve metadata like dates accurately. Since the files are crucial to the business, it’s really important to make sure that the move is completed well and the files are intact, that they all really got copied, and their contents hasn’t changed. My team sometimes needs to move a large number of files between storage systems, like different cloud providers. How do you confidently compare two folders in the year 2018? I expected there to be an easier answer to this question.

How to confidently compare the integrity of files in two large folders
