So, I just got unraid going. I'm still poking around getting to know how it all works. A few days ago I transferred something like 3tb from an hard drive in my gaming PC to my array. Everything seemed to go fine. But I want to know, right? Is there a method I can use to check that all the files on the array actually do match the originals I moved from, in file size, quality, whatever, before I delete them from the originating hard drive I am freeing up? Tried to find the answer with the jazz hands on the googler and the closest answer I found was that was called a "Diff check" but the links they had didn't go anywhere. Is there such a diff check utility that will work over the network like that? Originating hard drive is in a Windows 10 Pro machine.

Create checksum before the transfer then check them after.

Just to clarify a little, generate checksums on the original files, then generate on the copy. If they match you are good.

 

Doesn't particularly matter what program you use to generate or verify the checksums, as long as it's the same algorithm.

 

Keeping a copy of checksums for your files is good insurance anyway, as it allows you to monitor for corruption in general.

Can you recommend a good way to do that? I wound up using a program called freefilesync. Is something like that what you mean? I don't know how to generate checksums.

Note that unless there's a serious hardware issue most transfers should be 100% OK, since most pathways are protected, like Ethernet and disks (and RAM if you're using ECC), but it's still good to have checksums and they can come in handy for some situations if there are ever any doubts, I use Corz, you can easily generate checksums by folder and then check them by folder (or the complete share) on the destination if needed.