FreeFileSync says "items have different content" intermittently

Posts: 3 · gx240 24 Jul 2023, 08:18

I just ran FreeFileSync using the "Compare file content" mode to confirm that a directory had been copied correctly.

When it finished, it listed 2 different files as "items have different content." So I manually checked each of the file's SHA1 hash values, and they match.

Then I ran FreeFileSync again with the exact same options, and this time everything matched.

Does anyone know what's going on? How can files be different in the first FreeFileSync run and then identical in the second run?

Posts: 4055 · xCSxXenon 24 Jul 2023, 13:41

If it isn't reproducible, there's no way to know definitively. What kind of files were they?

Posts: 3 · gx240 26 Jul 2023, 00:46

Both were 4GB .bin files.

Posts: 1 · jamesd 17 Sep 2023, 23:10

Can totally confirm this. It happened to me as well, and there's exactly zero chance that the files magically changed and then turned back to what they were. There is a serious bug.

Posts: 1038 · therube 19 Sep 2023, 16:49

I just ran FreeFileSync using the "Compare file content" mode to confirm that a directory had been copied correctly.

Do you mean that you additionally set, VerifyCopiedFiles?

"Compare file content"

Compare file content, itself, would compare the source file [content] against the target [content], to see if it needed to update one or the other.

Oh, oh, oh.
You're saying you ran a sync, which completed successfully, then immediately ran another Compare (File content method), & that (2nd) Compare reported that the files did not compare.

And then you ran a hash on the two files, & they did compare. Ah.