FreeFileSync Forum

... have figured out ways to get the hashes, but not with an API, and it requires some not-so plug-and-play stuff. They have notated using scripts, programs, and enabling things in the account settings.
MD5 checksum is a field in the JSON metadata for a file though, so maybe it's easier than expected?

I installed 13.7, and when I try to run, I get the attached message mentioning installation files are corrupted and invalid checksum. I reinstalled 13.6 and everything runs as expected. Any suggestions?

Error message reads
"Consistency check failed for "C:\Program Files\FreeFileSync\Resources\Registered.dat
Invalid checksum"

I have been running the donation edition for ages then this came up today.

I don't want uninstall/reinstall in case I lose my list of file matches.

Any suggestions??

Thanks ...

Theoretically, files can have an identical checksum and still differ in content.
That is however very, very unlikely, and, as explained in said threads, not the reason why FFS does not use hashes.

... Drive sync: by time and size and file content (byte-by-byte comparison)

However, I noticed that gdrive api v3 file metadata object exposes `md5Checksum` field.
Would be nice to add this as sync option. Previously for something like that to happen, you had to download file from a cloud (and there ...

... tried again - this time it appeared to work but when I looked at the .log it had apparently failed again because the sync files didn't pass their checksum (yet the backup had worked fine the night before).

I have attached my .ffd as well as the error.log file - could someone please tell me what ...

xCSxXenon,

Is there a way to tell free file sync to do a checksum after each file is transferred?

... check if they are the same. The -n flag tells rsync to do a dry run and not change anything. The -c flag tells rsync to compare the files using a checksum instead of just comparing the file sizes and modification times.

Here is an example of how to use it:

rsync -vnc /path/to/source/ /path/to ...

... 2023-06-13 14_23_59.331.log

Or even better

SyncSettings 2023-06-13 14.23.59_331.log

or [the best in my opinion]

SyncSettings 2023-06-13 14.23.59 331.log

or eventually

SyncSettings 2023-06-13 14_23_59 331.log


And by the way: what is that last 3-digit number? A checksum of some sort?

... of the changed file.

Only if some service would be running on the remote machine that can provide FFS the momentary hash of the remote file, a checksum based approach could/would potentially be attractive.
But as this is normally not the case, and depends on the remote file server, FFS can not ...

... pasting the same file to a different location in the drive on both sides is still detected by the software upon comparing them again). Or is the checksum of the file tracked by the file every time a comparison is run?

I've tried to read the documentation and search the forums before posting this ...

Delete that "sync.ffs_db" file and try again



This has been fixed for the next release:

FreeFileSync 11.28
------------------
Recover from corrupted database file

That was a regression compared to older releases. FreeFileSync will automatically overwrite a corrupted DB file, if the error is ...

I'll just point out the "very often" bit, which you would think you should not be running into, very often:

I get then very often (not always!!) this error message: cannot be read, the file content is corrupt (invalid checksum)

Delete that "sync.ffs_db" file and try again

Hello FORUM!
I have (for a long time already) a problem
with "FreeFileSync" for Windows 10.
For more see attachment: .jpg file.
Greetings from Germany
Sigmund

... such command will "hit" all files in scope, not just the ones just copied over or updated.

You could also have FFS invoke some self-created script-file via the FFS On Completion command line.
That script-file should then determine which file to determine the md5 checksum of, and consequently do so.

Freefilesync is a very great file sync tool, I use it every day.
And I use checksum file created by md5 command to check file integrity.
when I use freefilesync sync some new file to cold storage disk，then I need to
use md5 command create checksum.
step1. use ffs sync changed file
step2. find ...

... FreeFileSync.

Consistency check failed for "D:\Utilities\PortableApps\FreeFileSyncPortable\App\FreeFileSync\Resources\Registered.dat".

Invalid checksum
---------------------------
OK
---------------------------


so, how can I update my portable ffs?

edit: it seems that I have to activate again ...

The use of checksums [...] would not speed up the FFS comparison.

Correct, but performance with checksums is much worse: While FFS is comparing file content it breaks on the first byte difference found. Using checksums on the other hand would always require reading the full file content.


I ...

I join in asking to add an option in the settings to speed up the comparison using the checksum method (perhaps in the donations package along with the other options for performance?).
Open source projects using this approach are very fast:
https://github.com/arsenetar/dupeguru/
https://github.com ...

The zip file had an invalid checksum apparently. Still I couldn't reproduce the "Installer is damaged" error: the pkg was extracted fine on both macOS 12.3 and 10.15 (perhaps the error could be corrected by the extractor?). Fixed and re-uploaded.

... X) drive but did not create/delete any .jpg thumbnail files.

I think an improvement to the tool that can significantly speed up the processes is to create a checksum for each directory. If that checksum has not changed, then content of directory should be skipped for any update/mirror function.

Maybe the SMB protocol incorporates a checksum, I haven't checked.

Gotcha, that makes more sense, but is a little different than the original. Can't say for sure if that's how it's done or not

My point is that "Compare by Contents" should not be done on files of different size - they are different by definition.

Plerry isn't the dev, Zenju is, so he can't answer that question, I don't think. You say checksum is "just a concept" but then what is the point of your post??

Checksum is just a concept. Dou you compare contents of the files of different size?

The use of checksums is discussed many times (https://freefilesync.org/forum/search.php?keywords=checksum).
FFS does not use checksums. Using checksums also does not make sense for FFS, as FFS only runs in one location (which does not even need to be the left nor right location), and in order to ...

Comparison speed by checksum can improved drastically by calculating checksum only for the same path and file size. File size comparison is already implemented, just modify the algorithm by adding checksum to the same size files.

... Windows_Portable.zip
Size: 19,671 KB, alias 20,142,821 bytes
md5: cedf4dd86e8b63a4ed1f9623c8bd2166
So, size is the same as for therube ,
checksum obviously different, as these are donator specific files.

It seems your zip-file does not have the correct size (at 11,246KB).
Simply re-download ...