How can I make Duplicacy ignore errors like "Data error (cyclic redundancy check)", without failing the whole backup due to one such error?

Support
,
#1

The backup of one of my storages always fails because of a " Data error (cyclic redundancy check)" error of a specific file (always the same file). That file is simply broken, I also can’t use it in the windows explorer. I don’t care about the file, so I’d like Duplicacy to simply ignore the error and skipping the backup of that one file, maybe warning me at the end that it could not backup one specific file - but what Duplicacy is doing is stopping the whole backup process once it encounters such a file.

ERROR CHUNK_MAKER Failed to read 0 bytes: read [FilePath]: Data error (cyclic redundancy check).
Failed to read 0 bytes: read [FilePath]: Data error (cyclic redundancy check).

The last time it actually succeeded a backup was 3 months ago or so - that’s obviously quite bad, it shouldn’t stop doing backups for 3 months just because one file is broken.

#2

While you can simply add exclusion pattern for this file so that it is ignored by :d:, I’d rather try to resolve the original issue. Error like that indicates that either your drive is failing, or filesystem is not in a consistent state. Neither is good, and may impact other files even if you don’t care about this particular one. I’d run maximum chkdsk (if you’re on Windows) and see if this fixes the underlying issue.

The error is pretty bad, so I am not sure :d: should ignore it and just continue.

#3

Worst case scenario, you could move that file out of the way - put it in \temp, say - and just don’t back it up. You might even be able to restore a copy of the file from previous backup, before it got corrupted.

Once you have a new backup, you should definitely scan for bad sectors and evaluate the integrity of the disk with SMART and other tools.

#4

I agree I should work on fixing the underlying issue that causes a file to become corrupted in such a way.

But since I haven’t been able to backup this drive for over 3 months by now since Duplicacy stops at the beginning of the process when encountering that file, I think it definitely makes sense to first make sure that my Duplicacy backup of all the remaining files can actually run successfully before I fiddle with the drive in any way.

It is not just one file that has the issue, I checked with another tool that it’s a few dozen files in total. Duplicacy just always fails when it encounters the first such file. “Moving” such a file does not work, it can’t be copied due to the issue. I can restore affected files from my Duplicacy backup, but doing that for a few dozen files would be a lot of work.

So the question at the moment is just how can I make Duplicacy backup my other 99.9999% of working files without stopping once it encounters some of the 0.00001% files that are broken?

#5

You will need to exclude all these files from backup, this would be under Include/Exclude if you’re using the GUI.

1 Like
#6

Thanks, I guess that is indeed a solution!

Though I’d still prefer some kind of “treat errors as warnings” option or whatever similar so that I don’t need to manually add all those exclude files.

#7

Is there an option for ignoring errors in the latest version? I have a failing drive with a few thousand files (out of a million or so) that will have read errors. If I run chkdsk, it will make matters worse. Can I get Duplicacy to backup all the files that are readable?

#8

Duplicacy isn’t a data recovery program - you should be using the best tools for the job i.e. HDDSuperClone or ddrescue - to get as much data off the drive as possible, onto a good drive. (You could combine HDDSuperClone with DMDE to target the files you’re most interested in.)

Or seek out a data recovery company if your data is really important to you. Otherwise, stop using the drive with Duplicacy, as the more you use it the more damage you’re likely making to the physical platters.