Veeam Agent for Windows shows the following warning during the backup:
One or more bad blocks were detected and skipped
The NTFS file system stores information about bad blocks in a $BadClus metadata file.
More information about NTFS file system metadata can be found here.
Note: The $BadClus metadata file is backed up by Veeam Agent for Windows, if a bare-metal restore is performed to a new drive the $BadClus metadata is restored. To update the $BadClus metadata file run the command shown in the solution section of this article.
Run the following command for the drive that Veeam Agent for Windows displayed the error for.
Running this command will clear the list of bad clusters on the volume and rescans all allocated and free clusters for errors.
chkdsk volume_letter /b
Example: chkdsk C: /b
The warning shown within Veeam Agent for Windows is displayed if bad blocks are listed in the $BadClus metadata file. Therefore if the warning persists after running the command above, there are bad clusters on the drive.