Configuring checks for duplicates

There are two ways to check for duplicate files, one is on input and is set via the option dup_check under [dir options]. And the other is on output either for a single host (via HOST_CONFIG) or for a single job by setting dup_check under [options].
There are several ways one can do the check itself. The most common is on the file name. Doing it on the content of the file is also possible but takes longer and consumes more computer resources. The check itself is just a simple CRC32 checksum.
If a duplicate is detected there are several things one can do, the most common is to delete the file.