What is the difference between File Size Only, File Size – Source Checksum, and Full Checksum?

- File Size Only: Compares the sizes of source and copied files. This is the fastest option, but it does not use checksum comparison.

- File Size – Source Checksum: Calculates checksums from the source files and includes them in reports, but does not read the copied files back to compare their checksums.

- Full Checksum: Reads the copied files back, calculates their checksums, and compares them with the source values. This is the most thorough of the three options.

The manual notes that only Full Checksum verification can ensure that the bytes read from the destination match the bytes read from the source.

Which checksum type should I use?

ShotPut Pro supports checksum algorithms such as xxHash, MD5, CRC, and SHA. The default, xxHash3-64, is designed for speed. xxHash-128 takes longer but reduces the chance of two different files producing the same hash value. If a client or downstream system requires a particular checksum type, select the required option.

What is Source Integrity Verification?

Source Integrity Verification reads the source media a second time at the end of a backup session to check whether its contents have changed since the initial read. It can help identify problems such as intermittent reader or cable failures, but adds extra processing time. This option is available only when Full Checksum is selected.

What is an MHL seal?

A Media Hash List (MHL) records file paths and checksum information that can be used by downstream workflows to check whether copied files still match their original contents. Enable MHL generation in Report Preferences if you want to create these files with your copies.