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 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 option.
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 Studio supports checksum algorithms such as xxHash, MD5, CRC, and SHA. The default, xxHash3-64, is the newest and fastest option. xxHash-128 takes longer to calculate but has a lower chance of checksum collisions. Your client or downstream workflow may also require a particular checksum type.
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. This can help identify issues caused by failing readers, overheating hardware, or faulty cables. It adds processing time and is only available when Full Checksum is selected.