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CRC (Cyclical Redundancy Checking)

CRC is the acronym for Cyclical Redundancy Checking.

It is a type of algorithm known as a "hash". A hash algorithm accepts variable-length input and produces a fixed-length output which uniquely represents the input data. The hash is usually much shorter in length than the data it represents. A sample CRC value for a file could be ADE50E9F. In theory, no other file should produce the same hash value. ViceVersa calculates the CRC value of one file and compares it to the CRC of the corresponding file in the other folder. If the CRCs differ, the files differ. The CRC algorithm is widely used in network protocols and compression programs.

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Winton Kinson -  09-Mar-05
If the source and destination CRCs match (the files ARE identical), but the timestamps are different, will ViceVersa re-copy the file or can it just update the timestamp?
TGRMN Software -  13-Mar-05
It depends on the comparison method selected. If "Both" was selected, ViceVersa will consider the files as different and overwrite the older file with the newer file. If "CRC only" comparison method was selected, ViceVersa will consider the files identical and will not change anything.
Matt -  02-Apr-06
What type of CRC Check is performed, 16 or 32?
TGRMN Software -  12-Apr-06
Ivan -  17-Oct-06
When using CRC only Sync : if a file in a subfolder changes the program does a complete CRC re-check (among all the folders) or it only compares the single file/folder? (since the CRC calculation takes so long to complete i'd like to know the reaction time between a change in a file and the copy across the network to the destination folder).
TGRMN Software -  24-Oct-06
When re-scanning source(s) and target(s) all files are re-compared using CRC.
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Author: TGRMN Software

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