Working with parity files.
In some cases if you download large archives of files, the archive is corrupted and you can’t extract the files. For that reason some provide additional parity files (like a disk raid creates parity data from the real data).
Create Parity Files
If you plan to share a big archive, create parity files for downloaders to be able to repair the archive if it’s corrupted after download. No need to download the full archive again and which might be broken again.
By default par2 creates 5% of parity.
par2create myBigArchive.par2 myBigArchive.part*.rar You can create parity files with more as 5% parity.
To achieve this use -r parameter and give percentage as value
par2create -r15 myBigArchive.par2 myBigArchive.part*.rar Use Parity Files
If a downloaded archive is broken and you have parity files, repairing the archive is easy.
par2repair myBigArchive.par2Prior to that you are able to check if a repair is necessary by
par2verify myBigArchive.par2