[Dayhike Mike]

QuickPar is definitely the utility to use for PAR2 creation. Each block of the parity files have checksums so that they can verify their own integrity. If you have corrupt parity blocks, those are just marked non-usable by QuickPar and you'll have to track down additional parity blocks in order to recover the missing / corrupted files. I haven't really dinked around with creation of parity files all that much, though. Just an avid user of those created by others. Do know that you should make sure and check the Integrate QuickPar into Shell in order to be able to right-click on a set of selected files and build a PAR set for them, but there's likely other ways as well. Good luck!

[MCaver]

QuickPar is what you need for PAR2. I recommend associating it with PAR2 extensions as well as integrating into the shell, both selected from he options menu. Shell integration allows you to right-click a group of selected files and create parity files for them. Much faster than going into the UI every time. Each PAR2 file contains some number of recovery blocks. I believe it's the second number in the filename, after the plus. There is a variable amount I assume because you may only need 3 blocks instead of 15 (for example) and would only have to download the smaller parity file over the Intenret (these are used a lot in downloading binaries). You only need as many parity blocks as you have corrupted blocks, so it's only a big deal if one of your parity files gets corrupt if you then don't have enough parity blocks to recover the corrupted data. Oops, didn't see DH's reply until I posted mine. The easiest way I've found to create your own parity files is it integrate QuickPar into the shell, right-click them , then select the files you want to create parity blocks for, then select "Create Recovery Volumes" under the QuickPar menu. This will launch the QuickPar UI for the selected files. Set the source block count ad source size, then click Create. You can also set a default block size in the options, which will set the block count for you based on that size as long as it's between 200 and 3000. This means you usually only have to right-click->create volumes->create as long as you aren't working on a very small or very large selection.

[Tom]

I am using the shell but it seems like you can't quickly add entire folders and subfolders. Kind of a pain for backup purposes. Or is there an easier way of doing this?

[MCaver]

Neither par nor par2 support subdirectories. I think QuickPar will allow you to put files in subdirectories, but that's a feature of the software, not the par2 standard. The file names have to be unique among all directories though, otherwise it gets confused. I ended up making pars for every directory individually.