Does anyone remember Parchive? back in the usenet days, Par was used to recover corrupted or missing data from Usenet block.  The nice thing about Par was that it would use the file(s) themselves to create a parity and would only require the number of blocks to replace the missing data. Hypothetically speaking if you had a 20GB file had a 4k corruption within that file you would only need a 4k par file to repair the original file (assuming the bad data was on in same block). I was cool tech back then, and I and surprised that it never when anywhere.

 

I was just curious what people think. I could see a background task that would reserve 1%-10% of each drive to create a Par set per file at 4K per block.
sure the initial calc would be long, but considering that the majority of data never changes, and that this could be done on a per file basis I could see this as a way to adding partial a functionality of a Q disk with needing a second drive,

 

Just my 2 cents.

It is still a good idea. Some people think this is redundant, but more backup is not redundant and in many cases it will come in handy. 

 

For example, if you send a set of files to other people, then you can include the par file. 

You can not send your parity data on your parity drive to other people.