Have I done my snapraid right?

To preface this I am completely new to linux, OMV, Unionfs and Snapraid.
So I have 4x2tb drives, I have merged 3 of them and set up snapraid in raid 5 like configuration 3 data drives 1 parity, I just put over 550gbs of data all of this was placed onto 1 of my 3 drives (thats how unionfs distributed it) then ran a sync, now my parity drive is filled with 550gb of data, Have I done something wrong? What will happen when I fill up all 3 drives I thought Parity data was calculated differently so shouldn't 1:1 ratio, Can some explain this to me or have I just done something wrong. See images below!

Zitat von gderf

Your setup is correct. The size of the parity file will be as large or slightly larger than the size of the data on your most filled up drive.

Okay I have only ever used hardware raid and that was 7+ years ago, so what happens when all 3 drives are filled how does the 4th drive handle that can it still restore any of the 3 other drives if one fails?

Zitat von gderf

As I said, the size of the parity file will be as large or slightly larger than the size of your most filled up drive, regardless how many data drives you have. This is why the parity drive must be at least as large as your largest data drive.

With one parity drive you will be able to fully recover one failed drive assuming the parity file, content file, the config file, and all the other non-failed data drives are present.

I am going to be expanding this array in the future would it be worth getting bigger drives just for parity then? My original plan was 8x2tb drives + 1 10tb
drive 5 2tb data drives and then 3 2tb parity drives and 1 10tb for backup of the 5x2tb drives.

With what you said it might be worth getting slightly bigger parity drives and switch out the current 2tb parity for 6tb parity.
So now I am thinking 6x2tb for data 2x6tb for parity and 1 12tb to backup the data.