I was just reading and found this:
Option 1
Assign ALL drives as data drives.
Start the array
Make a note of the serial numbers of drives showing as unmountable as these are probably our parity drives.
Option 2 If you have the Unassigned Devices plugin installed then:
Try to Mount each drive in turn to see which ones fail to mount.
Make a note of the serial numbers of drives showing as unmountable as these are probably our parity drives.
Now that you have identified the parity drives then:
Go to Tools -> New Config and select the option to create a new array configuration. This time it is advisable to use the option to retain all currently configured drives as this avoids the need to rearrange all drives (and thus reduces the chances of error.
Go to the Main tab and assign the drives as required with the correct drive(s) assigned as parity.
If you only had a single (parity1) drive then the order of the data drives is not important as far as parity is concerned so you can probably safely tick the "Parity is Valid" checkbox. With dual parity then since the parity and parity '2 drives use different calculations they are not interchangeable so you will need to generate parity from scratch on both drives.
Start the array to commit the drive assignments and you should see all your data drives have mounted and their contents are intact.
If you ticked the "Parity is Valid" checkbox then run a correcting parity check to make sure this was a valid assumption.
The above process will not necessarily mean the data drives are in the same order so you have any shares that have specific drive include/exclude then you will need to look at the contents of the individual data drives to make sure these are as you want them (and correct them if not)
So it looks like I just need to recreate the parity on the drives? I've assigned them correctly and it's recreating parity now. I am pretty sure that'll be okay, It looks like everything else is in place.