I think I painted myself into a corner.  Unraid 6.12.2. 

Short question:  Can I replace a failed data disk in a single parity with a disk bigger than the parity disk?  e.g. rebuild the array using only 2 TB of a 4 TB drive?  (I think the answer is the parity disk ALWAYS needs to be the biggest).

 

Background:

I have a 6 TB array with a single parity; i.e. 3 x 2 TB data disks + 1 x 2 TB parity disk. I had 1 x data disk die on me. I purchased a 4 TB disk because... The WD Reds are nearly the same price for a 2 TB as a 4 TB.  However, the GUI is prohibiting me from hitting "start" after I removed the failed 2 TB drive and replace it with the 4 TB because

If this is a new array, move the largest disk into the parity slot.
If you are adding a new disk or replacing a disabled disk, try Parity-Swap.

 

 

How can I get up and running at this point?  Is this the best path to go down:

1. Copy the current 2 TB parity disk onto the new 4 TB drive (how do I do this??). 
2. THEN use the 2 TB parity disk as a data disk, keeping the 4TB disk as the new Parity. 
3. Rebuild from here. (now with a 4 TB parity in case of future upgrade)

 

Sorry, sorry, sorry.  Clearly spelled out as a "3 drive parity shuffle" in the FAQ:  https://docs.unraid.net/legacy/FAQ/parity-swap-procedure/

22 minutes ago, mattz said:

Sorry, sorry, sorry.  Clearly spelled out as a "3 drive parity shuffle" in the FAQ:  https://docs.unraid.net/legacy/FAQ/parity-swap-procedure/

Probably better to refer to this section of the online documentation accessible via the ‘Manual’ link at the bottom of the GUI or the DOCS link at the top of each forum page. The Unraid OS->Manual section in particular covers most features of the current Unraid release.    It is better to use the documentation for the current release rather than legacy documentation that may no longer be valid.