I have two parity drives. I want to upgrade my parity drive size from 8TB to 16TB drives.  I bought two new 16TB drives, which are being pre-cleared as we speak. I know that parity drives needs to be at least the same size as my largest disk (8TB) in my array but do the parity drives need to be the same size? If they can be different sizes, should I just replace one and do a rebuild or would you recommend replacing both at the same time and doing a rebuild? Any downsides or upsides to either approach.

 

Also.... is there a recent guide (7.0.0) for replacing parity drives?

You can just upgrade one, but won't be able to add any data disks larger than the other parity to the array, until you also replace the other.

How dangerous is it to replace both at the same time compared to doing one at a time?

If you do it in maintenance mode and keep the old parities intact, you can go back to the old ones if needed, if you need the array online, it may be better to do it one at a time.

Is there a document outlining the steps for swapping out the parity drive? I found one online but it is outdated.

Is this all I need to do because my new parity is larger than any other drive I have?

 

Just stop the array, unassign the parity drive and then remove the old parity drive and add the new one, and start the array. The process of building parity will immediately begin. (If something goes wrong, you still have the old parity drive that you can put back!)

15 minutes ago, stepmbac said:

Is there a document outlining the steps for swapping out the parity drive? I found one online but it is outdated.

Were you looking at the 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via the ‘Manual’ link at the bottom of the GUI or the DOCS link at the top of each forum page as this should not be outdated.   The Unraid OS->Manual section in particular covers most features of the current Unraid release.