TLDR: I need to promote an 18TB array drive as a 2nd parity, and replace it on the array with a smaller 14TB drive.
Short story long...
I purchased 2x 18TB drives last year. I did the "parity swap" dance with a 12TB drive.
Instead of being actually smart and adding the other 18TB drive as a 2nd parity right then and there, I didn't. (to be fair, I was waiting on a HDD caddy for more mounting space)
Fast forward to one of my 6TB array drives failing a few months later, so I panic-swapped it to my only spare drive, the other 18TB, so my kids could continue to watch their precious Coco on repeat on Plex.
I picked up 2x 14TB drives during the holiday sales.
I'd like to now replace the 18TB array drive with one of the new 14TB drives, so I can utilize the 18TB as a secondary parity drive. However, I find myself a little stuck not being able to replace the 18TB array drive with anything smaller (understandable)
From my understanding, the failed drive or disk swap parity dance doesn't really apply since I would be reducing the total size of the array, but surely there's a "safe" way to accomplish this? TIA!