I have an array of multiple drives primarily 3tb and 6tb with 6tb parity. One of my 3tb drives have failed, and i have bought 2 new 8tb drives. What is the right approach to this array upgrade without loosing any data?

 

Failed 3tb drive -> New 8tb drive -> rebuild new drive from parity -> swap parity drive from 6tb to 8tb -> build parity ->optional swap old 3tb drive with old 6tb parity.

Or should I copy content from failed 8tb drive to external drive and replace failed drive and parity drive at the same time...or perhaps another approach?

 

Tia

You cannot have any have any data drive that is larger than the smallest parity drive so your steps will not work!

 

The procedure to achieve what you want is the Parity Swap one that is covered here in the online documentation that can be accessed via the 'Manual' link at the bottom of the Unraid GUI.

 

You need to use the parity swap procedure.