I'm trying to add a new disk to the array the same way I've done before and this is the error that appears in the GUI. 

 

You may not add new disk(s) and also remove existing disk(s)

 

I can add it as a parity disk, I can add it as a cache disk but when I try to add it to the array I get the above message. I have a sufficient licence for the number of disks in the array. 

 

 

EDIT: I've worked around this by making my existing parity drive a storage drive in the array and making the new drive the parity. 

Edited December 14, 20178 yr by Fpsware

You can not add it as a data disk when its size is bigger than the parity disk. The parity disk must be the biggest or at least as big as the biggest data disk.

 

 

I'm aware of this, they are both 2Tb drives.  In fact, 3 other drives in the system are the same make and model number as the drive I'm trying to add. 

Edited December 14, 20178 yr by Fpsware