Error adding USB to boot pool (to mirror boot USB)

[NigelNoFriends]

'gpart create -s gpt -f active /dev/da1' failed: gpart: arg0 'da1': Invalid argument'

This is the error I get after a minute or so.

Have tried ext and dos to format drive before adding to pool. USB is fine - i.e. working. It is exactly the same USB as main boot USB (same make, model, and capacity etc.)

Have you provided the information requested in this guidance :Updated Forum Rules 12/5/18
https://forums.freenas.org/index.php?threads/updated-forum-rules-12-5-18.45124/

Code:

motherboard make and model: ASROCK FM2A288X-ITX+
CPU make and model: AMD A10-7860K Radeon R7, 12 Compute Cores 4C+8G 
RAM quantity: 16GB
hard drives, quantity, model numbers, and RAID configuration:5TB Seagates, x4, STDR5000103, raidZ
hard disk controllers: built-in SCSI controllers?
network cards: Qualcomm Atheros AR8171
shoe size: 13.5
freenase build: FreeNAS-11.2-U2.1 

 

[Chris Moore]

Have you provided the information requested in this guidance :

Updated Forum Rules 12/5/18
https://forums.freenas.org/index.php?threads/updated-forum-rules-12-5-18.45124/