Will try formattting with the default option once I get past a new password problem:-
"The operation to unmap or delete volume ses_array_vol_01 failed. The operation cannot be completed because you did not provide a valid password. Open the Storage System's folder in the left hand navigational tree, click on the Administration folder, then click on Manage passwords and provide a valid Storage System password."
I have no idea what the valid storage system password would be, I never set one.
Nevermind it's nearly the weekend.
DD
Update -
After a few minutes, I went to the Administration (Manage Passwords...) again, and I filled ONLY the fields (New Password, and Verify New Password), leaving the OLD password field (which is REQUIRED), blank. And I got a Success !!! blue i , great.
Reformatting array with default filesystem now... will try mounting the array again on Monday morning.