Looks like you're running 7mode 8.x something.
With that many unassigned disks I would check to see if all of your aggregates are healthy. I don't think there's actually a way to assign disks in the 7mode gui..
run "aggr status" on each controller. If there are any aggrs that are showing degraded I would assign disks to whatever controller they are on. If they're all good, make sure each controller has approximately the same amount of shares.
run "disk assign diskid" on the controller you want to own the disk.
"aggr status -s" will allow you to see what spares are already assigned.