volume add-brick: failed:
[2016-11-03 15:43:38.599713] E [glusterd-op-sm.c
glusterd_op_ac_stage_op] 0-management: Stage failed on operation 'Volume Add brick', Status : -1[SOLUTION]
The brick seems to have been added before already, and due to leftovers it refuses to join the cluster:
Add and remove GlusterFS servers (by Matt Sherborne)