This counter tracks how many SCSI 'Busy' status responses this flow's initiator has received from the target, meaning the target was temporarily unable to accept the command. An admin seeing this climb on a specific flow should suspect that the target LUN or array controller is overloaded relative to the traffic this particular host is sending it, which can manifest to end users as intermittent slow I/O rather than outright errors. A flow showing a steady trickle of busy statuses during the target array's known peak backup window would correlate the symptom directly with that scheduled load.