In the case where {HEAD ~ time} of twenty four hour clock is registered in {TAIL ~ the “diagnosis start time}” 270, the diagnosis of the spare magnetic disk unit 191 may be conducted when the registered time has been reached 
In the case where { HEAD ~ time } of twenty four hour clock is registered in { TAIL ~ the “ diagnosis start time } ” 270 , the diagnosis of the spare magnetic disk unit 191 may be conducted when the registered time has been reached
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH