Used Drv means the SCSI channel 4 and 5 connected by your Hard drive
Used bad is to let you know that the harddisk attach to this drive is either damage o what.
you try to connect your “bad” hard dirve to another PC and see it really break down o just system faulty report it.
it also maybe your specific port of your scsi card or scsi cable got problem, you need to double check it.
hope this will help