| Adding additional disks to machines is a common task, especially since they are forever getting cheaper and users can easily find reasons to store larger amounts of data! It's less common to add additional tape drives; once one has been configured, it is usually kept until either it breaks or it just cannot back up enough data in the allowed timeframe. Nevertheless, it is a task that still needs performing and is carried out often enough to be useful to document the steps involved. In this chapter, we'll add a disk drive and a tape drive, but we'll do them as two separate tasks. First, to add the disk, we'll bring the machine down to the PROM level (the OK prompt) and start the tasks from there. After that, we'll add the tape, but this will be carried out while the system is up and running. This will allow us to show two methods of adding devices, but we need to remember that in the real world the second method will depend upon the hardware being used and may not be possible on all machines. This chapter ties in very closely with Chapter 6, "The Filesystem and Its Contents"; many of the commands described there have been used here. Both devices will be SCSI-based, chosen because it is the interface most commonly used in production-type environments. Before we start to add the devices, let's take a brief look at SCSI itself. | 
