What is a necessary step before connecting an external SCSI hard drive to a system?

Before connecting an external SCSI hard drive to a system, setting the drive's SCSI ID is a necessary step. SCSI (Small Computer System Interface) operates in a specific way that requires each device on the SCSI bus to have a unique identifier known as a SCSI ID. This ID allows the system to differentiate between multiple connected SCSI devices.

When connecting multiple SCSI devices, if they share the same SCSI ID, the system will not be able to communicate effectively with them, leading to conflicts and potential data loss. Thus, configuring the SCSI ID correctly before connecting the drive ensures that the operating system can detect and manage the hard drive properly without any conflicting device addresses.

In contrast, while formatting the drive, updating the operating system, and installing device drivers may be important steps during setup or configuration of storage devices, they are not prerequisites for the actual connection of the SCSI hard drive. Formatting typically occurs after the drive is connected and detected by the system, ensuring that it is ready for data storage.