Summary

SCSI technology is fundamental to storage networking. While the physical SCSI bus is not commonly used to transport data in SANs, it is still used in NAS systems and server systems for local storage. More importantly, the logic of SCSI can be thought of as the storage application in SANs.

This chapter discussed the logical structures of SCSI, describing the key elements that are involved, including initiators, targets, logical units, LUNs, device servers, and task managers. The client/server nature of SCSI communications was discussed, along with some insight into how this impacts server operating system processes. Other topics included worldwide names used in SANs and advanced SCSI features, such as tagged command queuing and extended copy operations.