Chapter5.Storage Subsystems

Chapter 5. Storage Subsystems

Upon completing this chapter, you will be able to

• Identify the major architectural components used in a storage subsystem

• Participate in discussions with coworkers, vendors, and analysts about the strengths and weaknesses of designs used in storage subsystems

• Analyze the functions and features provided by a storage subsystem, including its capabilities for high-availability environments

• Participate in planning exercises concerning the connections used between systems and storage subsystems

Storage networks tend to be designed using storage-centric architectures. Obviously, the storage at the core of such designs should be flexible, scalable, and robust. In most storage networks this is accomplished by implementing storage subsystems that combine storage devices with intelligent storage controller, network, and power technologies. Just as computer systems span an enormous range of prices and capabilities, storage subsystems range from fairly simple products that resemble enhanced storage devices to those with enormous processing power and sophisticated data protection applications and management capabilities. This chapter examines the technologies, architectures, and implementations that are commonly found in this important product category.

NOTE

The analysis in this chapter views storage subsystems primarily as storing products, meaning that network-attached storage (NAS) systems are not explicitly discussed. For those NAS lovers out there who feel shortchanged, don't feel slighted. NAS systems are often used as core infrastructure storage products, and they all use some type of disk subsystem for their storage. The topics discussed in this chapter apply to the storage part of NAS servers the same way they apply to storage area network (SAN) subsystems.