HP StorageWorks 2/24 FW 07.00.00/HAFM SW 08.06.00 McDATA Products in a SAN Env - Page 146

Implementing SAN Internetworking Solutions 4 SAN Island Consolidation SAN islands tend to be constructed along application (such as product test, finance, or engineering), operating system (OS), protocol, or geographical (site-based) boundaries. Because of application and OS segmentation, large data centers at single sites often consist of SAN islands constructed with relatively small Fibre Channel switches. SAN Island Benefits A SAN island deployment strategy provides many benefits and may be sufficient to meet an enterprise's needs because: • SAN islands serve a purpose. The enterprise buys a switch, builds a simple fabric, and implements a SAN around a particular application. • Data, applications, and operating systems are isolated to their specific environment. • Failures do not cross SAN island boundaries. Fault isolation is limited to each SAN. • Firmware revisions are specific to each deployed SAN and do not have to be consistent enterprise-wide. • Specific functions (such as mission critical applications or test environments) are isolated and do not interact with or corrupt other functions. SAN Island Problems Implementation and management of isolated SAN islands has several problems, including: • A large number of fabric elements, storage devices, and servers to administer from several workstations, possibly using multiple SAN management applications. • No economy of scale to mitigate the costs of advanced fabric features. Sophisticated management applications must be purchased to administer each SAN. If high availability and non-blocking performance are required, director-class switches must be purchased for each SAN. • Complex interdependencies and data congestion because fabric switches are connected with multiple interswitch links (ISLs). A single low-cost edge switch can limit the scalability and performance of an entire fabric. 4-2 McDATA Products in a SAN Environment - Planning Manual