EMC CX500I Configuration Guide - Page 25

About CX300, CX500, CX500i, and CX700 Storage Systems Types of Storage-System Installations You can use a storage system in any of several types of installation: ◆ Unshared direct with one server is the simplest and least costly. ◆ Shared-or-clustered direct, with a limit of two servers, lets two servers share storage resources with high availability. ◆ Shared switched, with two switch fabrics, lets two or more servers share the resources of several storage systems in a storage area network (SAN). Shared switched installations are available in high-availability versions (two HBAs per server) or with one HBA per server. Shared switched storage systems can have multiple paths to each SP, providing multipath I/O for dynamic load sharing and greater throughput. Unshared Direct Shared or Clustered (One or Two Servers) Direct (Two Servers) Server Server Server Shared Switched (Multiple Servers, Multiple Paths to SPs) Server Server Server Adapter Adapter Adapter Adapter Adapter Adapter Adapter Adapter Adapter Adapter Adapter Adapter Server Component Interconnect Component FC Switch or LAN FC Switch or LAN Storage SP A SP B Component Storage System SP A SP B Storage System SP A SP B SP A SP B SP A SP B Storage System Storage System Storage System Path 1 Path 2 Figure 1-9 Types of Storage-System Installation EMC1826a Storage systems for any shared installation require EMC Access LogixTM software to control server access to the storage-system LUNs. The shared-or-clustered direct installation can be either shared (that is, use Access Logix to control LUN access) or clustered (without Access Logix, but with operating system cluster software controlling LUN access). Types of Storage-System Installations 1-13