System configuration using an FC-SAN

In an FC-SAN, fiber cables connect hosts to storage systems. The cable port on the host is a host bus adapter (HBA). The cable port on the storage system is a port (P) on a channel adapter (CHA).

A logical unit (LU) contained in a storage system is the target of input to, or output from, the host. You can divide an LU into multiple areas. Each area after the division is called a Dev. The Dev is equivalent to a partition. A route that connects a host and an LU is called a physical path, and a route that connects a host and a Dev is called a path. When an LU has been divided into multiple Devs, the number of paths set to the LU is equal to the number that is found by multiplying the number of physical paths by the number of Devs in the LU.

HDLM assigns an ID to a physical path and manages the paths on a physical-path basis. When you use HDLM, there is no need to consider the difference between a physical path and a path. Thus, hereafter both physical paths and paths might be called paths, without a distinction being made between the two. The ID that HDLM assigns for each physical path is called an AutoPATH_ID. Also, a path might be called a management target.

The following figure shows the configuration of an HDLM system using an FC-SAN.

The following table lists the HDLM system components when using an FC-SAN.