HP Hitachi Dynamic Link Manager Software - Manual (Page 33)

2. HDLM Functions
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2.2.2 System Configuration Using an IP-SAN
In an IP-SAN, LAN cables are used to connect hosts to storage systems. The cable port
on the host is called a network interface card (NIC). In order to use an NIC, the iSCSI
software must be installed ahead of time on the host. The cable port on the storage
system is called a port (P) on a channel adapter (CHA) used for iSCSI connections.
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.
Figure 2-2: Configuration of an HDLM System When Using an IP-SAN shows the
configuration of an HDLM system using an IP-SAN.
Path A route that connects a host and a Dev.
Components Description