HP Network Storage Router m2402 - Manual (Page 53)

Configuration Overview
59 Network Storage Router M2402 User Guide
(16 and up, for example). This situation can be resolved by configuring the router
to use hard addressing and setting the AL_PA to a value less then 16 that the HBA
will be able to map.
For example, depending on the FC HBA, if the hard AL_PA selection is 1, then
the address is 1. If the selection is 125, the AL_PA address is 0xEF. Some FC
HBAs will map devices differently, so verify the AL_PA by reviewing the
documentation for the HBA.
Logical Unit Management
Because SAN resources can be shared, it is possible for multiple hosts to have
access to the same devices on the SAN. To prevent conflicts, the router provides
LUN management as a means to restrict device access to certain hosts. LUN
management goes beyond simple LUN masking, to prevent gaps in the list of
LUNs presented to a host.
LUN management maps can be created for different views of the devices attached
to the router. Each FC host is assigned a specific map configuration. Not only can
the administrator control which devices a host may access, but also which LUNs
are used to access these devices.
For a FC host, a map is a table of LUNs, where each entry is either empty or
contains device address information needed for host/device communication.
For a SCSI host, a map contains a list of target IDs, each of which has its own
table of LUNs with address information needed for host/device communication.
Note: The router can respond to multiple Target IDs on a SCSI bus.
Both FC ports and SCSI buses have user-defined maps and pre-defined maps.
There are three predefined maps:
■ Indexed (default)
■ Auto Assigned
■ SCC
When a host sends a command, the router will select which map to use, based on
the port receiving the command and the ID of the host sending the command. For
FC ports, the host ID is the World Wide Name and for SCSI buses, the host ID is
the Initiator ID (0 - 15). When a host is unknown or is not assigned a specific map,
the router will use the default map.