Logical unit settings for the Hitachi TagmaStore AMS 2000 family of systems

Logical unit (LU) settings apply to individual LUs that are configured in members of the Hitachi TagmaStore AMS 2000 family of systems.

You must configure the systems LUs as described in Hitachi TagmaStore AMS 2000 family of systems LU settings for the system if the logical unit number (LUN) is associated with ports in a switch zone that is accessible to the system.

Table 1. Hitachi TagmaStore AMS 2000 family of systems LU settings for the system.
Option	Default setting	Required system setting
LUN management information
Security	Off	Off Note: LUN Security enables LUN masking by the worldwide node name (WWNN) of the initiator port. This function is not supported for logical units (LUs) that are used by the system.
LU mapping	One-to-one	One-to-one
LAN management options
Maintenance port IP address automatic change mode	Off	Off
IPv4 DHCP	Off	Off
IPv6 address setting mode	Auto	Auto
Negotiation	Auto	Auto

Note: These settings apply only to LUs that are accessible by the system.

Data corruption scenarios to avoid

Scenario 1: You use the configuration application to change the serial number for an LU. Changing the serial number also changes the unique user identifier (UID) for the LU. Because the serial number is also used to determine the WWPN of the controller ports, two LUNs cannot have the same unique ID on the same SAN because two controllers cannot have the same WWPN on the same SAN.

Scenario 2: The serial number is also used to determine the WWPN of the controller ports. Therefore, two LUNs must not have the same ID on the same SAN because this configuration results in two controllers that have the same WWPN on the same SAN. This configuration is not valid.

Attention: Do not change the serial number for an LU that is managed by the system because this change can result in data loss or undetected data corruption.

Scenario 3: You use the configuration application to create LUN A, delete LUN A, and create LUN B with the same unique ID as LUN A. If the LUN is managed by the system, this scenario can cause data corruption because the system might not recognize that LUN B is different than LUN A.