Mapping and virtualization settings for the Hitachi TagmaStore AMS 2000 family of systems

The Hitachi TagmaStore AMS 2000 family of systems supports different modes of operation. These modes affect LUN mapping or masking and virtualization.

Attention: The Hitachi TagmaStore AMS 2000 family of systems does not provide an interface that enables the system to detect and ensure that the mapping or masking and virtualization options are set properly. Therefore, you must ensure that these options are set as described in this topic.

S-TID M-LUN modes

In S-TID M-LUN mode, all LUs are accessible through all ports on the system with the same LUN number on each port. You can use this mode in environments where the system is not being shared between a host and the the system.

M-TID M-LUN modes

If a system is shared between a host and the system, you must use M-TID M-LUN mode. Configure the system so that each LU that is exported to the system can be identified by a unique LUN. The LUN must be the same on all ports through which the LU can be accessed.

Example

The system can access controller ports x and y. The system also sees an LU on port x that has LUN number p. In this situation, the following conditions must be met:

The system must see either the same LU on port y with LUN number p or it must not see the LU at all on port y.
The LU cannot appear as any other LUN number on port y.
The LU must not be mapped to any system port that is zoned for use directly by a host in a configuration where the system is shared between a host and a clustered system.

M-TID M-LUN mode enables LU virtualization by target port. In this mode, a single LU can be seen as different LUN numbers across all of the controller ports. For example, LU A can be LUN 0 on port 1, LUN 3 on port 2, and not visible at all on ports 3 and 4.

Important: The system does not support this option.

In addition, M-TID M-LUN mode enables a single LU to be seen as multiple LUN numbers on the same controller port. For example, LU B can be LUN 1 and LUN 2 on controller port 1.

Important: The system does not support this option.