SVS200 (T1714-96008, June 2006)

LUN Configuration and Security Manager XP user guide for the XP12000/XP10000/SVS200 21

After classifying server hosts into iSCSI targets, you must associate the iSCSI targets to logical volumes. In

Figure 3, the hg-lnx iSCSI target is associated with three logical volumes (00:00, 00:01, and 00:02). LU

paths are defined between the two hosts in the hg-lnx iSCSI target and the three logical volumes.

Figure 3 LU path configuration in iSCSI environments

Use LUN Manager to define paths between a single server host and multiple LUs. In Figure 3, both hosts in

the hg-lnx iSCSI target can access the three LUs.

Use LUN Manager to define paths between multiple server hosts and a single LU. In Figure 3, the LU

identified by CU-LDEV number 00:00 is accessible from both hosts belonging to the hg-lnx iSCSI target.

In Figure 3, LUs associated with the hg-lnx iSCSI target are addressed by numbers 0 to 2. The LU’s address

number is referred to as a logical unit number (LUN). When Continuous Access XP and other optional

programs manipulate LUs, the programs use LUNs to specify the LUs to be manipulated.

You can add, change, and delete LU paths when the system is operating. For example, if you add new

disks or server hosts to the array, you can add new LU paths. If you replace an existing server host, you

can delete LU paths corresponding to the host before replacing the host. You do not need to restart the

system when you use LUN Manager to add, change, and delete LU paths.

If a hardware failure (such as a CHA failure) occurs, some LU paths might be disabled and some I/O

operations might be stopped. To avoid this situation, the system administrator can define alternate LU

paths. If one LU path fails, the alternate path takes over the host I/O.

For more information, see: