HP StorageWorks XP Remote Web Console Software - Manual (Page 26)

HP recommends configuring alternate paths for safer operation and increased bandwidth. For
instructions, see
Setting alternate paths for external LUs .
You can set alternate paths when the external LUs are mapped as the internal LDEVs (see Mapping
external LUs (Add LU) ). You can also set alternate paths after completing the mapping operation (see
Setting alternate paths for external LUs ).
Example of an alternate path configuration
Figure 2 shows an example of an alternate path configuration. In Figure 2 , external array ports WWN
A and WWN B are connected to CL1-A and CL2-A, respectively, which are designated as external
ports in the local array. You must specify the port of a different cluster in the local array for the alternate
path, as ports CL1 and CL2 are specified in the figure.
Figure 2 Example of alternate path configuration
.
Figure 3 shows another example of an alternate path configuration. In Figure 3 , two ports are specified
in the local array and connected to ports in the external array via switches. In this example, two ports
from different XP12000/XP10000/SVS200 clusters are specified in the local array, thereby making
it possible to configure an alternate path for high availability.
Figure 3 Example of alternate path configuration using two switches
.
In Figure 4 , two paths are configured between the internal LDEV and external LU. However, only one
port is specified in the local array and two ports are specified in the external arrays via the switch.
Since two ports of different clusters must be set in the local array for XP External Storage to use alternate
path settings, HP does not recommend the configuration shown in
Figure 4 .
Preparing for XP External Storage operations 26