HP XP External Storage Software - Manual (Page 32)

Figure 8 Alternate path mode is Single mode with alternate paths in Standby only
NOTE:
External arrays with Active/Standby (A/S) controllers, such as the MSA, are an example of
Figure 8 . A notable characteristic of using A/S controller arrays as external storage is that there
is typically only a single port to the owning controller. Paths to the non-owning external controller's
ports are shown as Standby status. I/O load balancing does not occur across external controllers.
Powering arrays on or off
This section describes procedures for powering local and external arrays on or off after External
Storage XP operations have started.
The procedures below will utilize the following commands:
• Disconnect Subsystem
Execute the Disconnect Subsystem command from the Command View XP or XP Remote Web
Console GUI when you need to perform maintenance or stop the local or external array. This
command stops acceptance of all host I/O operations to the external LU mapped as the internal
LDEV. All outstanding data in cache memory on the local array intended for the external LU is
written (de-staged) to the external LU.
For instructions on executing the Disconnect Subsystem command, see
Disconnecting external
arrays or LUs .
Preparing for External Storage XP operations 32