Configuration at the host is supported through use of standard Microsoft Multipath I/O (MPIO) Windows Management Instrumentation (WMI) interfaces and persistence of the most recent load balancing setting at the host.
FSPM works with Microsoft MPIO to implement the MPIO WMI Classes. Refer to MPIO WMI Classes (http://msdn.microsoft.com/en-us/library/ff562468(VS.85).aspx) for details. FSPM does not use or support all aspects of these classes. FSPM implements two load balancing algorithms, while the WMI classes define more.
Windows Server 2008 R2 and later versions of Windows use these classes to implement extensions to various management applets. For example, the Device Properties applet associated with Oracle FS System LUNs displays an MPIO tab. The MIPO tab shows information from the WMI classes and enables modification of some fields. .
FSPM only allows certain fields to be modified. The Oracle FS System controls the optimization state of paths so path optimization state cannot be set from the host. Attempts to modify fields that FSPM does not control but which can be modified from the Device Properties applet do not fail. But settings not controlled by FSPM and modified with the Device Properties applet, are not changed within FSPM
The FSPM distribution includes a simple VBscript script (Scripts\lbset.vbs in the installation directory) as an example to access the WMI classes from scripts. To use this script, open a command prompt, change to the Scripts directory, and run cscript lbset.vbs. This script lists the current load balancing setting for all Oracle FS System and Pillar Axiom storage system LUNs accessible by the host, and then updates their settings to round-robin.
You may find this particular functionality useful, but the main purpose of this script is to illustrate how to access the WMI functionality from a script. You may copy and modify this script to implement whatever functionality you choose.
When a LUN is first discovered, the default setting is round-robin. The load balancing setting for LUNs can be configured at the Oracle FS System using the Oracle FS System Manager (GUI) or Oracle FS System CLI.
FSPM remembers the latest load balancing configuration at the host. When the host is rebooted, LUNs come online using the load balancing configuration most recently set.