IBM Midrange System DS4000 Series Hardware Manual page 472

When using the device specific module (DSM) of the IBM Storage Manager together with
Microsoft's MPIO architecture, the device is represented under the Device Manager as shown
in Figure 7-89.
Figure 7-89 Device representation either using MPIO or SDDDSM
In the example presented in Figure 7-89, a DS5300 is configured with only one LUN. The
Access LUN is not mapped to the server. Therefore, we see in the Disk drives list only one
IBM 1818 Multi-path Disk Device that represents each logical drive mapped.
The physical paths are not represented, as was done with RDAC or Windows Server 2003 in
the past. The best practise to verify the paths is to use the SANsurfer or other HBA utilities to
verify the paths, as shown in Figure 7-86 on page 451.
However, there is also a way to gather this information in Windows. Figure 7-91 on page 455
shows the a way to get path details out of Windows tools. From the Windows Device
Manager, under Disk devices, right-click the MPIO disk that represents the DS5000 LUN, as
shown in Figure 7-90 on page 455.
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One MPIO multipath disk per LUN
Checks that MPIO driver is installed
Represents the HBAs installed
in the Server