Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Chapter 3, Administering Dynamic Multipathing (DMP)
How DMP Works
103
How DMP Represents Multiple Physical Paths to a Disk as One Node
As described in “Enclosure-Based Naming” on page 6, VxVM implements a disk device
naming scheme that allows you to recognize to which array a disk belongs. The figure,
“Example of Multipathing for a Disk Enclosure in a SAN Environment” on page 103,
shows that two paths, c1t99d0 and c2t99d0, exist to a single disk in the enclosure, but
VxVM uses the single DMP node, enc0_0, to access it.
Example of Multipathing for a Disk Enclosure in a SAN Environment
See “Changing the Disk-Naming Scheme” on page 72 for details of how to change the
naming scheme that VxVM uses for disk devices.
Single DMP Node
Multiple
Paths
DMP
VxVM
Mapped by DMP
Multiple
Paths
Host
Disk
c2c1
Host
Fibre Channel
Hubs/Switches
Disk Enclosure enc0
enc0_0
DMP
VxVM
Mapped by DMP
c1t99d0 c2t99d0
c2c1
Disk is c1t99d0 or c2t99d0
depending on the path