Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

Figure 1-4 shows a High Availability (HA) configuration where redundant-loop
access to storage is implemented by connecting independent controllers on the
host to separate switches with independent paths to the enclosures.
Figure 1-4
Example HA configuration using multiple switches to provide
redundant loop access
enc0 enc2
Host
Fibre Channel
switches
Disk enclosures
c1 c2
enc1
Such a configuration protects against the failure of one of the host controllers
(c1 and c2), or of the cable between the host and one of the switches. In this
example, each disk is known by the same name to VxVM for all of the paths over
which it can be accessed. For example, the disk device enc0_0 represents a single
disk for which two different paths are known to the operating system, such as
c1t99d0 and c2t99d0.
Note: The native multipathing feature of HP-UX 11i v3 similarly maps the various
physical paths to a disk, and presents these as a single persistent device with a
name of the form disk##. However, this mechanism is independent of that used
by VxVM.
For more information on administering native multipathing with Base-VxVM and
VxVM-Full, see the Veritas Volume Manager Release Notes.
See “Disk device naming in VxVM” on page 79.
See “Changing the disk-naming scheme” on page 99.
Understanding Veritas Volume Manager
How VxVM handles storage management
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