Veritas Volume Manager 5.0.1 Administrator's Guide, HP-UX 11i v3, First Edition, November 2009

The volume vol01 has the following characteristics:
It contains one plex named vol01-01.
The plex contains one subdisk named disk01-01.
The subdisk disk01-01 is allocated from VM disk disk01.
Figure 1-11 shows a mirrored volume, vol06, with two data plexes.
Figure 1-11
Example of a volume with two plexes
Volume with two plexes
Plexes
vol06-01 vol06-02
vol06
vol06-01 vol06-02
disk01-01 disk02-01
Each plex of the mirror contains a complete copy of the volume data.
The volume vol06 has the following characteristics:
It contains two plexes named vol06-01 and vol06-02.
Each plex contains one subdisk.
Each subdisk is allocated from a different VM disk (disk01 and disk02).
See Mirroring (RAID-1) on page 44.
VxVM supports the concept of layered volumes in which subdisks can contain
volumes.
See Layered volumes on page 52.
Volume layouts in VxVM
A VxVM virtual device is defined by a volume. A volume has a layout defined by
the association of a volume to one or more plexes, each of which map to one or
more subdisks. The volume presents a virtual device interface that is exposed to
other applications for data access. These logical building blocks re-map the volume
address space through which I/O is re-directed at run-time.
Different volume layouts provide different levels of availability and performance.
A volume layout can be configured and changed to provide the desired level of
service.
Understanding Veritas Volume Manager
Volume layouts in VxVM
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