VERITAS Volume Manager 3.1 Administrator's Guide

Introduction to Volume Manager
Virtual Object Data Organization (Volume Layouts)
Chapter 138
Virtual Object Data Organization (Volume
Layouts)
Data in virtual objects is organized to create volumes by using the
following layout methods:
• concatenation
• striping (RAID-0)
• RAID-5 (striping with parity)
• mirroring (RAID-1)
• mirroring plus striping
• striping plus mirroring
The following sections describe each layout method.
Related Graphical User Interface (GUI) Terms
The following graphical user interface (GUI) terms refer to types of
layered volumes created on the Storage Administrator:
• Concatenated Pro —a layered concatenated volume that is
mirrored
• Striped Pro —a layered striped volume that is mirrored
Concatenation
Concatenation maps data in a linear manner onto one or more subdisks
in a plex. To access all the data in a concatenated plex sequentially, data
is first accessed in the first subdisk from beginning to end. Data is then
accessed in the remaining subdisks sequentially from beginning to end
until the end of the last subdisk.
The subdisks in a concatenated plex do not have to be physically
contiguous and can belong to more than one VM disk. Concatenation
using subdisks that reside on more than one VM disk is called
spanning.
Figure 1-8, Example of Concatenation, shows concatenation with one
subdisk.