VERITAS Volume Manager 3.1 Administrator's Guide

Introduction to Volume Manager

Virtual Object Data Organization (Volume Layouts)

Chapter 140

this example, subdisks disk02-02 and disk02-03 are available for other

disk management tasks.

Figure 1-10, Example of Spanning, shows data spread over two subdisks

in a spanned plex.

Figure 1-10 Example of Spanning

CAUTION Spanning a plex across multiple disks increases the chance that a disk

failure results in failure of the assigned volume. Use mirroring or

RAID-5 (both described later) to reduce the risk that a single disk failure

results in a volume failure.

Striping (RAID-0)

Striping

(RAID-0) maps data so that the data is interleaved among two

or more physical disks. A striped plex contains two or more subdisks,

spread out over two or more physical disks. Data is allocated alternately

and evenly to the subdisks of a striped plex.

The subdisks are grouped into “columns,” with each physical disk limited

disk02-01

B = Block of Data

VM Disks

Physical disks

disk01-01

disk02-02

disk02-03

Data in

disk01-01

Data in

disk02-0

Plex

disk01

disk01-01

devname

disk02

disk02-01

disk02-02

disk02-03