VERITAS Volume Manager 3.5 User's Guide - VERITAS Enterprise Administrator (September 2004)

Volume Tasks
VxVM Volumes
Chapter 4 111
NOTE The total volume size you indicate for the volume in the Create Volume
Wizard is the usable size for storing the data. Depending on the layout
type, the volume can take more space on the disk. The size shown in the
Wizard for simple, striped, and spanned volumes is the actual volume
size on the disk. A RAID-5 volume requires additional space for parity
information, and a mirrored volume is a multiple of the space taken by
the original plex of the volume. The Wizard provides a Query Max Size
Striped Pro • The volume is
layered, and stripes
several underlying
mirror volumes.
This provides
improved data
redundancy and
reduces the impact
of disk failures.
This type of volume
is also known as a
striped-mirror
volume.
• Recovery time is
quicker than with
regular striped
volumes that are
mirrored.
• Striping provides
improved read and
write performance.
• Striping can help to
balance the I/O load
from multi-user
applications across
multiple disks.
• A striped pro volume
requires at least four
disks.
• Layered volumes
consist of more
VxVM objects than
non-layered volumes
and are likely to fill
up the disk group
configuration
database sooner.
When the
configuration
database is full, you
cannot create more
volumes in the disk
group.
Table 4-1 Layout Comparison (Continued)
Layout Advantages Disadvantages