VERITAS Volume Manager 3.1 Storage Administrator Administrator's Guide

Volume Tasks
Creating a Volume
Chapter 4152
Mirrored • Mirroring provides protection
against disk failure and
reduces the risk of data loss.
• Mirroring provides data
redundancy by maintaining
multiple complete copies of a
volume’s data on different
disks.
• Mirroring provides improved
read performance.
• A mirrored volume requires extra
disk space. Each mirror requires
enough disk space to contain a
complete copy of the volume.
Concatenated Pro • The volume is layered and
mirrored. This provides
improveddataredundancy and
reduces the impact of disk
failures.
• Recovery time is quicker than
with regular concatenated
volumes that are mirrored.
• The volume can consist of disk
regions that are not adjacent.
• The volume can span multiple
disks. A spanned volume can
have a greater capacity than a
single disk.
• A concatenated pro volume
requires at least two disks.
• Concatenation does not improve
I/O performance.
• Layered volumes consist of more
Volume Manager objects than
non-layered volumes and are
likely to fill up the disk group’s
configuration database sooner.
When the configuration database
is full, you cannot create more
volumes in the disk group.
Table 4-1 Layout Comparison
Layout Advantages Disadvantages