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

Volume Tasks
VxVM Volumes
Chapter 4108
Striped • Striping provides
improved read and
write performance.
• Striping can help to
balance the I/O load
from multi-user
applications across
multiple disks.
• The volume can be
mirrored to protect
data against disk
failure.
• There is a risk of
data loss if the
volume is not
mirrored.
• Striping a volume
across multiple disks
increases the chance
that a disk failure
will result in the
failure of the volume.
• A striped volume
requires at least two
disks.
RAID-5 • RAID-5 provides
protection against
disk failure and
reduces the risk of
data loss.
• RAID-5 provides
data redundancy by
storing parity (a
calculated value) on
the disks. If a disk
fails, the parity is
used to reconstruct
the missing data.
• RAID-5 requires
less storage space
than mirroring.
• RAID-5 provides
improved read
performance.
• RAID-5 provides
relatively slow write
performance.
• RAID-5 volumes
cannot be mirrored.
• A RAID-5 volume
requires at least
three disks. If logging
is enabled, a RAID-5
volume requires at
least four disks.
• A RAID-5 volume
cannot survive
multiple disk
failures. However,
optional RAID-5 logs
reduce this risk.
• If one of the volume
disks is inaccessible,
performance is
degraded.
Table 4-1 Layout Comparison (Continued)
Layout Advantages Disadvantages