Figure 1 - 16 Logical Drive Composed Of 24 Drives; Figure 1 - 17 Logical Volume With 4 Logical Drives - Compaq External RAID Controller & Subsystem Infortrend Operation Manual

Figure 1 - 16 Logical Drive Composed of 24 Drives

RAID 5 Logical Drive
24 drives, 1 redundancy drive
Configuration A - One logical drive with all 24 drives
As illustrated above, Configuration A is a RAID 5 logical drive
consisting of 24 physical drives. Configuration B is a logical volume
made of four RAID 5 logical drives.

Figure 1 - 17 Logical Volume with 4 Logical Drives

Configuration B can help to reduce the chance of encountering
points of failure:
a) Higher Redundancy: Configuration A has one dedicated spare,
while Configuration B allows the configuration of four spares. In
Configuration B, the risk of simultaneous drive failure in a logical
drive is significantly reduced than in Configuration A. The total
array capacity is comparatively smaller by the use of spares.
b) Less Rebuild Time: The time during rebuild is a time of hazard.
For example, a RAID 5 logical drive can only withstand single drive
failure, if another drive fails during the rebuild process, data will be
lost. The time span for rebuilding a faulty drive should be
Infortrend
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