Compaq External RAID Controller & Subsystem Infortrend - Nraid; Jbod; Figure 1 - 3 Jbod

Functional Description
1-3
+
+
+
2 GB Hard Drive
3 GB Hard Drive
1 GB Hard Drive
2 GB Hard Drive
Logical
Drive
2 + 3 + 1 + 2 = 8 GB
Logical Drive
=
2 GB Hard Drive
3 GB Hard Drive
1 GB Hard Drive
2 GB Hard Drive
2 GB
LogicalDrive
=
=
=
3 GB
1 GB
2 GB
LogicalDrive
LogicalDrive
LogicalDrive
configure a logical volume. There are more combinations than
RAID 10, 30, and 50.
RAID Level Performance Sequential Performance Random
NRAID
Drive Drive
RAID 0
R: Highest
W: Highest
R: High
W: Highest
RAID 1 (0+1)
R: High
W: Medium
R: Medium
W: Low
RAID 3
R: High
W: Medium
R: Medium
W: Low
RAID 5
R: High
W: Medium
R: High
W: Low
NRAID
Disk Spanning
Figure 1 - 2 NRAID
NRAID stands for Non-RAID. The capacity of all
the drives is combined to become one logical
drive (no block striping). In other words, the
capacity of the logical drive is the total capacity of
the physical drives. NRAID does not provide
data redundancy.
JBOD
Single Drive Control
Figure 1 - 3 JBOD
JBOD stands for Just a Bunch of Drives. The
controller treats each drive as a stand-alone
disk, therefore each drive is an independent
logical drive. JBOD does not provide data
redundancy.
NRAID
Minimum
Disks required
1
Capacity N
Redundancy No
JBOD
Minimum
Disks required
1
Capacity 1
Redundancy No