Raid 3; Raid 5; Figure 1 - 7 Raid 3; Figure 1 - 8 Raid 5 - Compaq External RAID Controller & Subsystem Infortrend Operation Manual

"RAID (0+1)" will not appear in the list of RAID levels supported by the
controller. If you wish to perform RAID 1, the controller will determine
whether to perform RAID 1 or RAID (0+1). This will depend on the
number of drives that has been selected for the logical drive.

RAID 3

Disk Striping with Dedicated Parity Disk

Figure 1 - 7 RAID 3

Logical Drive
Block 1
Block 2
Block 1
Block 3
Block 3
Block 4
Block 5
Block 5
Block 7
Block 6
.
Block 7
.
Block 8
.
.

RAID 5

Striping with Interspersed Parity

Figure 1 - 8 RAID 5

Logical Drive
Block 1
Striping + non-dedicated Parity
Block 2
Block 1
Block 3
Parity (3,4)
Block 4
Block 6
Block 5
Block 7
Block 6
Block 7
Block 8
.
.
RAID 30 an RAID 50
please refer to the proceeding discussions for more details.
Functional Description
IMPORTANT!
P h y s i c a l D i s k s
Dedicated
Parity
S t r i p i n g
Block 2 Parity (1,2)
Block 4 Parity (3,4)
Block 6 Parity (5,6)
Block 8 Parity (7,8)
. .
. .
Physical Disks
Block 2 Parity (1,2)
Block 3 Block 4
Parity (5,6) Block 5
Block 8 Parity (7,8)
. . .
. . .
RAID 3
Minimum
Disks required
Capacity
Redundancy
RAID 3 performs Block Striping with
Dedicated Parity. One drive member is
dedicated to storing the parity data. When
a drive member fails, the controller can
recover/regenerate the lost data of the
failed drive from the dedicated parity
drive.
RAID 5
Minimum
Disks required
Capacity
Redundancy
RAID 5 is similar to RAID 3 but the
parity data is not stored in one
dedicated hard
information is interspersed across the
drive array. In the event of a failure, the
controller can recover/regenerate the
lost data of the failed drive from the
other surviving drives.
are implemented as logical volumes,
3
N-1
Yes
3
N-1
Yes
drive. Parity
1-5