Compaq Infortrend Manuale Utente

Functional Description

1-5

Block 1

Block 2

Block 3

Block 4

Block 5

Block 6

Block 7

Block 8

.
.

Logical Drive

P h y s i c a l D i s k s

Block 1

Block 3

Block 5

Block 7

Block 2

Block 4

Block 6

Block 8

S t r i p i n g

Parity (1,2)

Parity (3,4)

Parity (5,6)

Parity (7,8)

Dedicated

Parity

.
.

Block 1

Block 2

Block 3

Block 4

Block 5

Block 6

Block 7

Block 8

.
.

Logical Drive

Physical Disks

Block 1

Parity (3,4)

Block 6

Block 7

Block 2

Block 3

Parity (5,6)

Block 8

Parity (1,2)

Block 4

Block 5

Parity (7,8)

.
.

Striping + non-dedicated Parity

IMPORTANT!

•

“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

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

Striping with Interspersed Parity

Figure 1 - 8 RAID 5

RAID 5 is similar to RAID 3 but the
parity data is not stored in one
dedicated hard drive. Parity
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.

RAID 30 an RAID 50

are implemented as logical volumes,

please refer to the proceeding discussions for more details.

RAID 5

Minimum
Disks required

Capacity

N-1

Redundancy

Yes

RAID 3

Minimum
Disks required

Capacity

N-1

Redundancy

Yes