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C. RAID Concept
Appendix C: RAID Concept
RAID stands for Redundant Array of Inexpensive Drive. Some of the advantages of
using a RAID storage subsystem are:
* Provides disk spanning by weaving all connected drives into one single volume.
* Increases disk access speed by breaking data into several blocks for reading/
writing it to several drives in parallel. With RAID, storage speed increases as
more drives are added. Without RAID, the speed slows down as more drives are
installed.
* Provides fault-tolerance by mirroring or parity operation.
RAID 0
Block Striping - Data is broken into logical blocks, the size of a SCSI disk block,
and striped across several drives.
Drive 0
Drive 1
A0
A1
B0
B1
C0
C1
D0
D1
RAID 1
Mirroring and Striping - Copy of the same data is recorded into two set of striping
drives. In the event of failure, the duplicate set continues operation.
Set 1
Drive 0
A0
A2
A4
B1
ASUS PCI-DA2100 User's Manual
Drive 2
A2
B2
C2
D2
Drive 1
Drive 0
A1
A0
A3
A2
B0
A4
B2
B1
Drive 3
Drive 4
A3
A4
B3
B4
C3
C4
D3
D4
Set 2
Drive 1
A1
A3
B0
B2
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