Arrays With No Redundancy: Raid Level 0 - HP D5970A - NetServer - LCII Installation And Configuration Manual

Chapter 2

Arrays with No Redundancy: RAID Level 0

RAID 0: Striping
In RAID 0 configurations, data is distributed among hard disks in the array via
an algorithm called striping. Data written to a logical drive is divided into pieces
called blocks. RAID 0 provides no data redundancy. If one hard disk fails, the
data is lost from the entire logical drive and must be retrieved from a backup
copy. If you have five physical drives configured as one RAID 0 logical drive,
data blocks are written as follows:
Disk 1
Stripe 1 Block 1
Stripe 2 Block 6
The RAID 0 algorithm allows data to be accessed on multiple disks
simultaneously. Read and write performance on a multidisk RAID 0 system is
significantly faster than on a single drive system.
RAID 0 Advantages
Provides maximum data capacity, because all disk space is used for data.
Costs are low, because no disk space is allocated for redundancy.
Access time is fast for both reads and writes.
RAID 0 Disadvantages
RAID 0 provides no redundancy so if a hard drive fails, data must be restored
from backup.
Hot spares cannot be used with RAID 0 configurations.
RAID 0 Summary
Choose RAID 0 if redundancy is not required, and you need fast performance and
low costs.
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Disk 2 Disk 3
Block 2 Block 3
Block 7 Block 8
RAID Overview
Disk 4 Disk 5
Block 4 Block 5
Block 9 Block 10