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2. RAID Levels
This section details the RAID levels which the disk array controller can support.
2-1. Characteristics of RAID Levels
The table below lists the characteristics of the RAID levels.
Level
Function
RAID0
Striping
RAID1
Mirroring
RAID5
Striping of both data
and redundant data
2-2. RAID0
In RAID 0, data to be recorded is distributed to HDDs. The mode is called "striping".
In the figure below, data is recorded in stripe 1 (disk 1), stripe 2 (disk 2), and stripe 3 (disk
3)... in the order. Because RAID0 allows all HDDs to be accessed collectively, it can
provide the best disk access performance.
Notice
Redundancy
No
Yes
Yes
RAID 0 cannot have data redundancy. If a HDD is defected, the data saved
in the HDD cannot be recovered.
Disk array controller
Disk 1
Stripe 1
Stripe 4
Characteristics
Data read/write at the highest rate
Largest capacity
Capacity: (capacity of single HDD) ×
(number of HDDs)
Two HDDs required
Capacity: capacity of single HDD
Three or more HDDs required
Capacity: (capacity of single HDD) ×
((number of HDDs) - 1)
Disk 2
Stripe 2
Stripe 5
Disk 3
Stripe 3
Stripe 6
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