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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
RAID10
Combination of striping
and mirroring
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 (disk1), 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
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)
Four HDDs required
Capacity: (capacity of single HDD) × 2
Disk 2
Disk 3
Stripe 2
Stripe 3
Stripe 5
Stripe 6