User`s guide

4-19
RAID Levels
Characteristics of the RAID Levels
The table below lists the characteristics of the RAID levels.
Level Function Redundancy Characteristics
RAID0 Striping No • Data read/write at the highest rate
• Largest capacity
• Capacity: (capacity of single HDD) ×
(number of HDDs)
RAID1 Mirroring Yes • Two HDDs required
• Capacity: capacity of single HDD
RAID5
Striping of both data
and redundant data
Yes
• Three or more HDDs required
• Capacity: (capacity of single HDD) ×
((number of HDDs) - 1)
RAID6
Striping of both data
and redundant data
Yes
• Three or more HDDs required
• Capacity: (capacity of single HDD) ×
((number of HDDs) - 2)
RAID10 Spanning of RAID1 Yes • Four or more HDDs required
• Capacity: (capacity of single HDD) ×
((number of HDDs) - 2)
RAID50 Spanning of RAID5 Yes • Six or more HDDs required
• Capacity: (capacity of single HDD) ×
((number of HDDs) - 2)
IMPORTANT: To use RAID 5 or RAID 6, you need to install the optional RAID Upgrade
Kit.
RAID0
In RAID0, 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 this order. Because
RAID0 allows all the HDDs to be accessed in parallel, it provides the best disk access performance.
IMPORTANT: RAID0 does not have data redundancy. If a HDD is defective, the data
saved in the HDD cannot be recovered.
RAID Controller
HDD 1 HDD 2
Stripe 1
HDD 3
Stripe 4
Stripe 2
Stripe 5
Stripe 3
Stripe 6