User's Guide

Configuring Your Server 4-31
RAID Levels
This section details the RAID levels which the on-board RAID (LSI Logic MegaRAID SAS PCI
EXPRESS ROMB) can support.
Characteristics of 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)
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.
IMPORTANT: RAID 0 cannot have data redundancy. If a HDD is
defected, the data saved in the HDD cannot be recovered.
Disk array controller
HDD 1 HDD 2
Stripe 1
HDD 3
Stripe 4
Stripe 2
Stripe 5
Stripe 3
Stripe 6