Bull Cedoc NovaScale R440 E2, Руководство пользователя

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Configuring Your Server 4-27
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 the order. Because RAID0
allows all HDDs to be accessed collectively, it can provide the best disk access performance.
IMPORTANT: RAID0 cannot have data redundancy. If a HDD is defected, 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
RAID1
In the RAID1 level, data saved in a HDD is written to another HDD without change. The mode is called "mirroring".
When data is written onto a single HDD, the same data is written onto another HDD. If either of the HDDs is defective, the
other HDD containing the same data can substitute for the defective HDD. Thus the system can continue to operate without
interruption.
RAID Controller
HDD 1 HDD 2
Stripe 1
Stripe 2
Stripe 1
Stripe 2
RAID5
In RAID5, data is distributed to HDDs by striping and, at the same time, the parity (redundant data) is distributed to the HDDs.
This mode is called "striping with distributed parity".
Each of stripe x, stripe x+1, and parity (x, x+1) created from stripe x and stripe x+1 is written onto a specific HDD.
Accordingly, the total capacity assigned to the parity is just the same as the capacity of a single HDD. If any of the HDDs
configuring a logical drive is defective, data is still available without problems.