NEC Express5800 User Manual page 98

4-38 Configuring Your Server
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 defected, the other HDD containing the same data can substitute for the defected HDD.
Thus the system can continue to operate without interruption.
RAID10
Data to be recorded is distributed to two HDDs in mirroring mode. Then, each mirrored data is
written onto HDD by striping. Owing to this feature, high disk access performance of RAID0 and,
in addition, high reliability of RAID1 can be achieved.
HDD 1
Stripe 1
Stripe 3
Stripe 5
RAID Controller
HDD 1
Stripe 1
Stripe 2
RAID Controller
HDD 2
Stripe 1
Stripe 3
Stripe 5
RAID1
HDD 2
Stripe 1
Stripe 2
HDD 3
Stripe 2
Stripe 4
Stripe 6
RAID1
RAID0
HDD 4
Stripe 2
Stripe 4
Stripe 6