NEC Express5800/B120b User Manual page 77

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.
RAID Controller
HDD 1
Stripe 1
Stripe 2
Configuring Your Server 4-27
HDD 2
Stripe 1
Stripe 2