NEC Express5800 User Manual page 111

RAID0
In RAID0, data to be recorded is distributed to hard disk drives. 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 hard disk drives to be accessed collectively, it can provide the
best disk access performance.
IMPORTANT:
drive is defected, the data saved in the hard disk drive cannot be
recovered.
RAID1
In the RAID1 level, data saved in a hard disk drive is written to another hard disk drive without
change. The mode is called "mirroring".
When data is written onto a single hard disk drive, the same data is written onto another hard disk
drive. If either of the hard disk drives is defected, the other hard disk drive containing the same data
can substitute for the defected hard disk drive. Thus the system can continue to operate without
interruption.
RAID0 cannot have data redundancy. If a hard disk
RAID Controller
HDD 1
Stripe 1
Stripe 4
RAID Controller
HDD 1
Stripe 1
Stripe 2
Configuring Your Server 4-41
HDD 2
Stripe 2
Stripe 5
HDD 3
Stripe 3
Stripe 6
HDD 2
Stripe 1
Stripe 2