LaCie FIREWIRE 800/400 User Manual

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LaCie Biggest Quadra
User Manual
page 
Understanding RAID
3.2. RAID 0 + 1
High Data Transfer Performance
This  level  combines  striping  and  mirroring,  which 
provides full data redundancy and protects data in the 
event that multiple drives fail (provided that the data on 
one of each mirrored pair of drives is intact). 
Storage capacity in this configuration is determined 
by multiplying the capacity of the smallest disk by two. 
If,  for  instance,  there  were  four  drives  installed  that 
ranged in capacity from 40GB to 70GB, as a RAID 0+1 
array, the total available capacity would be 80GB (40GB 
x 2). In this configuration, you must have an even num-
ber of disks, so in the case of the LaCie Biggest Quadra, 
you would need to have four hard disks installed.
Characteristics and Advantages
Implemented as a mirrored array with RAID 0 
arrays as the segments
The same fault tolerance as RAID level 5
Fault-tolerance overhead is the same as that of 
mirroring
High I/O rates are achieved thanks to multiple 
striped segments
Excellent design for those seeking high perfor-
mance, without achieving maximum reliability
This diagram represents a
RAID 0 +1 array, consisting of
four disks, which are
connected to the Controller.
The Controller creates two
matching RAID 0 arrays on
the four disks.
E
D
C
B
A
CONTROLLER
A
C
E
G
B
D
F
H
R0
R0
A
C
E
G
B
D
F
H
R1
Recommended Uses
Imaging Applications
General Fileserver
Fig. 3.2.