Raid Configurations - NEC S1300 User Manual

RAID Configurations

* A combination of disk modules of the same capacity and same rotational speed are required for
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Available DAU RAID configurations are shown in Table 1-4.
Table 1-4. RAID Configurations
RAID Level
Number of physical drives in configuration 1, 3, 5, 10,
Number of logical drives per subsystem
Storage capacity per With 36-GB disks
logical drive
With 73-GB disks
With 146 GB disks
configuring logical drives.
Characteristics of the RAID levels are shown in Table 1-5.
Table 1-5. RAID Level Characteristics
Level Function
RAID0 Striping
RAID1 Mirroring
All data is written to two
disk modules.
RAID5 Striping of data and
redundant data
RAID10 Use of both mirroring
and striping
RAID0 RAID1
1+1
15
1,024 max.
35.7 to 35.7GB
536.1GB
71.6 to 71.6GB
1074GB
142.9 to 142.9GB
2144GB
Advantage
Highest data read/write rate
Maximum storage capacity
Data recovery enabled
Minimum data recovery time
Data recovery enabled
Larger capacity is available for
users because the capacity of
redundant data is smaller than
that of RAID1.
High-speed data write
Data recovery enabled
High-speed data read/write
RAID5 RAID10
2+1 to 14+1 2+2 to 7+7
71.4 to 71.4 to
500.3GB 250.1GB
143.2 to 143.2 to
1002GB 501.2GB
285.8 to 285.8 to
2001GB 1000GB
Disadvantage
Data recovery disabled
(Fault in a single disk
module causes data to be
lost.)
Low-speed data writing
The required disk capacity
is twice the used storage
capacity.
Three or more disk
modules are required.
The required storage
capacity is one extra
physical disk per rank.
Four or more disk modules
are required.
The required storage
capacity of disk module is
twice the used storage
capacity.
Disk Array Unit Overview 1-13