NEC VERSA S1300 Series, Руководство пользователя

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RAID Configuration
The RAID configuration in the disk array unit can be used in the combinations shown in
the table below.
Table 1-1 Possible RAID Combinations
RAID level RAID0 RAID1 RAID5 RAID10
Number of physical drives in configuration 1, 3, 5, 10,
15
1+1 2+1 to 14+1 2+2 to 7+7
Number of logical drives per subsystem 1,024 max.
With additional
36-GB disk drives 35.7 to
536.1GB 35.7GB 71.4 to
500.3GB
71.4 to
250.1GB
With additional
72-GB disk drives 71.6 to
1074GB 71.6GB 143.2 to
1002GB
143.2 to
501.2GB
Storage capacity per
logical drive
With additional
146-GB disk drives 142.9 to
2144GB 142.9GB 285.8 to
2001GB
285.8 to
1000GB
* A combination of disk drives of the same capacity and same rotational speed is required for
configuring (binding) logical drives.
The RAID levels have the following characteristics.
Table 1-2 RAID Levels
Level Function Advantage Disadvantage
RAID0 Striping Highest data read/write rate
Maximum storage capacity
Data recovery disabled
(Fault in a single disk drive
causes data to be lost.)
RAID1 Mirroring Data recovery enabled Low-speed data writing
All data is written to two
disk drives. Minimum data recovery time Higher cost, since twice
the number of drives is
required (50% capacity
utilization)
RAID5 Striping of data and
parity Data recovery enabled Three or more disk drives
are required.
Larger capacity is available for
users because the capacity of
redundant data is smaller than
that of RAID1. The array capacity is N-1,
with a minimum of 3 drives
required.
Adding more disk drives
increases rebuild (or “auto
repair”) time.
High-speed data write
RAID10 Use of both mirroring
and striping
Data recovery enabled Four or more disk drives
are required.
High-speed data read/write Like RAID1, RAID10 still
requires twice the number
of disks.
System Overview 1-15