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About RAID
Spanned Volume
A spanned volume is created by joining, or concatenating, two or
more drives. T he drives do not have to b e of equal ca pacity and a re
connected end-to-end. A spanned volume offers no redundancy
and no performance advantage over a single drive.
RAID 0
A RAID0 is created by striping data across two or more drives.
This striping scheme creates no redundancy to protect the data.
However, because the drives share load equally, RAID0 provides
the best read and write performance of any RAID type.
An example of a RAID0 array is shown below.
RAID 1
A RAID1 array is created by copying, or mirroring, all data from
one drive onto a second drive. This mirroring provides redundancy,
ensuring that if one drive fails no data is lost. Redundancy also
means that only half of the total capacity is available.
RAID 1 offers no write performance advantage over a simple
volume configuration.
However, because the drives share read load
equally, RAID1 provides improved
read performance. An example
of a RAID 1 array is shown above.
RAID 0
Data 0
Data 2
Data 4
Data 6
Data 1
Data 3
Data 5
Data 7
Drive Drive
RAID 1
Data 0
Drive Drive
Data 1
Data 2
Data 3
Data 0
Data 1
Data 2
Data 3