Disk Spanning; Figure 2-3. Example Of Disk Spanning - Dell PowerEdge Expandable RAID Controller 3 User Manual

Disk Spanning

Disk spanning allows multiple physical drives to function like one big drive.
Spanning overcomes lack of disk space and simplifies storage management
by combining existing resources or adding relatively inexpensive resources.
For example, four 20 GB drives can be combined to appear to the operating
system as a single 80 GB drive.
Spanning alone does not provide reliability or performance enhancements.
Spanned logical drives must have the same stripe size and must be
contiguous. In the following graphic, RAID 1 array is turned into a RAID 10
array.
F i g u r e 2 - 3 . E x a m p l e o f D i s k S p a n n i n g
60 GByte 60 GByte 60 GByte 60 GByte
Can Be Accessed as Can Be Accessed as
One 120 GByte Drive One 120 GByte Drive
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I n tr o d uc t io n t o RA I D