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RAID Level-1
RAID level-1 provides 100% data redundancy and requires two hard
disk drives. With RAID level-1, the first half of a stripe is the original
data; the second half of a stripe is a
mirror (copy) of the data, but
written to another drive.
Because the data is mirrored, the capacity of the logical drive when
assigned RAID level-1 is 50% of the physical capacity of the two
hard disk drives in the array.
The following illustration shows data arranged in an array of two hard
disk drives defined as one RAID level-1 logical drive. Notice that the
data on Drive B is a mirror copy of the data on Drive A.
If one of the hard disk drives fails, the ServeRAID controller switches
read and write requests to the remaining functional drive in the array.
Drive A
.
.
Drive B
.
.
Data Stripe 1
Block 1
Mirror Stripe 1
Block 1
Data Stripe 2
Block 2
Mirror Stripe 2
Block 2
Data Stripe 3
Block 3
Mirror Stripe 3
Block 3
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IBM ServeRAID-3H and ServeRAID-3L Adapters
Содержание Netfinity ServeRAID-3H
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