IBM ATA 133, User Manual

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IBM ATA 133 RAID Controller User's Guide 12
RAID 1
RAID 1 duplicates all data from one drive to a second drive. RAID 1 provides complete
data redundancy, but at the cost of doubling the required data storage capacity.
Uses Use RAID 1 for small databases or any other environment that requires fault tolerance but small
capacity.
Strong Points
RAID 1 provides complete data redundancy. RAID 1 is ideal for any application that requires
fault tolerance and minimal capacity.
Weak Points RAID 1 requires twice as many hard drives. Performance is impaired during drive rebuilds.
Drives Two
Figure 3-2. RAID 1 Array
Segment 1
Segment 2
Segment 3
Segment 4 Segment 1 Duplicate
Segment 2 Duplicate
Segment 3 Duplicate
Segment 4 Duplicate
Data Flow