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RAID Level: |
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RAID 4: Independent Data disks with shared Parity disk 
Each entire block is written onto a data disk. Parity for same rank blocks is generated on Writes, recorded on the parity disk and checked on Reads.
RAID Level 4 requires a minimum of 3 drives to implement |
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Characteristics/Advantages
Very high Read data transaction rate
Low ratio of ECC (Parity) disks to data disks means high efficiency
High aggregate Read transfer rate |
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Disadvantages
Quite complex controller design
Worst Write transaction rate and Write aggregate transfer rate
Difficult and inefficient data rebuild in the event of disk failure
Block Read transfer rate equal to that of a single disk |
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