Selecting a RAID Level
Level | Description and | Pros | Cons | Max. | Fault | ||
| Use |
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| Drives | Tolerant | ||
0 | Data divided in | High data | No fault | One to | No | ||
| blocks and | throughput | tolerance. All | 32 |
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| distributed | for large | data lost if |
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| sequentially (pure | files | any drive |
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| striping). Use for |
| fails. |
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| that requires high |
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| performance. |
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1 | Data duplicated on | 100% data | Doubles disk | 2, 4, 6, | Yes | ||
| another disk | redundancy | space. | or 8 |
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| (mirroring). Use |
| Reduced |
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| for |
| performance |
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| during |
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| systems |
| rebuilds. |
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3 | Disk striping with a | Achieves | Performance | Three to | Yes | ||
| dedicated parity | data | not as good as | eight |
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| drive. Use for non- | redundancy | RAID 1 |
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| interactive apps | at low cost |
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| that process large |
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| files sequentially. |
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5 | Disk striping and | Achieves | Performance | Three to | Yes | ||
| parity data across | data | not as good as | eight |
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| all drives. Use for | redundancy | RAID 1 |
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| high read volume | at low cost |
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| but low write |
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| volume, such as |
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| transaction |
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| processing. |
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10 | Data striping and | High data | More | 4, 6, or | Yes | ||
| mirrored drives. | transfers, | complicated | 8 |
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| complete |
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| redundancy |
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30 | Disk striping with a | High data | More | Six to | Yes | ||
| dedicated parity | transfers, | complicated | 32 |
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| drive. | redundancy |
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50 | Disk striping and | High data | More | Six to | Yes | ||
| parity data across | transfers, | complicated | 32 |
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| all drives. | redundancy |
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20ADAC Ultra2 S466 Hardware Guide