Configuration Strategies, Continued
Maximizing Drive Availability You can maximize the availability of data on the physical disk drive in the logical array by maximizing the level of fault tolerance. The levels of fault tolerance provided by the RAID levels are:
RAID Level | Fault Tolerance Protection |
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0 | No fault tolerance. |
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1 | Disk mirroring, which provides 100% data redundancy. |
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3 | 100% protection through a dedicated parity drive. |
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5 | 100% protection through striping and parity. The data is |
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| striped and parity data is written across a number of physical |
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| disk drives. |
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10 | 100% protection through data mirroring. |
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30 | 100% protection through data striping. All data is striped |
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| across all drives in two or more arrays. |
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50 | 100% protection through data striping and parity. All data is |
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| striped and parity data is written across all drives in two or |
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| more arrays. |
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Maximizing Drive Performance You can configure an array for optimal performance. But optimal drive configuration for one type of application will probably not be optimal for any other application. A basic guideline of the performance characteristics for RAID drive arrays at each RAID level is:
| RAID Level | Performance Characteristics |
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0 | Excellent for all types of I/O activity, but provides no data |
| |
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| security. |
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1 | Provides data redundancy and good performance. |
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3 | Provides data redundancy. |
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5 | Provides data redundancy and good performance in most |
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| environments. |
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10 | Provides data redundancy and excellent performance. |
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30 | Provides data redundancy and good performance in most |
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| environments. |
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50 | Provides data redundancy and very good performance. |
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44MegaRAID Express 500 Hardware Guide