must be available 24 hours per day? Will the information stored in this disk array contain large audio or video files that must be available on demand? Will this disk array contain data from an imaging system? You must identify the purpose of the data to be stored in the disk subsystem before you can confidently choose a RAID level and a RAID configuration.
5.5Planning the Array Configuration
Fill out Table 5.8 to help plan this array.
Table 5.8 | Factors for Planning the Array Configuration | |
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Question |
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Number of MegaRAID SCSI channels |
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Number of physical disk drives in the array |
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Purpose of this array. Rank the following factors: |
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Maximize drive capacity |
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Maximize the safety of the data (fault tolerance) |
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Maximize hard drive performance and throughput |
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Number of hot spares |
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Amount of cache memory installed on MegaRAID SCSI |
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Are all of the disk drives and the server protected by an |
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uninterruptible power supply? |
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5.5.1Using the Array Configuration Planner
Table 5.9 lists the possible RAID levels, fault tolerance, and effective capacity for all possible drive configurations for an array consisting of one to eight drives. This table does not take into account any hot spare (standby) drives. You should always have a hot spare drive in case of drive failure. RAID 1 requires two drives, RAID 10 at least four, and RAID 50 at least six.
Configuring Physical Drives, Arrays, and Logical Drives |
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