Sans Digital ELITERAID ER316FD+B, Руководство пользователя

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Dual-level RAID
achieves a balance between the increased data availability
inherent in RAID 1 and RAID 5 and the increased read performance inherent in
disk striping (RAID 0). These arrays are sometimes referred to as
RAID 0+1
or
RAID 10 and RAID 0+5 or RAID 50.
In summary:
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RAID 0 is the fastest and most efficient array type but offers no fault-
tolerance. RAID 0 requires a minimum of two drives.
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RAID 1 is the best choice for performance-critical, fault-
tolerant environments. RAID 1 is the only choice for fault-tolerance if no
more than two drives are used.
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RAID 3 can be used to speed up data transfer and provide fault-tolerance
in single-user environments that access long sequential records. However,
RAID 3 does not allow overlapping of multiple I/O operations and requires
synchronized-spindle drives to avoid performance degradation with short
records. RAID 5 with a small stripe size offers similar performance.
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RAID 5 combines efficient, fault-tolerant data storage with
good performance characteristics. However, write performance and
performance during drive failure is slower than with RAID 1. Rebuild
operations also require more time than with RAID 1 because parity
information is also reconstructed. At least three drives are required for
RAID 5 arrays.
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RAID 6 is essentially an extension of RAID level 5 which
allows for additional fault tolerance by using a second independent
distributed parity scheme (two-dimensional parity). Data is striped
on a block level across a set of drives, just like in RAID 5, and a
second set of parity is calculated and written across all the drives; RAID
6 provides for an extremely high data fault tolerance and can sustain
multiple simultaneous drive failures. Perfect solution for mission critical
applications.