Proware SB-1413-UA, Installation And Configuration Manual

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USB and eSATA to SATA II RAID Subsystem
Installation and Configuration Manual
18
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 one drive.
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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.
RAID Management
The subsystem can implement several different levels of RAID technology. RAID levels supported by
the subsystem are shown below.
RAID Level Description
Min. Drives
0
Block striping is provide, which yields higher
performance than with individual drives. There is no
redundancy.
1
1
Drives are paired and mirrored. All data is 100%
duplicated on an equivalent drive. Fully redundant.
2
3
Data is striped across several physical drives. Parity
protection is used for data redundancy.
3
5
Data is striped across several physical drives. Parity
protection is used for data redundancy.
3
1 + 0
Combination of RAID levels 0 and 1. This level provides
redundancy through mirroring and striping.
4