Sans Digital TOWERRAID TR5M1, Подробное руководство пользователя

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Parity RAID uses less capacity for protection compare to RAID 1 and RAID 10 and is the preferred method to reduce the
cost per Gigabyte for larger installations. Mirroring requires half of the capacity to protect the data whereas the above
example using three hard drives only requires a one-third of the capacity. The additional required capacity decreases as the
number of disks in the group increases (i.e., one-forth for four drives or one-fifth for five drives).
In exchange for protection, Parity RAID degrades performance for write operations. The write performance is slower
compare to RAID 0 is due to each write performed need to calculate the parity. However read performance will be
increase using Stripping Method.
2.3.5 Concatenation (Spanning)
The Concatenated mode combines multiple disks or segments of disks into a single large volume. It does not provide any
data protection or performance improvement but can be useful for utilizing leftover space on disks. Concatenation allows
the segments that make up the volume to be of different sizes.
2.3.6 Contiguous (JBOD/Single Drive/Segment)
The single drive is a virtual disk that can either be an entire disk drive or a segment of a single disk drive. Single drive is the
“Contiguous” configuration option when creating RAID Groups (or sets) in the SATARAID5 software.