Promise Technology VessRAID 1740s Product Manual page 239

RAID 50 Axles
When you create a RAID 50, you must specify the number of axles. An axle
refers to a single RAID 5 logical drive that is striped with other RAID 5 logical
drives to make RAID 50. An axle can have from 3 to 16 physical drives,
depending on the number of physical drives in the logical drive.
The chart below shows RAID 50 logical drives with 6 to 16 physical drives, the
available number of axles, and the resulting distribution of physical drives on
each axle.
No. of Drives
RAID 50 Logical Drive
No. of Axles
6
7
8
9
10
11
12
13
14
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Chapter 8: Technology Background
Drives per Axle
2
2
2
2
3 3,3,3
2
3 3,3,4
2
3 3,4,4
2
3 4,4,4
4 3,3,3,3
2
3 4,4,5
4 3,3,3,4
2
3 4,5,5
4 3,3,4,4
3,3
3,4
4,4
4,5
5,5
5,6
6,6
6,7
7,7