Promise Technology 2-Year Extended Warranty for VessR2000 RAID Head - Manual (Page 591)

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Vess R2000 Series Product Manual Promise Technologies
The data capacity RAID 50 logical drive equals the capacity of the smallest physical drive times the number of
physical drives, minus two.
RAID 50 also provides very high reliability because data is still available even if multiple physical drives fail (one
in each axle). The greater the number of axles, the greater the number of physical drives that can fail without
the RAID 50 logical drive going offline.
Components Minimum Maximum
Number of Axles 2 16
Physical Drives per Axle 3 32
Physical Drives per Logical Drive 6 256
RAID 50 Axles
When you create a RAID 50, you must specify the number of axles. An axle re-fers 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 32 physical
drives, de-pending on the number of physical drives in the logical drive.
The chart below shows RAID 50 logical drives with 6 to 32 physical drives, the available number of axles, and
the resulting distribution of physical drives on each axle.
Recommended Applications for RAID 50:
• File and Application servers
• Transaction processing
• Office application with many users accessing small files