Promise Technology 2-Year Extended Warranty for VessR2000 RAID Head - Manual (Page 585)

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Vess R2000 Series Product Manual Promise Technologies
RAID 5 – B
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ARIty
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RAID 5 organizes block data and parity data across the physical drives. Gener-ally, RAID Level 5 tends to
exhibit lower random write performance due to the heavy workload of parity recalculation for each I/O. RAID 5
is generally consi-dered to be the most versatile RAID level. It works well for file, database, appli-cation and web
servers.
The capacity of a RAID 5 logical drive equals the smallest physical drive times the number of physical drives,
minus one. Hence, a RAID 5 logical drive with four 100 GB physical drives has a capacity of 300 GB. A RAID 5
logical drive with two 120 GB physical drives and one 100 GB physical drive has a capacity of 200 GB.
RAID 5 is generally considered to be the most versatile RAID level.
A RAID 5 on Vess consists of 3 to 32 physical drives.
Recommended Applications for RAID 5:
RAID 5 stripes all drives with data and parity information
Physical Drives
Data Blocks
Distributed Parity