Raid 5 - Block Striping With Distributed Parity - Promise Technology Smartstor NS4600 Product Manual

SmartStor NS4600 Product Manual
RAID 5 – Block Striping with Distributed Parity
RAID 5 organizes block data and parity data across the disk drives. Generally,
RAID level 5 tends to exhibit lower random write performance due to the heavy
workload of parity recalculation for each I/O. RAID 5 works well for file, database,
application and web servers.
Data
Blocks
Figure 3. RAID 5 Stripes all drives with data and parity information
The capacity of a RAID 5 Volume equals the smallest disk drive times the number
of disk drives, minus one. Hence, a RAID 5 Volume with four 100 GB disk drives
will have a capacity of 300 GB. A RAID Volume with two 120 GB disk drives and
one 100 GB disk drive will have a capacity of 200 GB.
RAID 5 is generally considered to be the most versatile RAID level.
RAID 5 requires a minimum of three disk drives.
Distributed Parity
disk drives
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