PLANET NAS-7400 User Manual
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7.1.3 RAID 5 – Block Striping with Distributed Parity Mirror
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
Distributed Parity
disk drives
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.
7.1.4 RAID 10 – Mirror / Stripe
Mirror/Stripe combines both of the RAID 0 and RAID 1 types. RAID 10 can
increase performance by reading and writing data in parallel while
protecting data with duplication. At least four disk drives are needed for
RAID 10 to be installed. With a four-disk-drive RAID Volume, one drive pair
is mirrored together then striped over a second drive pair.