42 Planning: MD3200i Series Storage Array Terms and Concepts
RAID 1 is recommended for small databases or other applications that do not
require large capacity for example accounting, payroll, or financial
applications. RAID 1 provides full data redundancy.
RAID 5
RAID 5 uses parity and striping data across all physical disks (distributed
parity) to provide high data throughput and data redundancy, especially for
small random access. RAID 5 is a versatile RAID level and is suited for multi-
user environments where typical I/O size is small and there is a high
proportion of read activity such as file, application, database, web, e-mail,
news, and intranet servers.
RAID 6
RAID 6 is similar to RAID 5 but provides an additional parity disk for better
redundancy. RAID 6 is the most versatile RAID level and is suited for multi-
user environments where typical I/O size is small and there is a high
proportion of read activity. RAID 6 is recommended when large size physical
disks are used or large number of physical disks are used in a disk group.
RAID 10
RAID 10, a combination of RAID 1 and RAID 0, uses disk striping across
mirrored disks. It provides high data throughput and complete data
redundancy. Utilizing an even number of physical disks (four or more) creates
a RAID level 10 disk group and/or virtual disk. Because RAID levels 1 and 10
use disk mirroring, half of the capacity of the physical disks is utilized for
mirroring. This leaves the remaining half of the physical disk capacity for
actual storage. RAID 10 is automatically used when a RAID level of 1 is
chosen with four or more physical disks. RAID 10 works well for medium-
sized databases or any environment that requires high performance and fault
tolerance and moderate-to-medium capacity.
Segment Size
Disk striping enables data to be written across multiple physical disks. Disk
striping enhances performance because striped disks are accessed
simultaneously.
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