Users guide

9 Intel® RAID Software User Guide
2 RAID Levels
The RAID controller supports RAID levels 0, 1E, 5, 6, 10, 50, and 60. The supported
RAID levels are summarized below. In addition, it supports independent drives
(configured as RAID 0). This chapter describes the RAID levels in detail.
2.1 Summary of RAID Levels
• RAID 0: Uses striping to provide high data throughput, especially for large files in
an environment that does not require fault tolerance. In Intel
®
IT/IR RAID, RAID 0
is also called Integrated Striping (IS), which supports striped arrays with two to ten
disks.
• RAID 1: Uses mirroring so that data written to one disk drive simultaneously writes
to another disk drive. This is good for small databases or other applications that
require small capacity but complete data redundancy. In Intel
®
IT/IR RAID, RAID
1 is also called Integrated Mirroring (IM) which supports two-disk mirrored arrays
and hot-spare disks.
• RAID 5: Uses disk striping and parity data across all drives (distributed parity) to
provide high data throughput, especially for small random access.
• RAID 6: Uses distributed parity, with two independent parity blocks per stripe, and
disk striping. A RAID 6 virtual disk can survive the loss of two disks without losing
data.
• RAID IME: Integrated Mirroring Enhanced (IME) which supports mirrored arrays
with three to ten disks, plus hot-spare disks. This is implemented in Intel
®
IT/IR
RAID.
• RAID 10: A combination of RAID 0 and RAID 1, consists of striped data across
mirrored spans. It provides high data throughput and complete data redundancy but
uses a larger number of spans.
• RAID 50: A combination of RAID 0 and RAID 5, uses distributed parity and disk
striping and works best with data that requires high reliability, high request rates,
high data transfers, and medium-to-large capacity.
Note: It i
s not recommended to have a RAID 0, RAID 5, and RAID 6 virtual disk in
the same physical array. If a drive in the physical array has to be rebuilt, the
RAID 0 virtual disk will cause a failure during the rebuild.
• RAID 60: A combination of RAID 0 and RAID 6, uses distributed parity, with two
independent parity blocks per stripe in each RAID set, and disk striping. A RAID
60 virtual disk can survive the loss of two disks in each of the RAID 6 sets without
losing data. It works best with data that requires high reliability, high request rates,
high data transfers, and medium-to-large capacity.