Raid 1 - Disk Mirroring/Disk Duplexing; Raid 5 - Data Striping With Striped Parity; Figure 2. Raid 1 - Disk Mirroring/Disk Duplexing; Table 2. Raid 1 Overview - Intel SC5650BCDP Software User's Manual

RAID 1 - Disk Mirroring/Disk Duplexing

In RAID 1, the RAID controller duplicates all data from one drive to a second drive. RAID 1
provides complete data redundancy, but at the cost of doubling the required data storage
capacity.

RAID 5 - Data Striping with Striped Parity

RAID 5 includes disk striping at the block level and parity. Parity is the data's property of
being odd or even, and parity checking detects errors in the data. In RAID 5, the parity
information is written to all drives. RAID 5 is best suited for networks that perform a lot of
small I/O transactions simultaneously.
RAID 5 addresses the bottleneck issue for random I/O operations. Because each drive contains
both data and parity, numerous writes can take place concurrently.
Table 3
®
Intel RAID Software User's Guide
Table 2 provides an overview of RAID 1.
Use RAID 1 for small databases or any other environment that requires fault
Uses
tolerance but small capacity.
Provides complete data redundancy. RAID 1 is ideal for any application that
Strong Points
requires fault tolerance and minimal capacity.
Requires twice as many disk drives. Performance is impaired during drive
Weak Points
rebuilds.
2 to 32 (must be an even number of drives)
Drives
RAID Adapter

Figure 2. RAID 1 - Disk Mirroring/Disk Duplexing

provides an overview of RAID 5.

Table 2. RAID 1 Overview

RAID 1
ABC
Available Capacity
N=# disks
C = Disk Capacity
Available Capacity =
(N*C) /2
A A
B B
C C
Disk Mirroring
RAID 1
11