Intel
®
RAID Software User’s Guide 11
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. Table 2 provides an overview of RAID 1.
Table 2. RAID 1 Overview
Figure 2. RAID 1 - Disk Mirroring/Disk Duplexing
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 provides an overview of RAID 5.
Uses
Use RAID 1 for small databases or any other environment that requires fault
tolerance but small capacity.
Strong Points
Provides complete data redundancy. RAID 1 is ideal for any application that
requires fault tolerance and minimal capacity.
Weak Points
Requires twice as many disk drives. Performance is impaired during drive
rebuilds.
Drives
2 to 32 (must be an even number of drives)
RAID Adapter
ABC
A
B
C
A
B
C
Disk Mirroring
RAID 1
Available Capacity
N=# disks
C = Disk Capacity
Available Capacity =
(N*C) /2
RAID 1
To Next Page
Loading...
Need help?
General
