Raid 5; Raid 1 Drive Group; Raid 1 Overview - Lenovo ThinkServer RD240 Software User's Manual

2.5.4 RAID 1
Segment 1
Segment 1
Duplicate
Segment 5
Segment 5
Duplicate
...
RAID1
2.5.5

RAID 5

In RAID 1, the RAID controller duplicates all data from one drive to a
second drive in the drive group. RAID 1 supports an even number of
drives from 2 to 32 in a single span. RAID 1 provides complete data
redundancy, but at the cost of doubling the required data storage
capacity. Table 2.6 provides an overview of RAID 1.
a graphic example of a RAID 1 drive group.
Table 2.6

RAID 1 Overview

Uses
Strong Points
Weak Points
Drives
Figure 2.6

RAID 1 Drive Group

Segment 2
Segment 2
Duplicate
Segment 6
Segment 6
Duplicate
...
RAID1
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 is used to
detect 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
input/output (I/O) transactions simultaneously.
RAID Levels
Use RAID 1 for small databases or any other
environment that requires fault tolerance but small
capacity.
Provides complete data redundancy. RAID 1 is ideal for
any application that requires fault tolerance and minimal
capacity.
Requires twice as many drives. Performance is impaired
during drive rebuilds.
2 - 32 (must be an even number of drives)
Segment 3
Segment 3
Duplicate
Segment 7
Segment 7
Duplicate
...
RAID1
Figure 2.6 provides
Segment 4
Segment 4
Duplicate
Segment 8
Segment 8
Duplicate
...
RAID1
2-19