RAID Levels
2-19
2.5.4
RAID 1
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.
Figure 2.6
provides
a graphic example of a RAID 1 drive group.
Figure 2.6
RAID 1 Drive Group
2.5.5
RAID 5
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.
Table 2.6
RAID 1 Overview
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 drives. Performance is impaired
during drive rebuilds.
Drives
2 - 32 (must be an even number of drives)
Segment 1
Segment 1
Duplicate
Segment 2
Segment 3
Duplicate
Segment 4
Duplicate
Segment 3
Segment 4
Segment 5
Segment 6
Segment 7
Segment 8
Segment 5
Duplicate
Segment 6
Duplicate
Segment 7
Duplicate
Segment 8
Duplicate
Segment 2
Duplicate
...
...
...
...
RAID1
RAID1
RAID1
RAID1
Summary of Contents for ThinkServer RD230
Page 1: ...ThinkServer RD230 RD240 and TD230 MegaRAID SAS Software User Guide ...
Page 2: ......
Page 3: ...ThinkServer RD230 RD240 and TD230 MegaRAID SAS Software User Guide ...
Page 16: ...Contents ...
Page 24: ...Contents ...
Page 68: ...2 36 Introduction to RAID ...
Page 252: ...7 10 MegaRAID Storage Manager Window and Menus ...
Page 300: ...8 48 Configuration ...
Page 328: ...9 28 Monitoring System Events and Storage Devices ...
Page 334: ...10 6 Maintaining and Managing Storage Configurations ...
Page 360: ...B 12 Glossary ...
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