User's Manual

4 Contents
Common Storage Tasks . . . . . . . . . . . . . . . . . 31
3 Understanding RAID Concepts . . . . . . . 33
What Is RAID? . . . . . . . . . . . . . . . . . . . . . . 33
Hardware and Software RAID
. . . . . . . . . . . 34
RAID Concepts
. . . . . . . . . . . . . . . . . . . 34
RAID Levels . . . . . . . . . . . . . . . . . . . . . 35
Organizing Data Storage for Availability and
Performance
. . . . . . . . . . . . . . . . . . . . . . . 35
Choosing RAID Levels and Concatenation . . . . . . . 37
Concatenation
. . . . . . . . . . . . . . . . . . . 37
RAID Level 0 (Striping) . . . . . . . . . . . . . . . 39
RAID Level 1 (Mirroring)
. . . . . . . . . . . . . . 40
RAID Level 5 (Striping with distributed parity)
. . . 42
RAID Level 6 (Striping with additional
distributed parity) . . . . . . . . . . . . . . . . . . 43
RAID Level 50 (Striping over RAID 5 sets) . . . . . 45
RAID Level 60 (Striping over RAID 6 sets)
. . . . . 47
RAID Level 10 (Striping over mirror sets)
. . . . . . 49
RAID Level 1-Concatenated (Concatenated
mirror) . . . . . . . . . . . . . . . . . . . . . . . . 51
Considerations for RAID 10 and 50 on
PERC 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, and 4e/Di
. . . 52
Comparing RAID Level and Concatenation
Performance
. . . . . . . . . . . . . . . . . . . . . . . 53
No-RAID
. . . . . . . . . . . . . . . . . . . . . . . . . 55