User's Manual

4 Contents
Common Storage Tasks . . . . . . . . . . . . . . . . . 33
3 Understanding RAID Concepts . . . . . . . 35
What Is RAID? . . . . . . . . . . . . . . . . . . . . . . 35
Hardware and Software RAID
. . . . . . . . . . . 35
RAID Concepts
. . . . . . . . . . . . . . . . . . . 36
RAID Levels . . . . . . . . . . . . . . . . . . . . . 37
Organizing Data Storage for Availability and
Performance
. . . . . . . . . . . . . . . . . . . . . . . 37
Choosing RAID Levels and Concatenation . . . . . . . 38
Concatenation
. . . . . . . . . . . . . . . . . . . 39
RAID Level 0 (Striping) . . . . . . . . . . . . . . . 40
RAID Level 1 (Mirroring)
. . . . . . . . . . . . . . 42
RAID Level 5 (Striping with distributed parity)
. . . 43
RAID Level 6 (Striping with additional distributed
parity) . . . . . . . . . . . . . . . . . . . . . . . . 44
RAID Level 50 (Striping over RAID 5 sets) . . . . . 46
RAID Level 60 (Striping over RAID 6 sets)
. . . . . 48
RAID Level 10 (Striping over mirror sets)
. . . . . . 50
RAID Level 1-Concatenated (Concatenated
mirror) . . . . . . . . . . . . . . . . . . . . . . . . 52
Considerations for RAID 10 and 50 on PERC 4/SC,
4/DC, 4e/DC, 4/Di, 4e/Si, and 4e/Di
. . . . . . . . . 53
Comparing RAID Level and Concatenation
Performance
. . . . . . . . . . . . . . . . . . . . . . . 53
No-RAID
. . . . . . . . . . . . . . . . . . . . . . . . . 55