LSI MegaRAID Express 500 - Manual (Page 3)

Preface iii
Table of Contents
1 Overview .................................................. 1
Single Ended and Differential SCSI Buses....................... 2
Maximum Cable Length for SCSI Standards.................... 2
Documentation.................................................................. 3
MegaRAID Express 500 Block Diagram.......................... 4
2 Introduction to RAID................................ 5
RAID Benefits .................................................................. 5
In This Chapter ................................................................. 6
MegaRAID Express 500 – Host-Based RAID Solution ... 7
RAID Overview................................................................ 8
Fault Tolerance................................................................. 8
Consistency Check............................................................ 8
Disk Rebuild ..................................................................... 9
Hot Spares ...................................................................... 10
Hot Swap ........................................................................ 10
Parity .............................................................................. 11
Disk Striping................................................................... 12
Disk Mirroring................................................................ 13
Disk Spanning................................................................. 14
Logical Drive.................................................................. 15
Logical Drive States ....................................................... 15
SCSI Drive States ........................................................... 15
Disk Array Types............................................................ 16
Enclosure Management................................................... 16
3 RAID Levels............................................ 17
Selecting a RAID Level.................................................. 18
RAID 0 ........................................................................... 19
RAID 1 ........................................................................... 20
RAID 3 ........................................................................... 21
RAID 5 ........................................................................... 23
RAID 10 ......................................................................... 24
RAID 30 ......................................................................... 25
RAID 50 ......................................................................... 26