HP 166207-B21 Smart Array 5300 Controller User Guide - Page 109

fault tolerance., RAID ADG-Advanced Data Guarding

Get HP 166207-B21 - Smart Array 5302/32 RAID Controller PDF manuals and user guides
UPC - 720591292225
View all HP 166207-B21 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 109 highlights

Drive Arrays and Fault Tolerance A1 L1 L2 A2 L3 L4 L5 Figure D-4: Two arrays (A1, A2) containing five logical drives spread over five physical drives Each logical drive in an array is distributed over all of the physical drives within the array. A logical drive can also extend over more than one port on the same controller, but it cannot extend over more than one controller. Drive failure, although rare, is potentially catastrophic. In Figure D-4, for example, failure of any physical drive causes all logical drives in the same array to fail, and all data on the drives is lost. To protect against data loss due to physical drive failure, logical drives are configured with fault tolerance. There are several fault-tolerance methods; those supported by current Compaq controllers (and described in the following section) are: • RAID 0-Data Striping only (no fault tolerance) • RAID 1+0-Drive Mirroring • RAID 5-Distributed Data Guarding • RAID ADG-Advanced Data Guarding D-4 Compaq Smart Array 5300 Controller User Guide

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
Drive Arrays and Fault Tolerance
D-4
Compaq Smart Array 5300 Controller User Guide
L4
L5
L3
A1
L1
L2
A2
Figure D-4:
Two arrays (A1, A2) containing five logical
drives spread over five physical drives
Each logical drive in an array is distributed over all of the physical drives within the
array. A logical drive can also extend over more than one port on the same controller,
but it cannot extend over more than one controller.
Drive failure, although rare, is potentially catastrophic. In Figure D-4, for example,
failure of
any
physical drive causes
all
logical drives in the same array to fail, and all
data on the drives is lost.
To protect against data loss due to physical drive failure, logical drives are
configured with
fault tolerance.
There are several fault-tolerance methods; those
supported by current Compaq controllers (and described in the following section) are:
•
RAID 0—Data Striping only (no fault tolerance)
•
RAID 1+0—Drive Mirroring
•
RAID 5—Distributed Data Guarding
•
RAID ADG—Advanced Data Guarding