Fujitsu MPD3173AT Product Manual - Page 178

Spare area, Alternating defective sectors, Sector slip processing

Page 178 highlights

6.4.1 Spare area Following two types of spare area are provided in the user space. 1) Spare sector for sector slip: used for alternating defective sectors at formatting in shipment in case that a physical track contains one or two defective sectors (2 sectors/track) 2) Spare cylinder for alternative assignment: used for alternative assignment for the third and subsequent defective sectors in case that a physical track contains three or more defective sectors, and also used by automatic alternative assignment. (1 cylinder/drive) 6.4.2 Alternating defective sectors The two alternating methods described below are available: (1) Sector slip processing A defective sector is not used and is skipped and a logical sector address is assigned to the subsequent normal sector (physically adjacent sector to the defective sector). When defective sector is present, the sector slip processing is performed in the formatting. Figure 6.7 shows an example where (physical) sector 5 is defective on head 0 in cylinder 0. Index Sector (physical) 12 Cylinder 0 Head 0 34 56 Defective sector 78 12 34 5 6 7 Sector (logical) unused 249086 429097 34008 SP 249075 420968 299 If an access request to sector 5 is specified, the device accesses physical sector 6 instead of sector 5. Figure 6.7 Sector slip processing C141-E069-02EN 6 - 11

  • 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
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191

C141-E069-02EN
6 - 11
6.4.1
Spare area
Following two types of spare area are provided in the user space.
1)
Spare sector for sector slip:
used for alternating defective sectors at formatting in shipment in case that a physical track
contains one or two defective sectors (2 sectors/track)
2)
Spare cylinder for alternative assignment:
used for alternative assignment for the third and subsequent defective sectors in case that a
physical track contains three or more defective sectors, and also used by automatic
alternative assignment. (1 cylinder/drive)
6.4.2
Alternating defective sectors
The two alternating methods described below are available:
(1)
Sector slip processing
A defective sector is not used and is skipped and a logical sector address is assigned to the
subsequent normal sector (physically adjacent sector to the defective sector).
When defective sector is present, the sector slip processing is performed in the formatting.
Figure 6.7 shows an example where (physical) sector 5 is defective on head 0 in cylinder 0.
2
1
Index
Head 0
Defective
sector
If an access request to sector 5 is specified, the device accesses physical sector 6 instead of sector 5.
Sector (physical)
Cylinder 0
4
3
6
5
8
7
2
1
4
3
6
5
7
Figure 6.7
Sector slip processing
408
407
406
405
406
SP
unused