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1 | .\" Copyright (c) 1980, 1988, 1991 Regents of the University of California. |
2 | .\" All rights reserved. | |
3 | .\" | |
4 | .\" Redistribution and use in source and binary forms, with or without | |
5 | .\" modification, are permitted provided that the following conditions | |
6 | .\" are met: | |
7 | .\" 1. Redistributions of source code must retain the above copyright | |
8 | .\" notice, this list of conditions and the following disclaimer. | |
9 | .\" 2. Redistributions in binary form must reproduce the above copyright | |
10 | .\" notice, this list of conditions and the following disclaimer in the | |
11 | .\" documentation and/or other materials provided with the distribution. | |
12 | .\" 3. All advertising materials mentioning features or use of this software | |
13 | .\" must display the following acknowledgement: | |
14 | .\" This product includes software developed by the University of | |
15 | .\" California, Berkeley and its contributors. | |
16 | .\" 4. Neither the name of the University nor the names of its contributors | |
17 | .\" may be used to endorse or promote products derived from this software | |
18 | .\" without specific prior written permission. | |
19 | .\" | |
20 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
21 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
22 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
23 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
24 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
25 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
26 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
27 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
28 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
29 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
30 | .\" SUCH DAMAGE. | |
31 | .\" | |
32 | .\" @(#)bad144.8 6.7 (Berkeley) 3/16/91 | |
33 | .\" | |
34 | .Dd March 16, 1991 | |
35 | .Dt BAD144 8 | |
36 | .Os BSD 4 | |
37 | .Sh NAME | |
38 | .Nm bad144 | |
39 | .Nd read/write dec standard 144 bad sector information | |
40 | .Sh SYNOPSIS | |
41 | .Nm bad144 | |
42 | .Op Fl c | |
43 | .Op Fl f | |
44 | .Op Fl v | |
45 | .Ar disk | |
46 | .Oo | |
47 | .Ar sno | |
48 | .Op Ar bad ... | |
49 | .Oc | |
50 | .Nm bad144 | |
51 | .Fl a | |
52 | .Op Fl c | |
53 | .Op Fl f | |
54 | .Op Fl v | |
55 | .Ar disk | |
56 | .Op Ar bad ... | |
57 | .Sh DESCRIPTION | |
58 | .Nm Bad144 | |
59 | can be used to inspect the information stored on a disk that is used by | |
60 | the disk drivers to implement bad sector forwarding. | |
61 | .Pp | |
62 | Available options: | |
63 | .Pp | |
64 | .Bl -tag -width Ds | |
65 | .It Fl a | |
66 | The argument list consists of new bad sectors to be added to an existing | |
67 | list. | |
68 | The new sectors are sorted into the list, | |
69 | which must have been in order. | |
70 | Replacement sectors are moved to accommodate the additions; | |
71 | the new replacement sectors are cleared. | |
72 | .It Fl c | |
73 | Forces an attempt to copy the old sector to the replacement, | |
74 | and may be useful when replacing an unreliable sector. | |
75 | .It Fl f | |
76 | For a RP06, RM03, RM05, Fujitsu Eagle, | |
77 | or | |
78 | .Tn SMD | |
79 | disk on a Massbus, the | |
80 | .Fl f | |
81 | option may be used to mark the new bad sectors as ``bad'' | |
82 | by reformatting them as unusable sectors. | |
83 | This option is | |
84 | .Em required unless | |
85 | the sectors have already been marked bad, | |
86 | or the system will not be notified that it should use the replacement sector. | |
87 | This option may be used while running multiuser; it is no longer necessary | |
88 | to perform format operations while running single-user. | |
89 | .It Fl v | |
90 | The entire process is described as it happens in gory detail if | |
91 | .Fl v | |
92 | (verbose) is given. | |
93 | .El | |
94 | .Pp | |
95 | The format of | |
96 | the information is specified by | |
97 | .Tn DEC | |
98 | standard 144, as follows. | |
99 | The bad sector information is located in the first 5 even numbered sectors | |
100 | of the last track of the disk pack. There are five identical copies of | |
101 | the information, described by the | |
102 | .Ar dkbad | |
103 | structure. | |
104 | .Pp | |
105 | Replacement sectors are allocated starting with the first sector before | |
106 | the bad sector information and working backwards towards the beginning | |
107 | of the disk. A maximum of 126 bad sectors are supported. The position | |
108 | of the bad sector in the bad sector table determines the replacement | |
109 | sector to which it corresponds. | |
110 | The bad sectors must be listed in ascending order. | |
111 | .Pp | |
112 | The bad sector information and replacement sectors are conventionally | |
113 | only accessible through the ``c'' file system partition of the disk. If | |
114 | that partition is used for a file system, the user is responsible for | |
115 | making sure that it does not overlap the bad sector information or any | |
116 | replacement sectors. | |
117 | Thus, one track plus 126 sectors must be reserved to allow use | |
118 | of all of the possible bad sector replacements. | |
119 | .Pp | |
120 | The bad sector structure is as follows: | |
121 | .Bd -literal | |
122 | struct dkbad { | |
123 | long bt_csn; /* cartridge serial number */ | |
124 | u_short bt_mbz; /* unused; should be 0 */ | |
125 | u_short bt_flag; /* -1 => alignment cartridge */ | |
126 | struct bt_bad { | |
127 | u_short bt_cyl; /* bad sector cylinder number */ | |
128 | u_short bt_trksec; /* track and sector number */ | |
129 | } bt_bad[126]; | |
130 | }; | |
131 | .Ed | |
132 | .Pp | |
133 | Unused slots in the | |
134 | .Ar bt_bad | |
135 | array are filled with all bits set, a putatively | |
136 | illegal value. | |
137 | .Pp | |
138 | .Nm Bad144 | |
139 | is invoked by giving a device name (e.g. hk0, hp1, etc.). | |
140 | With no optional arguments | |
141 | it reads the first sector of the last track | |
142 | of the corresponding disk and prints out the bad sector information. | |
143 | It issues a warning if the bad sectors are out of order. | |
144 | .Nm Bad144 | |
145 | may also be invoked with a serial number for the pack and a list | |
146 | of bad sectors. | |
147 | It will write the supplied information into all copies | |
148 | of the bad-sector file, replacing any previous information. | |
149 | Note, however, that | |
150 | .Nm bad144 | |
151 | does not arrange for the specified sectors to be marked bad in this case. | |
152 | This procedure should only be used to restore known bad sector information which | |
153 | was destroyed. | |
154 | .Pp | |
155 | It is no longer necessary to reboot to allow the kernel | |
156 | to reread the bad-sector table from the drive. | |
157 | .Sh SEE ALSO | |
158 | .Xr badsect 8 , | |
159 | .Xr format 8 | |
160 | .Sh BUGS | |
161 | It should be possible to format disks on-line under | |
162 | .Tn UNIX . | |
163 | .Pp | |
164 | It should be possible to mark bad sectors on drives of all type. | |
165 | .Pp | |
166 | On an 11/750, | |
167 | the standard bootstrap drivers used to boot the system do | |
168 | not understand bad sectors, | |
169 | handle | |
170 | .Tn ECC | |
171 | errors, or the special | |
172 | .Tn SSE | |
173 | (skip sector) errors of RM80-type disks. | |
174 | This means that none of these errors can occur when reading the file | |
175 | .Pa /vmunix | |
176 | to boot. Sectors 0-15 of the disk drive | |
177 | must also not have any of these errors. | |
178 | .Pp | |
179 | The drivers which write a system core image on disk after a crash do not | |
180 | handle errors; thus the crash dump area must be free of errors and bad | |
181 | sectors. | |
182 | .Sh HISTORY | |
183 | The | |
184 | .Nm | |
185 | command appeared in | |
186 | .Bx 4.1 . |