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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
|
<!DOCTYPE HTML PUBLIC "-//Norman Walsh//DTD DocBook HTML 1.0//EN">
<HTML
><HEAD
><TITLE
>The root filesystem</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet"><LINK
REL="HOME"
TITLE="The Linux System Administrators' Guide"
HREF="book1.html"><LINK
REL="UP"
TITLE="Overview of the Directory Tree"
HREF="c212.html"><LINK
REL="PREVIOUS"
TITLE="Overview of the Directory Tree"
HREF="c212.html"><LINK
REL="NEXT"
TITLE="The /etc directory"
HREF="x338.html"></HEAD
><BODY
BGCOLOR="#FFFFFF"
TEXT="#000000"
><DIV
CLASS="NAVHEADER"
><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>The Linux System Administrators' Guide</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="c212.html"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
>Chapter 3. Overview of the Directory Tree</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="x338.html"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="AEN267"
>The root filesystem</A
></H1
><P
>The root filesystem should generally be small, since
it contains very critical files and a small, infrequently
modified filesystem has a better chance of not getting corrupted.
A corrupted root filesystem will generally mean that the system
becomes unbootable except with special measures (e.g., from a
floppy), so you don't want to risk it.</P
><P
>The root directory generally doesn't contain any files, except
perhaps the standard boot image for the system, usually called
<TT
CLASS="FILENAME"
>/vmlinuz</TT
>. All other files are in subdirectories in the
root filesystems:
<DIV
CLASS="GLOSSLIST"
><DL
><DT
><B
><TT
CLASS="FILENAME"
>/bin</TT
></B
></DT
><DD
><P
>Commands needed during bootup
that might be used by normal users (probably after
bootup).</P
></DD
><DT
><B
><TT
CLASS="FILENAME"
>/sbin</TT
></B
></DT
><DD
><P
>Like <TT
CLASS="FILENAME"
>/bin</TT
>,
but the commands are not intended for normal
users, although they may use them if necessary and
allowed.</P
></DD
><DT
><B
><TT
CLASS="FILENAME"
>/etc</TT
></B
></DT
><DD
><P
>Configuration files specific to the
machine.</P
></DD
><DT
><B
><TT
CLASS="FILENAME"
>/root</TT
></B
></DT
><DD
><P
>The home directory for user
\texttt{root}.</P
></DD
><DT
><B
><TT
CLASS="FILENAME"
>/lib</TT
></B
></DT
><DD
><P
>Shared libraries needed by the programs
on the root filesystem.</P
></DD
><DT
><B
><TT
CLASS="FILENAME"
>/lib/modules</TT
></B
></DT
><DD
><P
>Loadable kernel modules, especially
those that are needed to boot the system when
recovering from disasters (e.g., network and filesystem
drivers).</P
></DD
><DT
><B
><TT
CLASS="FILENAME"
>/dev</TT
></B
></DT
><DD
><P
>Device files.</P
></DD
><DT
><B
><TT
CLASS="FILENAME"
>/tmp</TT
></B
></DT
><DD
><P
>Temporary files. Programs running after
bootup should use <TT
CLASS="FILENAME"
>/var/tmp</TT
>, not
<TT
CLASS="FILENAME"
>/tmp</TT
>, since the former is probably
on a disk with more space.</P
></DD
><DT
><B
><TT
CLASS="FILENAME"
>/boot</TT
></B
></DT
><DD
><P
>Files used by the bootstrap loader,
e.g., LILO. Kernel images are often kept here instead
of in the root directory. If there are many kernel
images, the directory can easily grow rather big, and it
might be better to keep it in a separate filesystem.
Another reason would be to make sure the kernel
images are within the first 1024 cylinders of an IDE
disk.</P
></DD
><DT
><B
><TT
CLASS="FILENAME"
>/mnt</TT
></B
></DT
><DD
><P
>Mount point for temporary mounts by
the system administrator. Programs aren't supposed
to mount on <TT
CLASS="FILENAME"
>/mnt</TT
> automatically.
<TT
CLASS="FILENAME"
>/mnt</TT
> might be divided into
subdirectories (e.g., <TT
CLASS="FILENAME"
>/mnt/dosa</TT
>
might be the floppy drive using an MS-DOS filesystem,
and <TT
CLASS="FILENAME"
>/mnt/exta</TT
> might be the same
with an ext2 filesystem).</P
></DD
><DT
><B
><TT
CLASS="FILENAME"
>/proc</TT
>, <TT
CLASS="FILENAME"
>/usr</TT
>, <TT
CLASS="FILENAME"
>/var</TT
>, <TT
CLASS="FILENAME"
>/home</TT
></B
></DT
><DD
><P
>Mount points for the other
filesystems.</P
></DD
></DL
></DIV
>
</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="c212.html"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="book1.html"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="x338.html"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Overview of the Directory Tree</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="c212.html"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>The <TT
CLASS="FILENAME"
>/etc</TT
> directory</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
|
