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Annotated edit history of nfs(5) version 1, including all changes. View license author blame.
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1 perry 1 NFS
2 !!!NFS
3 NAME
4 SYNOPSIS
5 DESCRIPTION
6 FILES
7 SEE ALSO
8 AUTHOR
9 BUGS
10 ----
11 !!NAME
12
13
14 nfs - nfs fstab format and options
15 !!SYNOPSIS
16
17
18 __/etc/fstab__
19 !!DESCRIPTION
20
21
22 The ''fstab'' file contains information about which
23 filesystems to mount where and with what options. For NFS
24 mounts, it contains the server name and exported server
25 directory to mount from, the local directory that is the
26 mount point, and the NFS specific options that control the
27 way the filesystem is mounted.
28
29
30 Here is an example from an ''/etc/fstab'' file from an
31 NFS mount.
32
33
34 server:/usr/local/pub /pub nfs rsize=8192,wsize=8192,timeo=14,intr
35
36
37 __Options__
38
39
40 ''rsize=n'' The number of bytes NFS uses when reading
41 files from an NFS server. The default value is dependent on
42 the kernel, currently 1024 bytes. (However, throughput is
43 improved greatly by asking for
44 ''rsize=8192''.)
45
46
47 ''wsize=n'' The number of bytes NFS uses when writing
48 files to an NFS server. The default value is dependent on
49 the kernel, currently 1024 bytes. (However, throughput is
50 improved greatly by asking for
51 ''wsize=8192''.)
52
53
54 ''timeo=n'' The value in tenths of a second before
55 sending the first retransmission after an RPC timeout. The
56 default value is 7 tenths of a second. After the first
57 timeout, the timeout is doubled after each successive
58 timeout until a maximum timeout of 60 seconds is reached or
59 the enough retransmissions have occured to cause a major
60 timeout. Then, if the filesystem is hard mounted, each new
61 timeout cascade restarts at twice the initial value of the
62 previous cascade, again doubling at each retransmission. The
63 maximum timeout is always 60 seconds. Better overall
64 performance may be achieved by increasing the timeout when
65 mounting on a busy network, to a slow server, or through
66 several routers or gateways.
67
68
69 ''retrans=n''
70
71
72 The number of minor timeouts and retransmissions that must
73 occur before a major timeout occurs. The default is 3
74 timeouts. When a major timeout occurs, the file operation is
75 either aborted or a
76
77
78 ''acregmin=n''
79
80
81 The minimum time in seconds that attributes of a regular
82 file should be cached before requesting fresh information
83 from a server. The default is 3 seconds.
84
85
86 ''acregmax=n''
87
88
89 The maximum time in seconds that attributes of a regular
90 file can be cached before requesting fresh information from
91 a server. The default is 60 seconds.
92
93
94 ''acdirmin=n''
95
96
97 The minimum time in seconds that attributes of a directory
98 should be cached before requesting fresh information from a
99 server. The default is 30 seconds.
100
101
102 ''acdirmax=n''
103
104
105 The maximum time in seconds that attributes of a directory
106 can be cached before requesting fresh information from a
107 server. The default is 60 seconds.
108
109
110 ''actimeo=n''
111
112
113 Using actimeo sets all of ''acregmin, acregmax,
114 acdirmin,'' and ''acdirmax'' to the same value. There
115 is no default value.
116
117
118 ''retry=n'' The number of minutes to retry an NFS mount
119 operation in the foreground or background before giving up.
120 The default value is 10000 minutes, which is roughly one
121 week.
122
123
124 ''namlen=n''
125
126
127 When an NFS server does not support version two of the RPC
128 mount protocol, this option can be used to specify the
129 maximum length of a filename that is supported on the remote
130 filesystem. This is used to support the POSIX pathconf
131 functions. The default is 255 characters.
132
133
134 ''port=n'' The numeric value of the port to connect to
135 the NFS server on. If the port number is 0 (the default)
136 then query the remote host's portmapper for the port number
137 to use. If the remote host's NFS daemon is not registered
138 with its portmapper, the standard NFS port number 2049 is
139 used instead.
140
141
142 ''mountport=n''
143
144
145 The numeric value of the __mountd__ port.
146
147
148 ''mounthost=name''
149
150
151 The name of the host running __mountd .__
152
153
154 ''mountprog=n''
155
156
157 Use an alternate RPC program number to contact the mount
158 daemon on the remote host. This option is useful for hosts
159 that can run multiple NFS servers. The default value is
160 100005 which is the standard RPC mount daemon program
161 number.
162
163
164 ''mountvers=n''
165
166
167 Use an alternate RPC version number to contact the mount
168 daemon on the remote host. This option is useful for hosts
169 that can run multiple NFS servers. The default value is
170 version 1.
171
172
173 ''nfsprog=n''
174
175
176 Use an alternate RPC program number to contact the NFS
177 daemon on the remote host. This option is useful for hosts
178 that can run multiple NFS servers. The default value is
179 100003 which is the standard RPC NFS daemon program
180 number.
181
182
183 ''nfsvers=n''
184
185
186 Use an alternate RPC version number to contact the NFS
187 daemon on the remote host. This option is useful for hosts
188 that can run multiple NFS servers. The default value is
189 version 2.
190
191
192 ''nolock'' Disable NFS locking. This has to be used with
193 some old NFS servers that don't support
194 locking.
195
196
197 ''bg'' If the first NFS mount attempt times out, retry
198 the mount in the background. After a mount operation is
199 backgrounded, all subsequent mounts on the same NFS server
200 will be backgrounded immediately, without first attempting
201 the mount. A missing mount point is treated as a timeout, to
202 allow for nested NFS mounts.
203
204
205 ''fg'' If the first NFS mount attempt times out, retry
206 the mount in the foreground. This is the complement of the
207 ''bg'' option, and also the default
208 behavior.
209
210
211 ''soft'' If an NFS file operation has a major timeout
212 then report an I/O error to the calling program. The default
213 is to continue retrying NFS file operations
214 indefinitely.
215
216
217 ''hard'' If an NFS file operation has a major timeout
218 then report
219 ''
220
221
222 ''intr'' If an NFS file operation has a major timeout and
223 it is hard mounted, then allow signals to interupt the file
224 operation and cause it to return EINTR to the calling
225 program. The default is to not allow file operations to be
226 interrupted.
227
228
229 ''posix'' Mount the NFS filesystem using POSIX semantics.
230 This allows an NFS filesystem to properly support the POSIX
231 pathconf command by querying the mount server for the
232 maximum length of a filename. To do this, the remote host
233 must support version two of the RPC mount protocol. Many NFS
234 servers support only version one.
235
236
237 ''nocto'' Suppress the retrieval of new attributes when
238 creating a file.
239
240
241 ''noac'' Disable all forms of attribute caching entirely.
242 This extracts a server performance penalty but it allows two
243 different NFS clients to get reasonable good results when
244 both clients are actively writing to common filesystem on
245 the server.
246
247
248 ''nolock'' Do not use locking. Do not start
249 lockd.
250
251
252 ''tcp'' Mount the NFS filesystem using the TCP protocol
253 instead of the default UDP protocol. Many NFS servers only
254 support UDP.
255
256
257 ''udp'' Mount the NFS filesystem using the UDP protocol.
258 This is the default.
259
260
261 All of the non-value options have corresponding nooption
262 forms. For example, nointr means don't allow file operations
263 to be interrupted.
264 !!FILES
265
266
267 ''/etc/fstab''
268 !!SEE ALSO
269
270
271 fstab(5), mount(8), umount(8),
272 exports(5)
273 !!AUTHOR
274
275
276 !!BUGS
277
278
279 The posix, and nocto options are parsed by mount but
280 currently are silently ignored.
281
282
283 The tcp and namlen options are implemented but are not
284 currently supported by the Linux kernel.
285
286
287 The umount command should notify the server when an NFS
288 filesystem is unmounted.
289 ----
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