diskdev_cmds/mount.tproj/mount.8

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  32 .\"     @(#)mount.8     8.8 (Berkeley) 6/16/94
  33 .\"
  34 .Dd June 16, 1994
  35 .Dt MOUNT 8
  36 .Os BSD 4
  37 .Sh NAME
  38 .Nm mount
  39 .Nd mount file systems
  40 .Sh SYNOPSIS
  41 .Nm mount
  42 .Op Fl adfruvw
  43 .Op Fl t Ar lfs | external_type
  44 .Nm mount
  45 .Op Fl dfruvw
  46 .Ar special | mount_point
  47 .Nm mount
  48 .Op Fl dfruvw
  49 .Op Fl o Ar options
  50 .Op Fl t Ar lfs | external_type
  51 .Ar special mount_point
  52 .Sh DESCRIPTION
  53 The
  54 .Nm mount
  55 command
  56 calls the
  57 .Xr mount 2
  58 system call to prepare and graft a
  59 .Ar "special device"
  60 or the remote node (rhost:path) on to the file system tree at the point
  61 .Ar mount_point ,
  62 which must be a directory.  If either
  63 .Ar special
  64 or
  65 .Ar mount_point
  66 are not provided, the appropriate information is obtained via the
  67 .Xr getfsent 3
  68 library routines.
  69 .Pp
  70 The system maintains a list of currently mounted file systems.
  71 If no arguments are given to
  72 .Nm mount,
  73 this list is printed.
  74 .Pp
  75 The options are as follows:
  76 .Bl -tag -width indent
  77 .It Fl a
  78 All the filesystems listed via
  79 .Xr getfsent 3
  80 are mounted.
  81 Exceptions are those marked as ``noauto;'' excluded by the
  82 .Fl t
  83 flag (see below); entries that are neither ``ro,'' ``rw,'' or
  84 ``rq;'' ``nfs'' entries that also have ``net'' as an option; and
  85 already-mounted ``nfs'' entries.
  86 .It Fl d
  87 Causes everything to be done except for the actual system call.
  88 This option is useful in conjunction with the
  89 .Fl v
  90 flag to
  91 determine what the
  92 .Nm mount
  93 command is trying to do.
  94 .It Fl f
  95 Forces the revocation of write access when trying to downgrade
  96 a filesystem mount status from read-write to read-only.
  97 .It Fl o
  98 Options are specified with a
  99 .Fl o
 100 flag followed by a comma separated string of options.
 101 The following options are available:
 102 .Bl -tag -width indent
 103 .It async
 104 All
 105 .Tn I/O
 106 to the file system should be done asynchronously.
 107 This can be somewhat dangerous with respect to losing data when faced with
 108 system crashes and power outages.
 109 This is also the default.
 110 It can be avoided with the
 111 .Em noasync
 112 option.
 113 .It force
 114 The same as
 115 .Fl f ;
 116 forces the revocation of write access when trying to downgrade
 117 a filesystem mount status from read-write to read-only.
 118 .It noasync
 119 This filesystem should not force all
 120 .Tn I/O
 121 to be written asynchronously.
 122 .It noauto
 123 This filesystem should be skipped when mount is run with the
 124 .Fl a
 125 flag.
 126 .It nodev
 127 Do not interpret character or block special devices on the file system.
 128 This option is useful for a server that has file systems containing
 129 special devices for architectures other than its own.
 130 .It noexec
 131 Do not allow execution of any binaries on the mounted file system.
 132 This option is useful for a server that has file systems containing
 133 binaries for architectures other than its own.
 134 .It noowners
 135 Ignore the ownership field for the entire volume.
 136 This causes all objects to appear as owned by user ID 99 and group ID 99.
 137 User ID 99 is interpreted as the current effective user ID, while group ID 99
 138 is used directly and translates to ``unknown''.
 139 .It nosuid
 140 Do not allow set-user-identifier or set-group-identifier bits to take effect.
 141 .It rdonly
 142 The same as
 143 .Fl r ;
 144 mount the file system read-only (even the super-user may not write it).
 145 .It sync
 146 All
 147 .Tn I/O
 148 to the file system should be done synchronously.
 149 .It update
 150 The same as
 151 .Fl u ;
 152 indicate that the status of an already mounted file system should be changed.
 153 .It union
 154 Causes the namespace to appear as the union of directories
 155 of the mounted filesystem with corresponding directories in the
 156 underlying filesystem.
 157 Lookups will be done in the mounted filesystem first.
 158 If those operations fail due to a non-existent file the underlying
 159 directory is then accessed.
 160 .It noatime
 161 Do not update the file access time when reading from a file.
 162 This option is useful on file systems where there are large numbers of files
 163 and performance is more critical than updating the file access time (which
 164 is rarely ever important).
 165 .It strictatime
 166 Always update the file access time when reading from a file. Without this option the
 167 filesystem may default to a less strict update mode, where some access time updates
 168 are skipped for performance reasons. This option could be ignored if it is not supported
 169 by the filesystem.
 170 .It nobrowse
 171 This option indicates that the mount point should not be visible
 172 via the GUI (i.e., appear on the Desktop as a separate volume).
 173 .El
 174 .Pp
 175 Any additional options specific to a filesystem type that is not
 176 one of the internally known types (see the
 177 .Fl t
 178 option) may be passed as a comma separated list; these options are
 179 distinguished by a leading
 180 .Dq \&-
 181 (dash).
 182 Options that take a value are specified using the syntax -option=value.
 183 For example, the mount command:
 184 .Bd -literal -offset indent
 185 mount -t hfs -o nosuid,-w,-m=755 /dev/disk2s9 /tmp
 186 .Ed
 187 .Pp
 188 causes
 189 .Nm mount
 190 to execute the equivalent of:
 191 .Bd -literal -offset indent
 192 /sbin/mount_hfs -o nosuid -w -m 755 /dev/disk2s9 /tmp
 193 .Ed
 194 .It Fl r
 195 Mount the file system read-only (even the super-user may not write it).
 196 The same as the
 197 .Dq rdonly
 198 argument to the
 199 .Fl o
 200 option.
 201 .It Fl t Ar "lfs \\*(Ba external type"
 202 The argument following the
 203 .Fl t
 204 is used to indicate the file system type.
 205 There is no default local file system for use with mount. A type must
 206 be specified in order to mount a non-NFS filesystem.
 207 The \fI-t\fP option can be used
 208 to indicate that the actions should only be taken on
 209 filesystems of the specified type.
 210 More than one type may be specified in a comma separated list.
 211 The list of filesystem types can be prefixed with
 212 .Dq no
 213 to specify the filesystem types for which action should
 214 .Em not
 215 be taken.
 216 For example, the
 217 .Nm mount
 218 command:
 219 .Bd -literal -offset indent
 220 mount -a -t nonfs,hfs
 221 .Ed
 222 .Pp
 223 mounts all filesystems except those of type
 224 .Tn NFS
 225 and
 226 .Tn HFS .
 227 .Pp
 228 If the type is not one of the internally known types,
 229 mount will attempt to execute a program in
 230 .Pa /sbin/mount_ Ns Em XXX
 231 where
 232 .Em XXX
 233 is replaced by the type name.
 234 For example, nfs filesystems are mounted by the program
 235 .Pa /sbin/mount_nfs .
 236 .It Fl u
 237 The
 238 .Fl u
 239 flag indicates that the status of an already mounted file
 240 system should be changed.
 241 Any of the options discussed above (the
 242 .Fl o
 243 option)
 244 may be changed;
 245 also a file system can be changed from read-only to read-write
 246 or vice versa.
 247 An attempt to change from read-write to read-only will fail if any
 248 files on the filesystem are currently open for writing unless the
 249 .Fl f
 250 flag is also specified.
 251 The set of options is determined by first extracting the options
 252 for the file system from the
 253 filesystem table (see
 254 .Xr getfsent 3 )
 255 then applying any options specified by the
 256 .Fl o
 257 argument,
 258 and finally applying the
 259 .Fl r
 260 or
 261 .Fl w
 262 option.
 263 .It Fl v
 264 Verbose mode.
 265 .It Fl w
 266 Mount the file system read-write.
 267 .Pp
 268 The options specific to NFS filesystems are described in the
 269 .Xr mount_nfs 8
 270 manual page.
 271 .El
 272 .Sh SEE ALSO
 273 .Xr mount 2 ,
 274 .Xr getfsent 3 ,
 275 .Xr mount_afp 8 ,
 276 .Xr mount_cd9660 8 ,
 277 .Xr mount_cddafs 8 ,
 278 .Xr mount_fdesc 8 ,
 279 .Xr mount_hfs 8 ,
 280 .Xr mount_apfs 8 ,
 281 .Xr mount_msdos 8 ,
 282 .Xr mount_nfs 8 ,
 283 .Xr mount_smbfs 8 ,
 284 .Xr mount_udf 8 ,
 285 .Xr mount_webdav 8 ,
 286 .Xr umount 8
 287 .Sh BUGS
 288 It is possible for a corrupted file system to cause a crash.
 289 .Sh HISTORY
 290 A
 291 .Nm mount
 292 command appeared in
 293 .At v6 .