1.\" Copyright (c) 1980, 1989, 1991, 1993 2.\" The Regents of the University of California. 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.\" @(#)mount.8 8.7 (Berkeley) 3/27/94 33.\" 34.Dd March 27, 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 ufs | lfs | external_type 44.Nm mount 45.Op Fl dfruvw 46.Ar special | node 47.Nm mount 48.Op Fl dfruvw 49.Op Fl o Ar options 50.Op Fl t Ar ufs | lfs | external_type 51.Ar special node 52.Sh DESCRIPTION 53The 54.Nm mount 55command 56calls the 57.Xr mount 2 58system call to prepare and graft a 59.Ar "special device" 60or the remote node (rhost:path) on to the file system tree at the point 61.Ar node . 62If either 63.Ar special 64or 65.Ar node 66are not provided, the appropriate information is taken from the 67.Xr fstab 5 68file. 69.Pp 70The system maintains a list of currently mounted file systems. 71If no arguments are given to 72.Nm mount, 73this list is printed. 74.Pp 75The options are as follows: 76.Bl -tag -width indent 77.It Fl a 78Causes all filesystems listed in 79.Pa /etc/fstab 80(except those with the ``noauto'' option) to be mounted. This is normally 81done during system startup. 82.It Fl d 83Causes everything to be done except for the actual system call. 84This option is useful in conjunction with the 85.Fl v 86flag to 87determine what the 88.Nm mount 89command is trying to do. 90.It Fl f 91Forces the revocation of write access when trying to downgrade 92a filesystem mount status from read-write to read-only. Also 93forces the R/W mount of an unclean filesystem (dangerous; use with 94caution). 95.It Fl o 96Options are specified with a 97.Fl o 98flag followed by a comma separated string of options. 99The following options are available: 100.Bl -tag -width indent 101.It async 102All 103.Tn I/O 104to the file system should be done asynchronously. 105This is a 106.Em dangerous 107flag to set, 108and should not be used unless you are prepared to recreate the file 109system should your system crash. 110.It force 111The same as 112.Fl f ; 113forces the revocation of write access when trying to downgrade 114a filesystem mount status from read-write to read-only. Also 115forces the R/W mount of an unclean filesystem (dangerous; use with caution). 116.It nodev 117Do not interpret character or block special devices on the file system. 118This option is useful for a server that has file systems containing 119special devices for architectures other than its own. 120.It noexec 121Do not allow execution of any binaries on the mounted file system. 122This option is useful for a server that has file systems containing 123binaries for architectures other than its own. 124.It nosuid 125Do not allow set-user-identifier or set-group-identifier bits to take effect. 126.It rdonly 127The same as 128.Fl r ; 129mount the file system read-only (even the super-user may not write it). 130.It sync 131All 132.Tn I/O 133to the file system should be done synchronously. 134.It update 135The same as 136.Fl u ; 137indicate that the status of an already mounted file system should be changed. 138.It union 139Causes the namespace at the mount point to appear as the union 140of the mounted filesystem root and the existing directory. 141Lookups will be done in the mounted filesystem first. 142If those operations fail due to a non-existent file the underlying 143directory is then accessed. 144All creates are done in the mounted filesystem. 145.El 146.Pp 147Any additional options specific to a filesystem type that is not 148one of the internally known types (see the 149.Fl t 150option) may be passed as a comma separated list; these options are 151distinguished by a leading 152.Dq \&- 153(dash). 154Options that take a value are specified using the syntax -option=value. 155For example, the mount command: 156.Bd -literal -offset indent 157mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp 158.Ed 159.Pp 160causes 161.Nm mount 162to execute the equivalent of: 163.Bd -literal -offset indent 164/sbin/mount_mfs -o nosuid -N -s 4000 /dev/dk0b /tmp 165.Ed 166.It Fl r 167The file system is to be mounted read-only. 168Mount the file system read-only (even the super-user may not write it). 169The same as the 170.Dq rdonly 171argument to the 172.Fl o 173option. 174.It Fl t Ar "ufs \\*(Ba lfs \\*(Ba external type" 175The argument following the 176.Fl t 177is used to indicate the file system type. 178The type 179.Ar ufs 180is the default. 181The 182.Fl t 183option can be used 184to indicate that the actions should only be taken on 185filesystems of the specified type. 186More than one type may be specified in a comma separated list. 187The list of filesystem types can be prefixed with 188.Dq no 189to specify the filesystem types for which action should 190.Em not 191be taken. 192For example, the 193.Nm mount 194command: 195.Bd -literal -offset indent 196mount -a -t nonfs,mfs 197.Ed 198.Pp 199mounts all filesystems except those of type 200.Tn NFS 201and 202.Tn MFS . 203.Pp 204If the type is not one of the internally known types, 205mount will attempt to execute a program in 206.Pa /sbin/mount_ Ns Em XXX 207where 208.Em XXX 209is replaced by the type name. 210For example, nfs filesystems are mounted by the program 211.Pa /sbin/mount_nfs . 212.Pp 213Most filesystems will be dynamically loaded by their mount programs 214if not already present in the kernel, using the 215.Xr vfsload 3 216subroutine. Because this mechanism requires writable temporary space, 217the filesystem type containing 218.Pa /tmp 219must be compiled into the kernel, and the filesystems containing 220.Pa /tmp 221and 222.Pa /usr/bin/ld 223must be listed in 224.Pa /etc/fstab 225before any filesystems which might be dynamically loaded. 226.It Fl u 227The 228.Fl u 229flag indicates that the status of an already mounted file 230system should be changed. 231Any of the options discussed above (the 232.Fl o 233option) 234may be changed; 235also a file system can be changed from read-only to read-write 236or vice versa. 237An attempt to change from read-write to read-only will fail if any 238files on the filesystem are currently open for writing unless the 239.Fl f 240flag is also specified. 241The set of options is determined by first extracting the options 242for the file system from the 243.Xr fstab 244table, 245then applying any options specified by the 246.Fl o 247argument, 248and finally applying the 249.Fl r 250or 251.Fl w 252option. 253.It Fl v 254Verbose mode. 255.It Fl w 256The file system object is to be read and write. 257.Pp 258The options specific to NFS filesystems are described in the 259.Xr mount_nfs 8 260manual page. 261.Sh FILES 262.Bl -tag -width /etc/fstab -compact 263.It Pa /etc/fstab 264file system table 265.El 266.Sh SEE ALSO 267.Xr mount 2 , 268.Xr vfsload 3 , 269.Xr fstab 5 , 270.Xr mount_cd9660 8 , 271.Xr mount_fdesc 8 , 272.Xr mount_kernfs 8 , 273.Xr mount_lfs 8 , 274.Xr mount_lofs 8 , 275.Xr mount_mfs 8 , 276.Xr mount_nfs 8 , 277.Xr mount_null 8 , 278.Xr mount_portal 8 , 279.Xr mount_procfs 8 , 280.Xr mount_umap 8 , 281.Xr mount_union 8 , 282.Xr umount 8 283.Sh BUGS 284It is possible for a corrupted file system to cause a crash. 285.Sh HISTORY 286A 287.Nm mount 288command appeared in 289.At v6 . 290