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 8.8 (Berkeley) 6/16/94 33.\" $FreeBSD: src/sbin/mount/mount.8,v 1.31.2.12 2003/02/23 21:17:42 trhodes Exp $ 34.\" $DragonFly: src/sbin/mount/mount.8,v 1.8 2008/04/23 21:59:22 thomas Exp $ 35.\" 36.Dd February 3, 2009 37.Dt MOUNT 8 38.Os 39.Sh NAME 40.Nm mount 41.Nd mount file systems 42.Sh SYNOPSIS 43.Nm 44.Op Fl adfpruvw 45.Op Fl o Ar options 46.Op Fl t Ar ufs | external_type 47.Nm 48.Op Fl dfpruvw 49.Ar special | node 50.Nm 51.Op Fl dfpruvw 52.Op Fl o Ar options 53.Op Fl t Ar ufs | external_type 54.Ar special node 55.Sh DESCRIPTION 56The 57.Nm 58utility calls the 59.Xr mount 2 60system call to prepare and graft a 61.Ar "special device" 62or the remote node (rhost:path) on to the file system tree at the point 63.Ar node . 64If either 65.Ar special 66or 67.Ar node 68are not provided, the appropriate information is taken from the 69.Xr fstab 5 70file. 71.Pp 72The system maintains a list of currently mounted file systems. 73If no arguments are given to 74.Nm , 75this list is printed. 76.Pp 77The options are as follows: 78.Bl -tag -width indent 79.It Fl a 80All the filesystems described in 81.Xr fstab 5 82are mounted. 83Exceptions are those marked as 84.Dq noauto , 85excluded by the 86.Fl t 87flag (see below), or if they are already mounted (except the 88root filesystem which is always remounted to preserve 89traditional single user mode behavior). 90.It Fl d 91Causes everything to be done except for the actual system call. 92This option is useful in conjunction with the 93.Fl v 94flag to 95determine what the 96.Nm 97command is trying to do. 98.It Fl f 99Forces the revocation of write access when trying to downgrade 100a filesystem mount status from read-write to read-only. 101Also 102forces the R/W mount of an unclean filesystem (dangerous; use with 103caution). 104.It Fl o 105Options are specified with a 106.Fl o 107flag followed by a comma separated string of options. 108In case of conflicting options being specified, the rightmost option 109takes effect. 110The following options are available: 111.Bl -tag -width indent 112.It Cm async 113All 114.Tn I/O 115to the file system should be done asynchronously. 116This is a 117.Em dangerous 118flag to set, 119and should not be used unless you are prepared to recreate the file 120system should your system crash. 121.It Cm current 122When used with the 123.Fl u 124flag, this is the same as specifying the options currently in effect for 125the mounted filesystem. 126.It Cm force 127The same as 128.Fl f ; 129forces the revocation of write access when trying to downgrade 130a filesystem mount status from read-write to read-only. 131Also 132forces the R/W mount of an unclean filesystem (dangerous; use with caution). 133.It Cm fstab 134When used with the 135.Fl u 136flag, this is the same as specifying all the options listed in the 137.Xr fstab 5 138file for the filesystem. 139.It Cm noasync 140Metadata I/O should be done synchronously, while data I/O should be done 141asynchronously. 142This is the default. 143.It Cm noatime 144Do not update the file access time when reading from a file. 145This option 146is useful on filesystems where there are large numbers of files and 147performance is more critical than updating the file access time (which is 148rarely ever important). 149This option is currently only supported on local filesystems. 150.It Cm noauto 151This filesystem should be skipped when 152.Nm 153is run with the 154.Fl a 155flag. 156.It Cm noclusterr 157Disable read clustering. 158.It Cm noclusterw 159Disable write clustering. 160.It Cm nodev 161Do not interpret character or block special devices on the file system. 162This option is useful for a server that has file systems containing 163special devices for architectures other than its own. 164This option is set automatically when the user does not have super-user 165privileges. 166.It Cm noexec 167Do not allow execution of any binaries on the mounted file system. 168This option is useful for a server that has file systems containing 169binaries for architectures other than its own. 170.It Cm nosuid 171Do not allow set-user-identifier or set-group-identifier bits to take effect. 172Note: this option is worthless if a public available suid or sgid 173wrapper like 174.Xr suidperl 1 175is installed on your system. 176It is set automatically when the user does not have super-user privileges. 177.It Cm nosymfollow 178Do not follow symlinks 179on the mounted file system. 180.It Cm rdonly 181The same as 182.Fl r ; 183mount the file system read-only (even the super-user may not write it). 184.It Cm sync 185All 186.Tn I/O 187to the file system should be done synchronously. 188.It Cm suiddir 189A directory on the mounted filesystem will respond to the SUID bit 190being set, by setting the owner of any new files to be the same 191as the owner of the directory. 192New directories will inherit the bit from their parents. 193Execute bits are removed from 194the file, and it will not be given to root. 195.Pp 196This feature is designed for use on fileservers serving PC users via 197ftp, SAMBA, or netatalk. 198It provides security holes for shell users and as 199such should not be used on shell machines, especially on home directories. 200This option requires the SUIDDIR 201option in the kernel to work. 202Only 203.Xr UFS 5 204filesystems support this option. 205See 206.Xr chmod 2 207for more information. 208.It Cm update 209The same as 210.Fl u ; 211indicate that the status of an already mounted file system should be changed. 212.It Cm union 213Causes the namespace at the mount point to appear as the union 214of the mounted filesystem root and the existing directory. 215Lookups will be done in the mounted filesystem first. 216If those operations fail due to a non-existent file the underlying 217directory is then accessed. 218All creates are done in the mounted filesystem. 219.El 220.Pp 221Any additional options specific to a filesystem type that is not 222one of the internally known types (see the 223.Fl t 224option) may be passed as a comma separated list; these options are 225distinguished by a leading 226.Dq \&- 227(dash). 228Options that take a value are specified using the syntax -option=value. 229For example, the 230.Nm 231command: 232.Bd -literal -offset indent 233mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp 234.Ed 235.Pp 236causes 237.Nm 238to execute the equivalent of: 239.Bd -literal -offset indent 240/sbin/mount_mfs -o nosuid -N -s 4000 /dev/dk0b /tmp 241.Ed 242.Pp 243Additional options specific to filesystem types 244which are not internally known 245(see the description of the 246.Fl t 247option below) 248may be described in the manual pages for the associated 249.Pa /sbin/mount_ Ns Sy XXX 250utilities. 251.It Fl p 252Print mount information in 253.Xr fstab 5 254format. 255If fstab is missing or if the freq and passno fields are omitted, 256the default values as described in 257.Xr fstab 5 258are used. 259Implies also the 260.Fl v 261option. 262.It Fl r 263The file system is to be mounted read-only. 264Mount the file system read-only (even the super-user may not write it). 265The same as the 266.Cm rdonly 267argument to the 268.Fl o 269option. 270.It Fl t Ar ufs | external_type 271The argument following the 272.Fl t 273is used to indicate the file system type. 274The type 275.Ar ufs 276is the default. 277The 278.Fl t 279option can be used 280to indicate that the actions should only be taken on 281filesystems of the specified type. 282More than one type may be specified in a comma separated list. 283The list of filesystem types can be prefixed with 284.Dq no 285to specify the filesystem types for which action should 286.Em not 287be taken. 288For example, the 289.Nm 290command: 291.Bd -literal -offset indent 292mount -a -t nonfs,mfs 293.Ed 294.Pp 295mounts all filesystems except those of type 296.Tn NFS 297and 298.Tn MFS . 299.Pp 300If the type is not one of the internally known types, 301.Nm 302will attempt to execute a program in 303.Pa /sbin/mount_ Ns Sy XXX 304where 305.Sy XXX 306is replaced by the type name. 307For example, nfs filesystems are mounted by the program 308.Pa /sbin/mount_nfs . 309.Pp 310Most filesystems will be dynamically loaded by their 311.Nm 312programs 313if not already present in the kernel, using the 314.Xr vfsload 3 315subroutine. 316Because this mechanism requires writable temporary space, 317the filesystem type containing 318.Pa /tmp 319must be compiled into the kernel, and the filesystems containing 320.Pa /tmp 321and 322.Pa /usr/bin/ld 323must be listed in 324.Pa /etc/fstab 325before any filesystems which might be dynamically loaded. 326.It Fl u 327The 328.Fl u 329flag indicates that the status of an already mounted file 330system should be changed. 331Any of the options discussed above (the 332.Fl o 333option) 334may be changed; 335also a file system can be changed from read-only to read-write 336or vice versa. 337An attempt to change from read-write to read-only will fail if any 338files on the filesystem are currently open for writing unless the 339.Fl f 340flag is also specified. 341The set of options is determined by applying the options specified 342in the argument to 343.Fl o 344and finally applying the 345.Fl r 346or 347.Fl w 348option. 349.It Fl v 350Verbose mode. 351.It Fl w 352The file system object is to be read and write. 353.El 354.Sh FILES 355.Bl -tag -width /etc/fstab -compact 356.It Pa /etc/fstab 357file system table 358.El 359.Sh DIAGNOSTICS 360Various, most of them are self-explanatory. 361.Pp 362.Dl XXXXX filesystem is not available 363.Pp 364The kernel does not support the respective filesystem type. 365Note that 366support for a particular filesystem might be provided either on a static 367(kernel compile-time), or dynamic basis (loaded as a kernel module by 368.Xr kldload 8 ) . 369Normally, 370.Nm 371or its subprocesses attempt to dynamically load a filesystem module if 372it has not been configured statically, using 373.Xr vfsload 3 . 374In this case, the above error message can also mean that you did not 375have permission to load the module. 376.Sh SEE ALSO 377.Xr lsvfs 1 , 378.Xr mount 2 , 379.Xr vfsload 3 , 380.Xr fstab 5 , 381.Xr kldload 8 , 382.Xr mount_cd9660 8 , 383.Xr mount_ext2fs 8 , 384.Xr mount_fdesc 8 , 385.Xr mount_hammer 8 , 386.Xr mount_linprocfs 8 , 387.Xr mount_mfs 8 , 388.Xr mount_msdos 8 , 389.Xr mount_nfs 8 , 390.Xr mount_ntfs 8 , 391.Xr mount_null 8 , 392.Xr mount_nwfs 8 , 393.Xr mount_portal 8 , 394.Xr mount_procfs 8 , 395.Xr mount_smbfs 8 , 396.Xr mount_std 8 , 397.Xr mount_udf 8 , 398.Xr mount_union 8 , 399.Xr sysctl 8 , 400.Xr umount 8 401.Sh CAVEATS 402After a successful 403.Nm , 404the permissions on the original mount point determine if 405.Pa ..\& 406is accessible from the mounted file system. 407The minimum permissions for 408the mount point for traversal across the mount point in both 409directions to be possible for all users is 0111 (execute for all). 410.Sh HISTORY 411A 412.Nm 413utility appeared in 414.At v1 . 415.Sh BUGS 416It is possible for a corrupted file system to cause a crash. 417