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 June 10, 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 F Ar fstab 46.Op Fl o Ar options 47.Op Fl t Ar type 48.Nm 49.Op Fl dfpruvw 50.Brq Ar special | node 51.Nm 52.Op Fl dfpruvw 53.Op Fl o Ar options 54.Op Fl t Ar type 55.Ar special node 56.Sh DESCRIPTION 57The 58.Nm 59utility calls the 60.Xr mount 2 61system call to prepare and graft a 62.Ar "special device" 63or the remote node (rhost:path) on to the file system tree at the point 64.Ar node . 65If either 66.Ar special 67or 68.Ar node 69are not provided, the appropriate information is taken from the 70.Xr fstab 5 71file. 72.Pp 73The system maintains a list of currently mounted file systems. 74If no arguments are given to 75.Nm , 76this list is printed. 77.Pp 78The options are as follows: 79.Bl -tag -width indent 80.It Fl a 81All the filesystems described in 82.Xr fstab 5 83are mounted. 84Exceptions are those marked as 85.Dq noauto , 86excluded by the 87.Fl t 88flag (see below), or if they are already mounted (except the 89root filesystem which is always remounted to preserve 90traditional single user mode behavior). 91.It Fl d 92Causes everything to be done except for the actual system call. 93This option is useful in conjunction with the 94.Fl v 95flag to 96determine what the 97.Nm 98command is trying to do. 99.It Fl F Ar fstab 100Specify the 101.Pa fstab 102file to use. 103.It Fl f 104Forces the revocation of write access when trying to downgrade 105a filesystem mount status from read-write to read-only. 106Also 107forces the R/W mount of an unclean filesystem (dangerous; use with 108caution). 109.It Fl o 110Options are specified with a 111.Fl o 112flag followed by a comma separated string of options. 113If a 114.Dq no 115prefix is added or removed from a option name, then meaning is negated. 116In case of conflicting options being specified, the rightmost option 117takes effect. 118The following options are available: 119.Bl -tag -width indent 120.It Cm async 121All 122.Tn I/O 123to the file system should be done asynchronously. 124This is a 125.Em dangerous 126flag to set, 127and should not be used unless you are prepared to recreate the file 128system should your system crash. 129.It Cm current 130When used with the 131.Fl u 132flag, this is the same as specifying the options currently in effect for 133the mounted filesystem. 134.It Cm force 135The same as 136.Fl f ; 137forces the revocation of write access when trying to downgrade 138a filesystem mount status from read-write to read-only. 139Also 140forces the R/W mount of an unclean filesystem (dangerous; use with caution). 141.It Cm fstab 142When used with the 143.Fl u 144flag, this is the same as specifying all the options listed in the 145.Xr fstab 5 146file for the filesystem. 147.It Cm noasync 148Metadata I/O should be done synchronously, while data I/O should be done 149asynchronously. 150This is the default. 151.It Cm noatime 152Do not update the file access time when reading from a file. 153This option 154is useful on filesystems where there are large numbers of files and 155performance is more critical than updating the file access time (which is 156rarely ever important). 157This option is currently only supported on local filesystems. 158.It Cm noauto 159This filesystem should be skipped when 160.Nm 161is run with the 162.Fl a 163flag. 164.It Cm noclusterr 165Disable read clustering. 166.It Cm noclusterw 167Disable write clustering. 168.It Cm nodev 169Do not interpret character or block special devices on the file system. 170This option is useful for a server that has file systems containing 171special devices for architectures other than its own. 172This option is set automatically when the user does not have super-user 173privileges. 174.It Cm noexec 175Do not allow execution of any binaries on the mounted file system. 176This option is useful for a server that has file systems containing 177binaries for architectures other than its own. 178.It Cm nosuid 179Do not allow set-user-identifier or set-group-identifier bits to take effect. 180Note: this option is worthless if a public available suid or sgid 181wrapper like 182.Xr suidperl 1 183is installed on your system. 184It is set automatically when the user does not have super-user privileges. 185.It Cm nosymfollow 186Do not follow symlinks 187on the mounted file system. 188.It Cm rdonly , ro , norw 189The same as 190.Fl r ; 191mount the file system read-only (even the super-user may not write it). 192.It Cm sync 193All 194.Tn I/O 195to the file system should be done synchronously. 196.It Cm suiddir 197A directory on the mounted filesystem will respond to the SUID bit 198being set, by setting the owner of any new files to be the same 199as the owner of the directory. 200New directories will inherit the bit from their parents. 201Execute bits are removed from 202the file, and it will not be given to root. 203.Pp 204This feature is designed for use on fileservers serving PC users via 205ftp, SAMBA, or netatalk. 206It provides security holes for shell users and as 207such should not be used on shell machines, especially on home directories. 208This option requires the SUIDDIR 209option in the kernel to work. 210Only 211.Xr UFS 5 212filesystems support this option. 213See 214.Xr chmod 2 215for more information. 216.It Cm update 217The same as 218.Fl u ; 219indicate that the status of an already mounted file system should be changed. 220.It Cm union 221Causes the namespace at the mount point to appear as the union 222of the mounted filesystem root and the existing directory. 223Lookups will be done in the mounted filesystem first. 224If those operations fail due to a non-existent file the underlying 225directory is then accessed. 226All creates are done in the mounted filesystem. 227.It Cm ignore 228Will be ignored by 229.Xr df 1 . 230.El 231.Pp 232Any additional options specific to a filesystem type that is not 233one of the internally known types (see the 234.Fl t 235option) may be passed as a comma separated list; these options are 236distinguished by a leading 237.Dq \&- 238(dash). 239Options that take a value are specified using the syntax -option=value. 240For example, the 241.Nm 242command: 243.Bd -literal -offset indent 244mount -t mfs -o nosuid,-N,-s=4000 /dev/da0s0b /tmp 245.Ed 246.Pp 247causes 248.Nm 249to execute the equivalent of: 250.Bd -literal -offset indent 251/sbin/mount_mfs -o nosuid -N -s 4000 /dev/da0s0b /tmp 252.Ed 253.Pp 254Additional options specific to filesystem types 255which are not internally known 256(see the description of the 257.Fl t 258option below) 259may be described in the manual pages for the associated 260.Pa /sbin/mount_ Ns Sy XXX 261utilities. 262.It Fl p 263Print mount information in 264.Xr fstab 5 265format. 266If fstab is missing or if the freq and passno fields are omitted, 267the default values as described in 268.Xr fstab 5 269are used. 270Implies also the 271.Fl v 272option. 273.It Fl r 274The file system is to be mounted read-only. 275Mount the file system read-only (even the super-user may not write it). 276The same as the 277.Cm rdonly 278argument to the 279.Fl o 280option. 281.It Fl t Ar type 282The argument following the 283.Fl t 284is used to indicate the file system type. 285The type 286.Cm ufs 287is the default. 288The 289.Fl t 290option can be used 291to indicate that the actions should only be taken on 292filesystems of the specified type. 293More than one type may be specified in a comma separated list. 294The list of filesystem types can be prefixed with 295.Dq no 296to specify the filesystem types for which action should 297.Em not 298be taken. 299For example, the 300.Nm 301command: 302.Bd -literal -offset indent 303mount -a -t nonfs,mfs 304.Ed 305.Pp 306mounts all filesystems except those of type 307.Tn NFS 308and 309.Tn MFS . 310.Pp 311If the type is not the internally known type, 312.Cm ufs , 313.Nm 314will attempt to execute a program in 315.Pa /sbin/mount_ Ns Sy XXX 316where 317.Sy XXX 318is replaced by the type name. 319For example, nfs filesystems are mounted by the program 320.Pa /sbin/mount_nfs . 321.Pp 322Most filesystems will be dynamically loaded by their 323.Nm 324programs 325if not already present in the kernel, using the 326.Xr vfsload 3 327subroutine. 328Because this mechanism requires writable temporary space, 329the filesystem type containing 330.Pa /tmp 331must be compiled into the kernel, and the filesystems containing 332.Pa /tmp 333and 334.Pa /usr/bin/ld 335must be listed in 336.Pa /etc/fstab 337before any filesystems which might be dynamically loaded. 338.It Fl u 339The 340.Fl u 341flag indicates that the status of an already mounted file 342system should be changed. 343Any of the options discussed above (the 344.Fl o 345option) 346may be changed; 347also a file system can be changed from read-only to read-write 348or vice versa. 349An attempt to change from read-write to read-only will fail if any 350files on the filesystem are currently open for writing unless the 351.Fl f 352flag is also specified. 353The set of options is determined by applying the options specified 354in the argument to 355.Fl o 356and finally applying the 357.Fl r 358or 359.Fl w 360option. 361.It Fl v 362Verbose mode. 363.It Fl w 364The file system object is to be read and write. 365.El 366.Sh ENVIRONMENT 367.Bl -tag -width PATH_FSTAB 368.It Pa PATH_FSTAB 369If the environment variable 370.Pa PATH_FSTAB 371is set all operations are performed against the specified file. 372.El 373.Sh FILES 374.Bl -tag -width /etc/fstab -compact 375.It Pa /etc/fstab 376file system table 377.El 378.Sh DIAGNOSTICS 379Various, most of them are self-explanatory. 380.Pp 381.Dl XXXXX filesystem is not available 382.Pp 383The kernel does not support the respective filesystem type. 384Note that 385support for a particular filesystem might be provided either on a static 386(kernel compile-time), or dynamic basis (loaded as a kernel module by 387.Xr kldload 8 ) . 388Normally, 389.Nm 390or its subprocesses attempt to dynamically load a filesystem module if 391it has not been configured statically, using 392.Xr vfsload 3 . 393In this case, the above error message can also mean that you did not 394have permission to load the module. 395.Sh SEE ALSO 396.Xr df 1 , 397.Xr lsvfs 1 , 398.Xr mount 2 , 399.Xr vfsload 3 , 400.Xr UFS 5 , 401.Xr devtab 5 , 402.Xr fstab 5 , 403.Xr kldload 8 , 404.Xr mount_cd9660 8 , 405.Xr mount_devfs 8 , 406.Xr mount_ext2fs 8 , 407.Xr mount_fdesc 8 , 408.Xr mount_hammer 8 , 409.Xr mount_hpfs 8 , 410.Xr mount_linprocfs 8 , 411.Xr mount_mfs 8 , 412.Xr mount_msdos 8 , 413.Xr mount_nfs 8 , 414.Xr mount_ntfs 8 , 415.Xr mount_null 8 , 416.Xr mount_nwfs 8 , 417.Xr mount_portal 8 , 418.Xr mount_procfs 8 , 419.Xr mount_smbfs 8 , 420.Xr mount_std 8 , 421.Xr mount_tmpfs 8 , 422.Xr mount_udf 8 , 423.Xr mount_union 8 , 424.Xr sysctl 8 , 425.Xr umount 8 426.Sh CAVEATS 427After a successful 428.Nm , 429the permissions on the original mount point determine if 430.Pa ..\& 431is accessible from the mounted file system. 432The minimum permissions for 433the mount point for traversal across the mount point in both 434directions to be possible for all users is 0111 (execute for all). 435.Sh HISTORY 436A 437.Nm 438utility appeared in 439.At v1 . 440.Sh BUGS 441It is possible for a corrupted file system to cause a crash. 442