1.\" Copyright (c) 1980, 1989, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.roff% 5.\" 6.\" @(#)mount.8 6.18 (Berkeley) 01/06/92 7.\" 8.Dd 9.Dt MOUNT 8 10.Os BSD 4 11.Sh NAME 12.Nm mount , 13.Nm umount 14.Nd mount and dismount file systems 15.Sh SYNOPSIS 16.Nm mount 17.Op Fl afrwu 18.Op Fl t Ar ufs | lfs | external_type 19.Nm mount 20.Op Fl frwu 21.Ar special | node 22.Nm mount 23.Op Fl frwu 24.Op Fl t Ar ufs | lfs | external_type 25.Op Fl o Ar options 26.Ar special node 27.Nm umount 28.Op Fl af 29.Op Fl t Ar ufs | lfs | external_type 30.Nm umount 31.Op Fl f 32.Ar special | node 33.Sh DESCRIPTION 34The 35.Nm mount 36command 37calls the 38.Xr mount 2 39system call to prepare and graft a 40.Ar special 41device or the remote node 42(rhost:path) 43on to the file system tree at the point 44.Ar node. 45If either 46.Ar special 47or 48.Ar node 49are not provided, the appropriate 50information is taken from the 51.Xr fstab 5 52file. 53.Pp 54The system maintains a list of currently mounted file systems. 55If no arguments are given to 56.Nm mount, 57this list is printed. 58.Pp 59Options available for the 60.Nm mount 61command: 62.Bl -tag -width indent 63.It Fl F 64The standard mount options are parsed and 65passed to external program via the 66.Fl F 67option 68as a decimal number. 69(See example below.) 70.It Fl f 71Causes everything to be done except for the actual system call; if it's 72not obvious, this ``fakes'' mounting the file system. 73This option is useful in conjunction with the 74.Fl v 75flag to 76determine what the 77.Nm mount 78command is trying to do. 79.It Fl o 80Options are specified with a 81.Fl o 82flag 83followed by a comma separated string of options. 84The following options apply to any file system that is being mounted: 85.Bl -tag -width indent 86.It noexec 87Do not allow execution of any binaries on the mounted file system. 88This options is useful for a server that has file systems containing 89binaries for architectures other than its own. 90.It nosuid 91Do not allow set-user-identifier or set-group-identifier bits to take effect. 92.It nodev 93Do not interpret character or block special devices on the file system. 94This options is useful for a server that has file systems containing 95special devices for architectures other than its own. 96.It synchronous 97All 98.Tn I/O 99to the file system should be done synchronously. 100.El 101.It Fl r 102The file system object is to be mounted read-only. 103.It Fl t Ar "ufs \\*(Ba lfs \\*(Ba external type" 104The argument following the 105.Fl t 106is used to indicate the file system type. 107The type 108.Ar ufs 109is the default. 110The \fI-t\fP option can be used 111to indicate that the actions should only be taken on 112filesystems of the specified type. 113More than one type may be specified in a comma separated list. 114The list of filesystem types can be prefixed with ``no'' to 115specify the filesystem types on which no action should be taken. 116For example, the 117.Nm mount 118command: 119.Bd -literal -offset indent 120mount -a -t nonfs,mfs 121.Ed 122.Pp 123mounts all filesystems except those of type 124.Tn NFS 125and 126.Tn MFS . 127.Pp 128If the type is not one of the internally known types, 129mount will attempt to execute a program in 130.Pa /sbin/mount_ Ns Em XXX 131where 132.Em XXX 133is replaced by the type name. 134For example, nfs filesystems are mounted by the program 135.Pa /sbin/mount_nfs . 136.It Fl u 137The 138.Fl u 139flag indicates that the status of an already mounted file 140system should be changed. 141Any of the options discussed above (the 142.Fl o 143option) 144may be changed; 145also a file system can be changed from read-only to read-write. 146The set of options is determined by first extracting the options 147for the file system from the 148.Xr fstab 149table, 150then applying any options specified by the 151.Fl o 152argument, 153and finally applying the 154.Fl r 155or 156.Fl w 157option. 158.It Fl v 159Verbose mode. 160.It Fl w 161The file system object is to be read and write. 162.It Fl 163Any additional options specific to the program can 164be passed as a comma separated list; 165these options are distinguished by starting with a 166.Fl 167(dash). 168.El 169.Pp 170Those options that take a value are specified 171using the syntax -option=value. 172For example, the mount command: 173.Bd -literal -offset indent 174mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp 175.Ed 176.Pp 177causes mount to attempt to execute: 178.Bd -literal -offset indent 179/sbin/mount_mfs -F 8 -N -s 4000 /dev/dk0b /tmp 180.Ed 181.Pp 182The options specific to NFS filesystems are described in the 183.Xr mount_nfs 8 184manual page. 185.Pp 186.Nm Umount 187removes the 188.Ar special 189device grafted at point 190.Ar node 191from file system tree. 192.Pp 193Options for the 194.Nm umount 195command: 196.Bl -tag -width indent 197.It Fl f 198The file system is forcibly unmounted. 199Active special devices continue to work, 200but all other files return errors if further accesses are attempted. 201The root file system cannot be forcibly unmounted. 202.It Fl a 203All of the file systems described in 204.Xr fstab 5 205are unmounted. 206.It Fl t 207Is used to indicate the actions should only be taken on 208filesystems of the specified type. 209More than one type may be specified in a comma separated list. 210The list of filesystem types can be prefixed with ``no'' to 211specify the filesystem types on which no action should be taken. 212(See example above for the 213.Nm mount 214command.) 215.El 216.Sh FILES 217.Bl -tag -width /etc/fstab -compact 218.It Pa /etc/fstab 219file system table 220.El 221.Sh SEE ALSO 222.Xr mount 2 , 223.Xr unmount 2 , 224.Xr fstab 5 225.Sh BUGS 226It is possible for a corrupted file system to cause a crash. 227.Sh HISTORY 228A 229.Nm 230command appeared in 231.At v6 . 232