.\" Copyright (c) 1980, 1989, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\" %sccs.include.redist.roff%
.\" @(#)mount.8 8.5 (Berkeley) %G%
.Op Fl t Ar ufs | lfs | external_type
.Op Fl t Ar ufs | lfs | external_type
system call to prepare and graft a
or the remote node (rhost:path) on to the file system tree at the point
are not provided, the appropriate information is taken from the
The system maintains a list of currently mounted file systems.
If no arguments are given to
The options are as follows:
Causes everything to be done except for the actual system call.
This option is useful in conjunction with the
Forces the revocation of write access when trying to downgrade
a filesystem mount status from read-write to read-only.
Options are specified with a
flag followed by a comma separated string of options.
The following options are available:
to the file system should be done asynchronously.
and should not be used unless you are prepared to recreate the file
system should your system crash.
forces the revocation of write access when trying to downgrade
a filesystem mount status from read-write to read-only.
Do not interpret character or block special devices on the file system.
This option is useful for a server that has file systems containing
special devices for architectures other than its own.
Do not allow execution of any binaries on the mounted file system.
This option is useful for a server that has file systems containing
binaries for architectures other than its own.
Do not allow set-user-identifier or set-group-identifier bits to take effect.
mount the file system read-only (even the super-user may not write it).
to the file system should be done synchronously.
indicate that the status of an already mounted file system should be changed.
Causes the namespace at the mount point to appear as the union
of the mounted filesystem root and the existing directory.
Lookups will be done in the mounted filesystem first.
If those operations fail due to a non-existent file the underlying
directory is then accessed.
All creates are done in the mounted filesystem.
Any additional options specific to a filesystem type that is not
one of the internally known types (see the
option) may be passed as a comma separated list; these options are
distinguished by a leading
Options that take a value are specified using the syntax -option=value.
For example, the mount command:
.Bd -literal -offset indent
mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp
to execute the equivalent of:
.Bd -literal -offset indent
/sbin/mount_mfs -o nosuid -N -s 4000 /dev/dk0b /tmp
The file system is to be mounted read-only.
Mount the file system read-only (even the super-user may not write it).
.It Fl t Ar "ufs \\*(Ba lfs \\*(Ba external type"
The argument following the
is used to indicate the file system type.
The \fI-t\fP option can be used
to indicate that the actions should only be taken on
filesystems of the specified type.
More than one type may be specified in a comma separated list.
The list of filesystem types can be prefixed with
to specify the filesystem types for which action should
.Bd -literal -offset indent
mounts all filesystems except those of type
If the type is not one of the internally known types,
mount will attempt to execute a program in
.Pa /sbin/mount_ Ns Em XXX
is replaced by the type name.
For example, nfs filesystems are mounted by the program
flag indicates that the status of an already mounted file
system should be changed.
Any of the options discussed above (the
also a file system can be changed from read-only to read-write
An attempt to change from read-write to read-only will fail if any
files on the filesystem are currently open for writing unless the
The set of options is determined by first extracting the options
for the file system from the
then applying any options specified by the
The file system object is to be read and write.
The options specific to NFS filesystems are described in the
.Bl -tag -width /etc/fstab -compact
It is possible for a corrupted file system to cause a crash.