899d1b31b2
as discussed on tech-kern quite some time ago.
447 lines
12 KiB
Groff
447 lines
12 KiB
Groff
.\" $NetBSD: mount.8,v 1.52 2006/02/12 01:32:06 chs Exp $
|
|
.\"
|
|
.\" Copyright (c) 1980, 1989, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)mount.8 8.8 (Berkeley) 6/16/94
|
|
.\"
|
|
.Dd February 11, 2006
|
|
.Dt MOUNT 8
|
|
.Os
|
|
.Sh NAME
|
|
.Nm mount
|
|
.Nd mount file systems
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl Aadfruvw
|
|
.Op Fl t Ar type
|
|
.Nm
|
|
.Op Fl dfruvw
|
|
.Ar special | node
|
|
.Nm
|
|
.Op Fl dfruvw
|
|
.Op Fl o Ar options
|
|
.Op Fl t Ar type
|
|
.Ar special node
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
command invokes a file system-specific program to prepare and graft the
|
|
.Ar special
|
|
device or remote node (rhost:path) on to the file system tree at the point
|
|
.Ar node .
|
|
.Pp
|
|
If either
|
|
.Ar special
|
|
or
|
|
.Ar node
|
|
are not provided, the appropriate information is taken from the
|
|
.Xr fstab 5
|
|
file.
|
|
The provided argument is looked up first in the
|
|
.Dq fs_file ,
|
|
then in the
|
|
.Dq fs_spec
|
|
column.
|
|
If the matching entry in
|
|
.Xr fstab 5
|
|
has the string
|
|
.Dq Li from_mount
|
|
as its
|
|
.Dq fs_spec
|
|
field, the device or remote file system already mounted at
|
|
the location specified by
|
|
.Dq fs_spec
|
|
will be used.
|
|
.Pp
|
|
If both
|
|
.Ar special
|
|
and
|
|
.Ar node
|
|
are given, the disklabel is checked for the file system type.
|
|
.Pp
|
|
In
|
|
.Nx ,
|
|
a file system can only be mounted by an ordinary user who owns the
|
|
point
|
|
.Ar node
|
|
and has access to the
|
|
.Ar special
|
|
device (at least read permissions).
|
|
In addition, the
|
|
.Em vfs.generic.usermount
|
|
.Xr sysctl 3
|
|
must be set to 1 to permit file system mounting by ordinary users.
|
|
See also
|
|
.Xr sysctl 8 .
|
|
.Pp
|
|
The system maintains a list of currently mounted file systems.
|
|
If no arguments are given to
|
|
.Nm ,
|
|
this list is printed.
|
|
.Pp
|
|
The options are as follows:
|
|
.Bl -tag -width indent
|
|
.It Fl A
|
|
Causes
|
|
.Nm
|
|
to try to mount all of the file systems listed in the
|
|
.Xr fstab 5
|
|
file except those for which the
|
|
.Dq noauto
|
|
option is specified.
|
|
.It Fl a
|
|
Similar to the
|
|
.Fl A
|
|
flag, except that if a file system (other than the root file system)
|
|
appears to be already mounted,
|
|
.Nm
|
|
will not try to mount it again.
|
|
.Nm
|
|
assumes that a file system is already mounted if a file system with
|
|
the same type is mounted on the given mount point.
|
|
More stringent checks are not possible because some file system types
|
|
report strange values for the mounted-from device for mounted file
|
|
systems.
|
|
.It Fl d
|
|
Causes everything to be done except for the invocation of
|
|
the file system-specific program.
|
|
This option is useful in conjunction with the
|
|
.Fl v
|
|
flag to determine what the
|
|
.Nm
|
|
command is trying to do.
|
|
.It Fl f
|
|
Forces the revocation of write access when trying to downgrade
|
|
a file system mount status from read-write to read-only.
|
|
.It Fl o
|
|
Options are specified with a
|
|
.Fl o
|
|
flag followed by a comma separated string of options.
|
|
The following options are available:
|
|
.Bl -tag -width nocoredump
|
|
.It Cm async
|
|
All
|
|
.Tn I/O
|
|
to the file system should be done asynchronously.
|
|
In the event of a crash,
|
|
.Em "it is impossible for the system to verify the integrity of data on a file system mounted with this option" .
|
|
You should only use this option if you have an application-specific data
|
|
recovery mechanism, or are willing to recreate the file system from scratch.
|
|
.It Cm noasync
|
|
Clear
|
|
.Cm async
|
|
mode.
|
|
.It Cm force
|
|
The same as
|
|
.Fl f ;
|
|
forces the revocation of write access when trying to downgrade
|
|
a file system mount status from read-write to read-only.
|
|
.It Cm getargs
|
|
Retrieves the file system specific mount arguments for the given
|
|
mounted file system and prints them.
|
|
.It Cm hidden
|
|
By setting the
|
|
.Dv MNT_IGNORE
|
|
flag,
|
|
causes the mount point to be excluded from the
|
|
list of file systems shown by default with
|
|
.Xr df 1 .
|
|
.It Cm noatime
|
|
Never update the access time field for files.
|
|
This option is useful for optimizing read performance on file systems
|
|
that are used as news spools.
|
|
.It Cm noauto
|
|
This file system should be skipped when mount is run with the
|
|
.Fl a
|
|
flag.
|
|
.It Cm nocoredump
|
|
Do not allow programs to create crash dumps (core files) on the file system.
|
|
This option can be used to help protect sensitive
|
|
data by keeping core files (which may contain sensitive data)
|
|
from being created on insecure file systems.
|
|
Only core files that would be created by program crashes are
|
|
prevented by use of this flag; the behavior of
|
|
.Xr savecore 8
|
|
is not affected.
|
|
.It Cm nodev
|
|
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.
|
|
.It Cm nodevmtime
|
|
Do not update modification times on device special files.
|
|
This option is useful on laptops
|
|
or other systems that perform power management.
|
|
.It Cm noexec
|
|
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.
|
|
.It Cm nosuid
|
|
Do not allow set-user-identifier or set-group-identifier bits to take effect.
|
|
.It Cm port
|
|
(NFS only) Use the specified NFS port.
|
|
.It Cm rdonly
|
|
The same as
|
|
.Fl r ;
|
|
mount the file system read-only (even the super-user may not write it).
|
|
.It Cm reload
|
|
Reload all incore data for a file system.
|
|
This is used mainly after running
|
|
.Xr fsck 8
|
|
on the root file system and finding things to fix.
|
|
The file system must be mounted read-only.
|
|
All cached meta-data are invalidated, superblock and summary information
|
|
is re-read from disk, all cached inactive vnodes and file data are
|
|
invalidated and all inode data are re-read for all active vnodes.
|
|
.It Cm softdep
|
|
(FFS only) Mount the file system using soft dependencies.
|
|
This means that metadata will not be written immediately,
|
|
but is written in an ordered fashion to keep the
|
|
on-disk state of the file system consistent.
|
|
This results in significant speedups for file create/delete operations.
|
|
This option will be ignored when using the
|
|
.Fl u
|
|
flag and a file system is already mounted read/write.
|
|
This option has gone through moderate to heavy testing,
|
|
but should still be used with care.
|
|
A file system mounted with
|
|
.Cm softdep
|
|
can not be mounted with
|
|
.Cm async .
|
|
It requires the
|
|
.Dv SOFTDEP
|
|
option to be enabled in the running kernel.
|
|
.It Cm symperm
|
|
Recognize permission of symbolic link when reading or traversing link.
|
|
.It Cm sync
|
|
All
|
|
.Tn I/O
|
|
to the file system should be done synchronously.
|
|
This is not equivalent to the normal mode in which only
|
|
metadata is written synchronously.
|
|
.It Cm nosync
|
|
Clear
|
|
.Cm sync
|
|
mode.
|
|
.It Cm union
|
|
Causes the namespace at the mount point to appear as the union
|
|
of the mounted file system root and the existing directory.
|
|
Lookups will be done in the mounted file system first.
|
|
If those operations fail due to a non-existent file the underlying
|
|
directory is then accessed.
|
|
All creates are done in the mounted file system, except for the fdesc
|
|
file system.
|
|
.It Cm update
|
|
The same as
|
|
.Fl u ;
|
|
indicate that the status of an already mounted file system should be changed.
|
|
.El
|
|
.Pp
|
|
Any additional options specific to a given file system type (see the
|
|
.Fl t
|
|
option) may be passed as a comma separated list; these options are
|
|
distinguished by a leading
|
|
.Dq \&-
|
|
(dash).
|
|
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=32m swap /tmp
|
|
.Ed
|
|
.Pp
|
|
causes
|
|
.Nm
|
|
to execute the equivalent of:
|
|
.Bd -literal -offset indent
|
|
/sbin/mount_mfs -o nosuid -N -s 32m swap /tmp
|
|
.Ed
|
|
.It Fl r
|
|
The file system is to be mounted read-only.
|
|
Mount the file system read-only (even the super-user may not write it).
|
|
The same as the
|
|
.Dq rdonly
|
|
argument to the
|
|
.Fl o
|
|
option.
|
|
.It Fl t Ar type
|
|
The argument following the
|
|
.Fl t
|
|
is used to indicate the file system type.
|
|
The type
|
|
.Ar ffs
|
|
is the default.
|
|
The
|
|
.Fl t
|
|
option can be used to indicate that the actions
|
|
should only be taken on file systems of the specified type.
|
|
More than one type may be specified in a comma separated list.
|
|
The list of file system types can be prefixed with
|
|
.Dq no
|
|
to specify the file system types for which action should
|
|
.Em not
|
|
be taken.
|
|
For example, the
|
|
.Nm
|
|
command:
|
|
.Bd -literal -offset indent
|
|
mount -a -t nonfs,mfs
|
|
.Ed
|
|
.Pp
|
|
mounts all file systems except those of type
|
|
.Tn NFS
|
|
and
|
|
.Tn MFS .
|
|
.Pp
|
|
.Nm
|
|
will attempt to execute a program in
|
|
.Pa /sbin/mount_ Ns Em XXX
|
|
where
|
|
.Em XXX
|
|
is replaced by the type name.
|
|
For example, nfs file systems are mounted by the program
|
|
.Pa /sbin/mount_nfs .
|
|
.It Fl u
|
|
The
|
|
.Fl u
|
|
flag indicates that the status of an already mounted file
|
|
system should be changed.
|
|
Any of the options discussed above (the
|
|
.Fl o
|
|
option)
|
|
may be changed;
|
|
also a file system can be changed from read-only to read-write
|
|
or vice versa.
|
|
An attempt to change from read-write to read-only will fail if any
|
|
files on the file system are currently open for writing unless the
|
|
.Fl f
|
|
flag is also specified.
|
|
The set of options is determined by first extracting the options
|
|
for the file system from the
|
|
.Xr fstab 5
|
|
file, then applying any options specified by the
|
|
.Fl o
|
|
argument,
|
|
and finally applying the
|
|
.Fl r
|
|
or
|
|
.Fl w
|
|
option.
|
|
.It Fl v
|
|
Verbose mode.
|
|
If this flag is specified more than once, then the
|
|
file system-specific mount arguments are printed for the given mounted
|
|
file system.
|
|
.It Fl w
|
|
The file system object is to be read and write.
|
|
.El
|
|
.Pp
|
|
The options specific to the various file system types are
|
|
described in the manual pages for those file systems'
|
|
.Nm mount_XXX
|
|
commands.
|
|
For instance the options specific to Berkeley
|
|
Fast File System (FFS) are described in the
|
|
.Xr mount_ffs 8
|
|
manual page.
|
|
.Pp
|
|
The particular type of file system in each partition of a disk can
|
|
be found by examining the disk label with the
|
|
.Xr disklabel 8
|
|
command.
|
|
.Sh FILES
|
|
.Bl -tag -width /etc/fstab -compact
|
|
.It Pa /etc/fstab
|
|
file system table
|
|
.El
|
|
.Sh EXAMPLES
|
|
Some useful examples:
|
|
.Pp
|
|
.Bl -hang -offset indent -width "MS-DOS"
|
|
.It Tn CD-ROM
|
|
.br
|
|
mount -t cd9660 -r /dev/cd0a /cdrom
|
|
.It Tn MS-DOS
|
|
.br
|
|
mount -t msdos /dev/fd0a /floppy
|
|
.It Tn NFS
|
|
.br
|
|
mount nfs-server-host:/directory/path /mount-point
|
|
.It Tn MFS (32 megabyte)
|
|
.br
|
|
mount -t mfs -o nosuid,-s=32m swap /tmp
|
|
.El
|
|
.Pp
|
|
The
|
|
.Dq noauto
|
|
directive in
|
|
.Pa /etc/fstab
|
|
can be used to make it easy to manually mount and unmount removable
|
|
media using just the mountpoint filename, with an entry like this:
|
|
.Pp
|
|
.Dl /dev/cd0a /cdrom cd9660 ro,noauto 0 0
|
|
.Pp
|
|
That would allow a simple command like
|
|
.Qq mount /cdrom
|
|
or
|
|
.Qq umount /cdrom
|
|
for media using the
|
|
.Tn ISO-9660
|
|
file system format in the first
|
|
.Tn CD-ROM
|
|
drive.
|
|
.Sh SEE ALSO
|
|
.Xr df 1 ,
|
|
.Xr mount 2 ,
|
|
.Xr fstab 5 ,
|
|
.Xr disklabel 8 ,
|
|
.Xr fsck 8 ,
|
|
.Xr mount_ados 8 ,
|
|
.Xr mount_cd9660 8 ,
|
|
.Xr mount_ext2fs 8 ,
|
|
.Xr mount_fdesc 8 ,
|
|
.Xr mount_ffs 8 ,
|
|
.Xr mount_filecore 8 ,
|
|
.Xr mount_kernfs 8 ,
|
|
.Xr mount_lfs 8 ,
|
|
.Xr mount_mfs 8 ,
|
|
.Xr mount_msdos 8 ,
|
|
.Xr mount_nfs 8 ,
|
|
.Xr mount_ntfs 8 ,
|
|
.Xr mount_null 8 ,
|
|
.Xr mount_overlay 8 ,
|
|
.Xr mount_portal 8 ,
|
|
.Xr mount_procfs 8 ,
|
|
.Xr mount_udf 8 ,
|
|
.Xr mount_umap 8 ,
|
|
.Xr mount_union 8 ,
|
|
.Xr umount 8
|
|
.Sh HISTORY
|
|
A
|
|
.Nm
|
|
command appeared in
|
|
.At v6 .
|