c783576970
an alternative program to be used for mounting a file system. Ideally, all file systems should be converted to pass string arguments to nmount(), so that /sbin/mount can handle them. However, certain file systems such as FUSE have not done this, and want to have their own userland mount programs. For example, to mount an NTFS file system with the FUSE NTFS driver: mount -t ntfs -o mountprog=/usr/local/bin/ntfs-3g /dev/acd0 /mnt or via an fstab entry: /dev/acd0 /mnt ntfs ro,noauto,mountprog=/usr/local/bin/ntfs-3g 0 0 PR: 120784 Requested by: Dominic Fandrey
554 lines
15 KiB
Groff
554 lines
15 KiB
Groff
.\" 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.
|
|
.\" 4. 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
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd March 11, 2008
|
|
.Dt MOUNT 8
|
|
.Os
|
|
.Sh NAME
|
|
.Nm mount
|
|
.Nd mount file systems
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl adflpruvw
|
|
.Op Fl F Ar fstab
|
|
.Op Fl o Ar options
|
|
.Op Fl t Cm ufs | Ar external_type
|
|
.Nm
|
|
.Op Fl dfpruvw
|
|
.Ar special | node
|
|
.Nm
|
|
.Op Fl dfpruvw
|
|
.Op Fl o Ar options
|
|
.Op Fl t Cm ufs | Ar external_type
|
|
.Ar special node
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
utility calls the
|
|
.Xr nmount 2
|
|
system call to prepare and graft a
|
|
.Ar special
|
|
device or the remote node (rhost:path) on to the file system tree at the point
|
|
.Ar node .
|
|
If either
|
|
.Ar special
|
|
or
|
|
.Ar node
|
|
are not provided, the appropriate information is taken from the
|
|
.Xr fstab 5
|
|
file.
|
|
.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
|
|
All the file systems described in
|
|
.Xr fstab 5
|
|
are mounted.
|
|
Exceptions are those marked as
|
|
.Dq Li noauto ,
|
|
those marked as
|
|
.Dq Li late
|
|
(unless the
|
|
.Fl l
|
|
option was specified),
|
|
those excluded by the
|
|
.Fl t
|
|
flag (see below), or if they are already mounted (except the
|
|
root file system which is always remounted to preserve
|
|
traditional single user mode behavior).
|
|
.It Fl d
|
|
Causes everything to be done except for the actual system call.
|
|
This option is useful in conjunction with the
|
|
.Fl v
|
|
flag to
|
|
determine what the
|
|
.Nm
|
|
command is trying to do.
|
|
.It Fl F Ar fstab
|
|
Specify the
|
|
.Pa fstab
|
|
file to use.
|
|
.It Fl f
|
|
Forces the revocation of write access when trying to downgrade
|
|
a file system mount status from read-write to read-only.
|
|
Also
|
|
forces the R/W mount of an unclean file system (dangerous; use with
|
|
caution).
|
|
.It Fl l
|
|
When used in conjunction with the
|
|
.Fl a
|
|
option, also mount those file systems which are marked as
|
|
.Dq Li late .
|
|
.It Fl o
|
|
Options are specified with a
|
|
.Fl o
|
|
flag followed by a comma separated string of options.
|
|
In case of conflicting options being specified, the rightmost option
|
|
takes effect.
|
|
The following options are available:
|
|
.Bl -tag -width indent
|
|
.It Cm acls
|
|
Enable Access Control Lists, or ACLS, which can be customized via the
|
|
.Xr setfacl 1
|
|
and
|
|
.Xr getfacl 1
|
|
commands.
|
|
.It Cm async
|
|
All
|
|
.Tn I/O
|
|
to the file system should be done asynchronously.
|
|
This is a
|
|
.Em dangerous
|
|
flag to set, since it does not guarantee that the file system structure
|
|
on the disk will remain consistent.
|
|
For this reason, the
|
|
.Cm async
|
|
flag should be used sparingly, and only when some data recovery
|
|
mechanism is present.
|
|
.It Cm current
|
|
When used with the
|
|
.Fl u
|
|
flag, this is the same as specifying the options currently in effect for
|
|
the mounted file system.
|
|
.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.
|
|
Also
|
|
forces the R/W mount of an unclean file system (dangerous; use with caution).
|
|
.It Cm fstab
|
|
When used with the
|
|
.Fl u
|
|
flag, this is the same as specifying all the options listed in the
|
|
.Xr fstab 5
|
|
file for the file system.
|
|
.It Cm late
|
|
This file system should be skipped when
|
|
.Nm
|
|
is run with the
|
|
.Fl a
|
|
flag but without the
|
|
.Fl l
|
|
flag.
|
|
.It Cm mountprog Ns = Ns Aq Ar program
|
|
Force
|
|
.Nm
|
|
to use the specified program to mount the file system, instead of calling
|
|
.Xr nmount 2
|
|
directly. For example:
|
|
.Bd -literal
|
|
mount -t foofs -o mountprog=/mydir/fooprog /dev/acd0 /mnt
|
|
.Ed
|
|
.It Cm multilabel
|
|
Enable multi-label Mandatory Access Control, or MAC, on the specified file
|
|
system.
|
|
If the file system supports multilabel operation, individual labels will
|
|
be maintained for each object in the file system, rather than using a
|
|
single label for all objects.
|
|
An alternative to the
|
|
.Fl l
|
|
flag in
|
|
.Xr tunefs 8 .
|
|
See
|
|
.Xr mac 4
|
|
for more information, which cause the multilabel mount flag to be set
|
|
automatically at mount-time.
|
|
.It Cm noasync
|
|
Metadata I/O should be done synchronously, while data I/O should be done
|
|
asynchronously.
|
|
This is the default.
|
|
.It Cm noatime
|
|
Do not update the file access time when reading from a file.
|
|
This option
|
|
is useful on file systems where there are large numbers of files and
|
|
performance is more critical than updating the file access time (which is
|
|
rarely ever important).
|
|
This option is currently only supported on local file systems.
|
|
.It Cm noauto
|
|
This file system should be skipped when
|
|
.Nm
|
|
is run with the
|
|
.Fl a
|
|
flag.
|
|
.It Cm noclusterr
|
|
Disable read clustering.
|
|
.It Cm noclusterw
|
|
Disable write clustering.
|
|
.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.
|
|
Note: This option was not designed as a security feature and no
|
|
guarantee is made that it will prevent malicious code execution; for
|
|
example, it is still possible to execute scripts which reside on a
|
|
.Cm noexec
|
|
mounted partition.
|
|
.It Cm nosuid
|
|
Do not allow set-user-identifier or set-group-identifier bits to take effect.
|
|
Note: this option is worthless if a public available suid or sgid
|
|
wrapper like
|
|
.Xr suidperl 1
|
|
is installed on your system.
|
|
It is set automatically when the user does not have super-user privileges.
|
|
.It Cm nosymfollow
|
|
Do not follow symlinks
|
|
on the mounted file system.
|
|
.It Cm ro
|
|
The same as
|
|
.Fl r ;
|
|
mount the file system read-only (even the super-user may not write it).
|
|
.It Cm snapshot
|
|
This option allows a snapshot of the specified file system to be taken.
|
|
The
|
|
.Fl u
|
|
flag is required with this option.
|
|
Note that snapshot files must be created in the file system that is being
|
|
snapshotted.
|
|
You may create up to 20 snapshots per file system.
|
|
Active snapshots are recorded in the superblock, so they persist across unmount
|
|
and remount operations and across system reboots.
|
|
When you are done with a snapshot, it can be removed with the
|
|
.Xr rm 1
|
|
command.
|
|
Snapshots may be removed in any order, however you may not get back all the
|
|
space contained in the snapshot as another snapshot may claim some of the blocks
|
|
that it is releasing.
|
|
Note that the schg flag is set on snapshots to ensure that not even the root
|
|
user can write to them.
|
|
The unlink command makes an exception for snapshot files in that it allows them
|
|
to be removed even though they have the schg flag set, so it is not necessary to
|
|
clear the schg flag before removing a snapshot file.
|
|
.Pp
|
|
Once you have taken a snapshot, there are three interesting things that you can
|
|
do with it:
|
|
.Pp
|
|
.Bl -enum -compact
|
|
.It
|
|
Run
|
|
.Xr fsck 8
|
|
on the snapshot file.
|
|
Assuming that the file system was clean when it was mounted, you should always
|
|
get a clean (and unchanging) result from running fsck on the snapshot.
|
|
This is essentially what the background fsck process does.
|
|
.Pp
|
|
.It
|
|
Run
|
|
.Xr dump 8
|
|
on the snapshot.
|
|
You will get a dump that is consistent with the file system as of the timestamp
|
|
of the snapshot.
|
|
.Pp
|
|
.It
|
|
Mount the snapshot as a frozen image of the file system.
|
|
To mount the snapshot
|
|
.Pa /var/snapshot/snap1 :
|
|
.Bd -literal
|
|
mdconfig -a -t vnode -f /var/snapshot/snap1 -u 4
|
|
mount -r /dev/md4 /mnt
|
|
.Ed
|
|
.Pp
|
|
You can now cruise around your frozen
|
|
.Pa /var
|
|
file system at
|
|
.Pa /mnt .
|
|
Everything will be in the same state that it was at the time the snapshot was
|
|
taken.
|
|
The one exception is that any earlier snapshots will appear as zero length
|
|
files.
|
|
When you are done with the mounted snapshot:
|
|
.Bd -literal
|
|
umount /mnt
|
|
mdconfig -d -u 4
|
|
.Ed
|
|
.Pp
|
|
Further details can be found in the file at
|
|
.Pa /usr/src/sys/ufs/ffs/README.snapshot .
|
|
.El
|
|
.It Cm suiddir
|
|
A directory on the mounted file system will respond to the SUID bit
|
|
being set, by setting the owner of any new files to be the same
|
|
as the owner of the directory.
|
|
New directories will inherit the bit from their parents.
|
|
Execute bits are removed from
|
|
the file, and it will not be given to root.
|
|
.Pp
|
|
This feature is designed for use on fileservers serving PC users via
|
|
ftp, SAMBA, or netatalk.
|
|
It provides security holes for shell users and as
|
|
such should not be used on shell machines, especially on home directories.
|
|
This option requires the SUIDDIR
|
|
option in the kernel to work.
|
|
Only UFS file systems support this option.
|
|
See
|
|
.Xr chmod 2
|
|
for more information.
|
|
.It Cm sync
|
|
All
|
|
.Tn I/O
|
|
to the file system should be done synchronously.
|
|
.It Cm update
|
|
The same as
|
|
.Fl u ;
|
|
indicate that the status of an already mounted file system should be changed.
|
|
.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.
|
|
.El
|
|
.Pp
|
|
Any additional options specific to a file system type that is not
|
|
one of the internally known types (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
|
|
.Nm
|
|
command:
|
|
.Bd -literal -offset indent
|
|
mount -t cd9660 -o -e /dev/cd0 /cdrom
|
|
.Ed
|
|
.Pp
|
|
causes
|
|
.Nm
|
|
to execute the equivalent of:
|
|
.Bd -literal -offset indent
|
|
/sbin/mount_cd9660 -e /dev/cd0 /cdrom
|
|
.Ed
|
|
.Pp
|
|
Additional options specific to file system types
|
|
which are not internally known
|
|
(see the description of the
|
|
.Fl t
|
|
option below)
|
|
may be described in the manual pages for the associated
|
|
.Pa /sbin/mount_ Ns Sy XXX
|
|
utilities.
|
|
.It Fl p
|
|
Print mount information in
|
|
.Xr fstab 5
|
|
format.
|
|
Implies also the
|
|
.Fl v
|
|
option.
|
|
.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
|
|
.Cm ro
|
|
argument to the
|
|
.Fl o
|
|
option.
|
|
.It Fl t Cm ufs | Ar external_type
|
|
The argument following the
|
|
.Fl t
|
|
is used to indicate the file system type.
|
|
The type
|
|
.Cm ufs
|
|
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 Li 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,nullfs
|
|
.Ed
|
|
.Pp
|
|
mounts all file systems except those of type
|
|
.Tn NFS
|
|
and
|
|
.Tn NULLFS .
|
|
.Pp
|
|
The default behavior of
|
|
.Nm
|
|
is to pass the
|
|
.Fl t
|
|
option directly to the
|
|
.Xr nmount 2
|
|
system call in the
|
|
.Li fstype
|
|
option.
|
|
.Pp
|
|
However, for the following file system types:
|
|
.Cm cd9660 ,
|
|
.Cm mfs ,
|
|
.Cm msdosfs ,
|
|
.Cm nfs ,
|
|
.Cm nfs4 ,
|
|
.Cm ntfs ,
|
|
.Cm nwfs ,
|
|
.Cm nullfs ,
|
|
.Cm portalfs ,
|
|
.Cm smbfs ,
|
|
.Cm udf ,
|
|
and
|
|
.Cm unionfs ,
|
|
.Nm
|
|
will not call
|
|
.Xr nmount 2
|
|
directly and will instead attempt to execute a program in
|
|
.Pa /sbin/mount_ Ns Sy XXX
|
|
where
|
|
.Sy XXX
|
|
is replaced by the file system type name.
|
|
For example, nfs file systems are mounted by the program
|
|
.Pa /sbin/mount_nfs .
|
|
.Pp
|
|
Most file systems will be dynamically loaded by the kernel
|
|
if not already present, and if the kernel module is available.
|
|
.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 applying the options specified
|
|
in the argument to
|
|
.Fl o
|
|
and finally applying the
|
|
.Fl r
|
|
or
|
|
.Fl w
|
|
option.
|
|
.It Fl v
|
|
Verbose mode.
|
|
.It Fl w
|
|
The file system object is to be read and write.
|
|
.El
|
|
.Sh ENVIRONMENT
|
|
.Bl -tag -width ".Ev PATH_FSTAB"
|
|
.It Ev PATH_FSTAB
|
|
If the environment variable
|
|
.Ev PATH_FSTAB
|
|
is set, all operations are performed against the specified file.
|
|
.Ev PATH_FSTAB
|
|
will not be honored if the process environment or memory address space is
|
|
considered
|
|
.Dq tainted .
|
|
(See
|
|
.Xr issetugid 2
|
|
for more information.)
|
|
.El
|
|
.Sh FILES
|
|
.Bl -tag -width /etc/fstab -compact
|
|
.It Pa /etc/fstab
|
|
file system table
|
|
.El
|
|
.Sh DIAGNOSTICS
|
|
Various, most of them are self-explanatory.
|
|
.Pp
|
|
.Dl XXXXX file system is not available
|
|
.Pp
|
|
The kernel does not support the respective file system type.
|
|
Note that
|
|
support for a particular file system might be provided either on a static
|
|
(kernel compile-time), or dynamic basis (loaded as a kernel module by
|
|
.Xr kldload 8 ) .
|
|
.Sh SEE ALSO
|
|
.Xr getfacl 1 ,
|
|
.Xr setfacl 1 ,
|
|
.Xr nmount 2 ,
|
|
.Xr acl 3 ,
|
|
.Xr mac 4 ,
|
|
.Xr ext2fs 5 ,
|
|
.Xr fstab 5 ,
|
|
.Xr procfs 5 ,
|
|
.Xr kldload 8 ,
|
|
.Xr mount_cd9660 8 ,
|
|
.Xr mount_msdosfs 8 ,
|
|
.Xr mount_nfs 8 ,
|
|
.Xr mount_ntfs 8 ,
|
|
.Xr mount_nullfs 8 ,
|
|
.Xr mount_nwfs 8 ,
|
|
.Xr mount_portalfs 8 ,
|
|
.Xr mount_smbfs 8 ,
|
|
.Xr mount_udf 8 ,
|
|
.Xr mount_unionfs 8 ,
|
|
.Xr umount 8
|
|
.Sh CAVEATS
|
|
After a successful
|
|
.Nm ,
|
|
the permissions on the original mount point determine if
|
|
.Pa ..\&
|
|
is accessible from the mounted file system.
|
|
The minimum permissions for
|
|
the mount point for traversal across the mount point in both
|
|
directions to be possible for all users is 0111 (execute for all).
|
|
.Pp
|
|
Use of the
|
|
.Nm
|
|
is preferred over the use of the file system specific
|
|
.Pa mount_ Ns Sy XXX
|
|
commands.
|
|
In particular,
|
|
.Xr mountd 8
|
|
gets a
|
|
.Dv SIGHUP
|
|
signal (that causes an update of the export list)
|
|
only when the file system is mounted via
|
|
.Nm .
|
|
.Sh HISTORY
|
|
A
|
|
.Nm
|
|
utility appeared in
|
|
.At v1 .
|
|
.Sh BUGS
|
|
It is possible for a corrupted file system to cause a crash.
|