Name
mount, umount - mount or unmount file systems and remote
resources
Synopsis
mount [-p | -v]
mount [-F FSType] [generic_options] [-o specific_options]
[-O] special | mount_point
mount [-F FSType] [generic_options] [-o specific_options]
[-O] special mount_point
mount -a [-F FSType] [-V] [current_options]
[-o specific_options] [mount_point]...
umount [-f] [-V] [-o specific_options] special | mount_point
umount -a [-f] [-V] [-o specific_options] [mount_point]...
Description
mount attaches a file system to the file system hierarchy at
the mount_point, which is the pathname of a directory. If
mount_point has any contents prior to the mount operation,
these are hidden until the file system is unmounted.
umount unmounts a currently mounted file system, which may
be specified either as a mount_point or as special, the dev-
ice on which the file system resides.
The table of currently mounted file systems can be found by
examining the mounted file system information file. This is
provided by a file system that is usually mounted on
/etc/mnttab. The mounted file system information is
described in mnttab(4). Mounting a file system adds an entry
to the mount table; a umount removes an entry from the
table.
When invoked with both the special and mount_point arguments
and the -F option, mount validates all arguments except for
special and invokes the appropriate FSType-specific mount
module. If invoked with no arguments, mount lists all the
mounted file systems recorded in the mount table,
/etc/mnttab. If invoked with a partial argument list (with
only one of special or mount_point, or with both special or
mount_point specified but not FSType), mount will search
/etc/vfstab for an entry that will supply the missing argu-
ments. If no entry is found, and the special argument starts
with /, the default local file system type specified in
/etc/default/fs will be used. Otherwise the default remote
file system type will be used. The default remote file sys-
tem type is determined by the first entry in the
/etc/dfs/fstypes file. After filling in missing arguments,
mount will invoke the FSType-specific mount module.
For file system types that support it, a file can be mounted
directly as a file system by specifying the full path to the
file as the special argument. In such a case, the nosuid
option is enforced. If specific file system support for such
loopback file mounts is not present, you can still use
lofiadm(1M) to mount a file system image. In this case, no
special options are enforced.
Only a user with sufficient privilege (at least
PRIV_SYS_MOUNT) can mount or unmount file systems using
mount and umount. However, any user can use mount to list
mounted file systems and resources.
Options
-F FSType
Used to specify the FSType on which to operate. The
FSType must be specified or must be determinable from
/etc/vfstab, or by consulting /etc/default/fs or
/etc/dfs/fstypes.
-a [ mount_points. . . ]
Perform mount or umount operations in parallel, when
possible.
If mount points are not specified, mount will mount all
file systems whose /etc/vfstab "mount at boot" field is
yes. If mount points are specified, then /etc/vfstab
"mount at boot" field will be ignored.
If mount points are specified, umount will only umount
those mount points. If none is specified, then umount
will attempt to unmount all file systems in /etc/mnttab,
with the exception of certain system required file sys-
tems: /, /usr, /var, /var/adm, /var/run, /proc, /dev/fd
and /tmp.
-f
Forcibly unmount a file system.
Without this option, umount does not allow a file system
to be unmounted if a file on the file system is busy.
Using this option can cause data loss for open files;
programs which access files after the file system has
been unmounted will get an error (EIO).
-p
Print the list of mounted file systems in the
/etc/vfstab format. Must be the only option specified.
See BUGS.
-v
Print the list of mounted file systems in verbose for-
mat. Must be the only option specified.
-V
Echo the complete command line, but do not execute the
command. umount generates a command line by using the
options and arguments provided by the user and adding to
them information derived from /etc/mnttab. This option
should be used to verify and validate the command line.
generic_options
Options that are commonly supported by most FSType-
specific command modules. The following options are
available:
-m
Mount the file system without making an entry in
/etc/mnttab.
-g
Globally mount the file system. On a clustered sys-
tem, this globally mounts the file system on all
nodes of the cluster. On a non-clustered system this
has no effect.
-o
Specify FSType-specific options in a comma separated
(without spaces) list of suboptions and keyword-
attribute pairs for interpretation by the FSType-
specific module of the command. (See mount_ufs(1M).)
When you use -o with a file system that has an entry
in /etc/vfstab, any mount options entered for that
file system in /etc/vfstab are ignored.
The following options are supported:
devices | nodevices
Allow or disallow the opening of device-special
files. The default is devices.
If you use nosuid in conjunction with devices,
the behavior is equivalent to that of nosuid.
exec | noexec
Allow or disallow executing programs in the file
system. Allow or disallow mmap(2) with PROT_EXEC
for files within the file system. The default is
exec.
loop
Ignored for compatibility.
nbmand | nonbmand
Allow or disallow non-blocking mandatory locking
semantics on this file system. Non-blocking man-
datory locking is disallowed by default.
If the file system is mounted with the nbmand
option, then applications can use the fcntl(2)
interface to place non-blocking mandatory locks
on files and the system enforces those seman-
tics. If you enable this option, it can cause
standards conformant applications to see unex-
pected errors.
To avoid the possibility of obtaining mandatory
locks on system files, do not use the nbmand
option with the following file systems:
/
/usr
/etc
/var
/proc
/dev
/devices
/system/contract
/system/object
/etc/mnttab
/etc/dfs/sharetab
Do not use the remount option to change the
nbmand disposition of the file system. The
nbmand option is mutually exclusive of the glo-
bal option. See -g.
ro | rw
Specify read-only or read-write. The default is
rw.
setuid | nosetuid
Allow or disallow setuid or setgid execution.
The default is setuid.
If you specify setuid in conjunction with
nosuid, the behavior is the same as nosuid.
nosuid is equivalent to nosetuid and nodevices.
When suid or nosuid is combined with setuid or
nosetuid and devices or nodevices, the most res-
trictive options take effect.
This option is highly recommended whenever the
file system is shared by way of NFS with the
root= option. Without it, NFS clients could add
setuid programs to the server or create devices
that could open security holes.
suid | nosuid
Allow or disallow setuid or setgid execution.
The default is suid. This option also allows or
disallows opening any device-special entries
that appear within the filesystem.
nosuid is equivalent to nosetuid and nodevices.
When suid or nosuid is combined with setuid or
nosetuid and devices or nodevices, the most res-
trictive options take effect.
This option is highly recommended whenever the
file system is shared using NFS with the
root=option, because, without it, NFS clients
could add setuid programs to the server, or
create devices that could open security holes.
rstchown | norstchown
Allow or disallow restricted chown. If the file
system is mounted with rstchown, the owner of
the file is prevented from changing the owner ID
of the file. If the file system is mounted with
norstchown, the user can permit ownership
changes for files they own. Only the super-user
or a user with appropriate privilege can arbi-
trarily change owner IDs.
-O
Overlay mount. Allow the file system to be mounted
over an existing mount point, making the underlying
file system inaccessible. If a mount is attempted on
a pre-existing mount point without setting this
flag, the mount will fail, producing the error "dev-
ice busy".
-r
Mount the file system read-only.
Examples
Example 1 Mounting and Unmounting a DVD Image Directly
The following commands mount and unmount a DVD image.
# mount -F hsfs /images/solaris.iso /mnt/solaris-image
# umount /mnt/solaris-image
Usage
See largefile(5) for the description of the behavior of
mount and umount when encountering files greater than or
equal to 2 Gbyte ( 2^31 bytes).
Files
/etc/mnttab
Table of mounted file systems.
/etc/default/fs
Default local file system type. Default values can be
set for the following flags in /etc/default/fs. For
example: LOCAL=ufs
LOCAL:
The default partition for a command if no FSType is
specified.
/etc/vfstab
List of default parameters for each file system.
Attributes
See attributes(5) for descriptions of the following attri-
butes:
tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRI-
BUTE TYPEATTRIBUTE VALUE _ Availabilitysystem/core-os
See Also
lofiadm(1M), mount_hsfs(1M), mount_nfs(1M), mount_pcfs(1M),
mount_smbfs(1M), mount_tmpfs(1M), mount_udfs(1M),
mount_ufs(1M), mountall(1M), umountall(1M), fcntl(2),
mmap(2), mnttab(4), vfstab(4), attributes(5), largefile(5),
privileges(5), lofs(7FS), pcfs(7FS)
Notes
If the directory on which a file system is to be mounted is
a symbolic link, the file system is mounted on the directory
to which the symbolic link refers, rather than on top of the
symbolic link itself.