man/man8/mount.8

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 MOUNT 8 "Sep 8, 2015"
 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_points...]


umount [-f] [-V] [-o specific_options] special | mount_point


umount -a [-f] [-V] [-o specific_options] [mount_points...]


 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 device 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(5). 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 arguments. 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 system 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(8) 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 systems: /, /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 format. 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 system, 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(8).) 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 mandatory 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 semantics. If you enable this option, it
can cause standards conformant applications to see unexpected 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 global
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 restrictive 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 restrictive 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.


-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 "device 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(7) 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.


 SEE ALSO

lofiadm(8), mount_hsfs(8), mount_nfs(8),
mount_pcfs(8), fcntl(2),
 mmap (2),  lofs (4FS),  pcfs (4FS),  mnttab (5),  vfstab (5),  attributes (7),  largefile (7),  privileges (7),  mount_smbfs (8),  mount_tmpfs (8),  mount_udfs (8),  mount_ufs (8),  mountall (8),  umountall (8)  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.