4.4BSD/usr/share/man/cat8/mount.0

MOUNT(8) BSD System Manager's Manual MOUNT(8)

NNAAMMEE
mmoouunntt, uummoouunntt - mount and dismount file systems

DDEESSCCRRIIPPTTIIOONN
The mmoouunntt command calls the mount(2) system call to prepare and graft a
_s_p_e_c_i_a_l device or the remote node (rhost:path) on to the file system tree
at the point _n_o_d_e_. If either _s_p_e_c_i_a_l or _n_o_d_e are not provided, the appro-
priate information is taken from the fstab(5) file.

The system maintains a list of currently mounted file systems. If no ar-
guments are given to mmoouunntt,, this list is printed.

Options available for the mmoouunntt command:

--FF The standard mount options are parsed and passed to external pro-
gram via the --FF option as a decimal number. (See example below.)

--dd Causes everything to be done except for the actual system call.
This option is useful in conjunction with the --vv flag to deter-
mine what the mmoouunntt command is trying to do.

--ff Forces the revocation of write access when trying to downgrade a
filesystem mount status from read-write to read-only.

--oo Options are specified with a --oo flag followed by a comma separat-
ed string of options. The following options apply to any file
system that is being mounted:

noexec Do not allow execution of any binaries on the mounted
file system. This options is useful for a server that
has file systems containing binaries for architectures
other than its own.

nosuid Do not allow set-user-identifier or set-group-identifier
bits to take effect.

nodev Do not interpret character or block special devices on
the file system. This options is useful for a server
that has file systems containing special devices for ar-
chitectures other than its own.

synchronous
All I/O to the file system should be done synchronously.

union Causes the namespace at the mount point to appear as the
union of the mounted filesystem root and the existing di-
rectory. 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 cre-
ates are done in the mounted filesystem.

--rr The file system object is to be mounted read-only.

--tt _u_f_s | _l_f_s | _e_x_t_e_r_n_a_l _t_y_p_e
The argument following the --tt is used to indicate the file system
type. The type _u_f_s is the default. The _-_t 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 pre-
fixed with ``no'' to specify the filesystem types on which no ac-
tion should be taken. For example, the mmoouunntt command:

mount -a -t nonfs,mfs

mounts all filesystems except those of type NFS and MFS.

If the type is not one of the internally known types, mount will
attempt to execute a program in _/_s_b_i_n_/_m_o_u_n_t___X_X_X where _X_X_X is re-
placed by the type name. For example, nfs filesystems are mount-
ed by the program _/_s_b_i_n_/_m_o_u_n_t___n_f_s.

--uu The --uu flag indicates that the status of an already mounted file
system should be changed. Any of the options discussed above
(the --oo 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
filesystem are currently open for writing unless the --ff flag is
also specified. The set of options is determined by first ex-
tracting the options for the file system from the fstab table,
then applying any options specified by the --oo argument, and fi-
nally applying the --rr or --ww option.

--vv Verbose mode.

--ww The file system object is to be read and write.

-- Any additional options specific to the program can be passed as a
comma separated list; these options are distinguished by starting
with a -- (dash).

Those options that take a value are specified using the syntax -op-
tion=value. For example, the mount command:

mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp

causes mount to attempt to execute:

/sbin/mount_mfs -F 8 -N -s 4000 /dev/dk0b /tmp

The options specific to NFS filesystems are described in the mount_nfs(8)
manual page.

UUmmoouunntt removes the _s_p_e_c_i_a_l device grafted at point _n_o_d_e from file system
tree.

Options for the uummoouunntt command:

--ff The file system is forcibly unmounted. Active special devices
continue to work, but all other files return errors if further
accesses are attempted. The root file system cannot be forcibly
unmounted.

--aa All of the file systems described in fstab(5) are unmounted.

--tt Is used to indicate the actions should only be taken on filesys-
tems 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 ``no'' to specify the filesystem types on which no
action should be taken. (See example above for the mmoouunntt com-
mand.)

FFIILLEESS

/etc/fstab file system table

SSEEEE AALLSSOO
mount(2), unmount(2), fstab(5)

BBUUGGSS
It is possible for a corrupted file system to cause a crash.

HHIISSTTOORRYY
A mmoouunntt command appeared in Version 6 AT&T UNIX.

4th Berkeley Distribution July 11, 1993 3