2.11BSD/man/cat8/mount.0
MOUNT(8) UNIX Programmer's Manual MOUNT(8)
NAME
mount - mount file systems
SYNOPSIS
mount [ -adfruvw ] [ -t _u_f_s | _e_x_t_e_r_n_a_l__t_y_p_e ]
mount [ -dfruvw ] _s_p_e_c_i_a_l | _n_o_d_e
mount [ -dfruvw ] [ -o _o_p_t_i_o_n_s ] [ -t _u_f_s | _e_x_t_e_r_n_a_l__t_y_p_e ]
_s_p_e_c_i_a_l _n_o_d_e
DESCRIPTION
The mount command calls the mount(2) system call to prepare
and graft a _s_p_e_c_i_a_l _d_e_v_i_c_e 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
appropriate information is taken from the fstab(5) file.
The system maintains a list of currently mounted file sys-
tems. If no arguments are given to mount, this list is
printed.
The options are as follows:
-a Causes everything to be done except for the actual
system call. This option is useful in conjunction
with the
-v flag to determine what the mount command is trying
to do.
-f Forces the revocation of write access when trying
to downgrade a filesystem mount status from read-
write to read-only. For 2.11BSD this flag is
currently not implemented.
-o Options are specified with a -o flag followed by a
comma separated string of options. The following
options are available:
async All I/O to the file system should be
done asynchronously.
This is a dangerous flag to and should
not be used unless system should your
system crash.
force The same as -f; forces the revocation of
write access when trying to downgrade a
filesystem mount status from read-write
to read-only. This is not (and likely
never will be) supported in 2.11BSD.
Printed 11/24/99 November 16, 1996 1
MOUNT(8) UNIX Programmer's Manual MOUNT(8)
noaccesstime
File access times are not updated.
This is a performance optimization for
read-only, short-lived data, e.g., news.
noauto This filesystem should be skipped when
mount is run with the -a flag.
na Same as noauto.
nodev Do not interpret character or block spe-
cial 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.
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 archi-
tectures other than its own.
nosuid Do not allow set-user-identifier or
set-group-identifier bits to take
effect.
rdonly The same as -r; mount the file system
read-only (even the super-user may not
write it).
sync All I/O to the file system should be
done synchronously.
update The same as -u; indicate that the status
of an already mounted file system should
be changed.
Any additional options specific to a filesystem
type that is not one of the internally known types
(see the -t option) may be passed as a comma
separated list; these options are distinguished by
a leading - (dash). Options that take a value are
specified using the syntax -option=value. At
present no 2.11BSD mount options use the following
form, the example has been retained for illustra-
tive purposes only. For example, the mount com-
mand:
mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp
Printed 11/24/99 November 16, 1996 2
MOUNT(8) UNIX Programmer's Manual MOUNT(8)
causes mount to execute the equivalent of:
/sbin/mount_mfs -o nosuid -N -s 4000 /dev/dk0b
/tmp
-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
``rdonly'' argument to the -o option.
-t "_u_f_s | _e_x_t_e_r_n_a_l _t_y_p_e"
The argument following the -t is used to indi-
cate the file system type. The type _u_f_s is the
default. _U_f_s is also the only value supported
by 2.11BSD other than _s_w_a_p. Thus the -t will
rarely be used. 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 for which action should _n_o_t be taken. For
example, the mount 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 replaced by the
type name. For example, mfs filesystems are
mounted by the program /_s_b_i_n/_m_o_u_n_t__m_f_s.
-u The -u flag indicates that the status of an
already mounted file system should be changed.
Any of the options discussed above (the -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 filesys-
tem are currently open for writing unless the -f
flag is also specified. This is currently not
implemented in 2.11BSD. The ability to change
the flags (nodev, nosuid, etc) is however sup-
ported. The set of options is determined by
first extracting the options for the file system
from the _f_s_t_a_b table, then applying any options
specified by the -o argument, and finally apply-
ing the -r or -w option.
Printed 11/24/99 November 16, 1996 3
MOUNT(8) UNIX Programmer's Manual MOUNT(8)
-v Verbose mode.
-w The file system object is to be read and write.
FILES
/etc/fstab
file system table
SEE ALSO
mount(2), fstab(5), umount(8)
BUGS
It is possible for a corrupted file system to cause a crash.
mount and this manpage were ported from 4.4BSD-Lite to
2.11BSD to gain the ability to set the various flags such as
nodev, nosuid and so on. Multiple filesystem types are not
supported and several of the options and flags are not
implemented.
HISTORY
A mount command appeared in Version 6 AT&T UNIX.
Printed 11/24/99 November 16, 1996 4