mount_lofs(1M)

NAME

mount_lofs: mount, umount — mount and unmount LOFS file systems

SYNOPSIS

/usr/sbin/mount [-p|-v]

/usr/sbin/mount -a [-F lofs] [-eQ]

/usr/sbin/mount [-F lofs] [-eQrV] [-o specific_options] {special_directory|directory}

/usr/sbin/mount [-F lofs] [-eQrV] [-o specific_options] special_directory directory

/usr/sbin/umount [-v] [-V] {special_directory|directory}

/usr/sbin/umount -a [-F lofs] [-v]

DESCRIPTION

The mount command mounts LOFS file systems. Only superuser can mount LOFS file systems. Other users can use mount to list mounted file systems.

mount, attaches special_directory, a directory from one of the mounted file systems, to directory, an another directory in one of the mounted file systems. This enables new file systems to be created, which provide access to existing directories or file systems using alternate path names. Both special_directory and directory should already exist. directory will become the root of the newly mounted LOFS file system, containing the file system hierarchy under special_directory. special_directory and directory must be specified as absolute path names. If either special_directory or directory is omitted, mount attempts to determine the missing value from an entry in the /etc/fstab file. mount can be invoked on any removable file system, except /.

If mount is invoked without any arguments, it lists all the mounted file systems from the file system mount table, /etc/mnttab.

The umount command unmounts mounted file systems. Only a superuser can unmount file systems.

Options (mount)

mount recognizes the following options:

-a

Attempt to mount all file systems described in /etc/fstab. All optional fields in /etc/fstab must be included and supported. If -F lofs is specified, all LOFS file systems in /etc/fstab are mounted. If noauto is specified in an entry's option list, this entry is skipped. File systems are not necessarily mounted in the order listed in /etc/fstab.

-e

Verbose mode. Write a message to standard output indicating which file system is being mounted.

-F lofs

Specify the LOFS file system type (see fstyp(1M)).

-l

Limit actions to local file systems only. LOFS is a local file system.

-o specific_options

Specify options specific to the LOFS file system type. specific_options is a list of comma separated suboptions and/or keyword/attribute pairs intended for the LOFS specific module of the command.

The following specific_options are valid on an LOFS file system:

defaults: Use all default options. When used, this must be the only option specified.
ro: Read-only (see WARNINGS below).

-p

Report the list of mounted file systems in the /etc/fstab format.

-Q

Prevent display of error messages resulting from an attempt to mount already mounted file systems.

-r

Mount the specified file system as read-only (see WARNINGS below).

-v

Report the output in a new style. The new style has the file system type and flags displayed in addition to the old output. The directory and special_directory fields are reversed.

-V

Echo the completed command line, but perform no other action. The command line is generated by incorporating the user-specified options and other information derived from /etc/fstab. This option allows the user to verify the command line.

Options (umount)

The umount command recognizes the following options:

-a: Attempt to unmount all file systems described in /etc/mnttab. All optional fields in /etc/mnttab must be included and supported. If -F lofs file system type is specified, all the LOFS file systems in /etc/mnttab are unmounted. File systems are not necessarily unmounted in the order listed in /etc/mnttab.
-F lofs: Specify the LOFS file system type (see fstyp(1M)).
-v: Verbose mode. Write a message to standard output indicating which file system is being unmounted.
-V: Echo the completed command line, but perform no other action. The command line is generated by incorporating the user-specified options and other information derived from /etc/fstab. This option allows the user to verify the command line.

EXAMPLES

Mount an LOFS file system:

mount /usr /tmp/usr 

Mount another LOFS file system:

mount -F lofs /usr/sbin /tmp/sbin 

WARNINGS

LOFS file systems provide the user with numerous applications; however, they may be potentially confusing. LOFS file systems should generally be created by an experienced user.

For LOFS file systems which are mounted read-only, if the underlying file system is mounted writable, certain write operations on the LOFS will succeed. Thus LOFS should not be relied upon to provide a strictly write-only alternative image of a read-write file system.

AUTHOR

mount was developed by HP, AT&T, the University of California, Berkeley, and Sun Microsystems.

FILES

/etc/fstab: Static information about the file systems
/etc/mnttab: Mounted file system table

STANDARDS CONFORMANCE

mount: SVID3