MOUNT(8) 386BSD System Manager's Manual MOUNT(8)
NAME
mount, umount - mount and dismount file systems
SYNOPSIS
mount [-afrwu] [-t nfs | ufs | external_type]
mount [-frwu] special| node
mount [-frwu] [-t nfs | ufs | external_type] [| external_type] [-o
options] special node
umount [-af] [-t nfs | ufs | external_type]
umount [-f] special | node
DESCRIPTION
The mount command calls the mount(2) system call to prepare and graft a
special device or the remote node (rhost:path) on to the file system tree
at the point node. If either special or node are not provided, the
appropriate information is taken from the fstab(5) file.
The system maintains a list of currently mounted file systems. If no
arguments are given to mount, this list is printed.
Options available for the mount command:
-F The standard mount options are parsed and passed to external
program via the -F option as a decimal number. (See example
below.)
-f Causes everything to be done except for the actual system call;
if it's not obvious, this ``fakes'' mounting the file system.
This option is useful in conjunction with the -v flag to
determine what the mount command is trying to do.
-o Options are specified with a -o flag followed by a comma
separated 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
architectures other than its own.
synchronous
All I/O to the file system should be done synchronously.
-r The file system object is to be mounted read-only.
-t nfs | ufs | external type
The argument following the -t is used to indicate the file system
type. The type ufs is the default. 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 /usr/libexec/mount_XXX where XXX
is replaced by the type name.
-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. The set of options is determined
by first extracting the options for the file system from the
fstab table, then applying any options specified by the -o
argument, and finally applying the -r or -w option.
-v Verbose mode.
-w 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
-option=value. For example, the mount command:
mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp
causes mount to attempt to execute:
/usr/libexec/mount_mfs -F 8 -N -s 4000 /dev/dk0b /tmp
The following list can be used to override the defaults for an nfs mount:
hard I/O system calls will retry until the server responds (default)
soft I/O system calls will fail and return errno after retrans request
retransmissions
spongy Soft semantics for the stat, lookup, fsstat, readlink and readdir
filesystem operations and hard semantics for the others. This
option is meant to be similar to hard, except that processes will
not be hung forever when they trip over mount points to dead
servers.
bg If the first mount request times out, do retries in background
intr I/O system calls can be interrupted.
noconn Do not connect the socket. Used for UDP servers that send
replies from a socket other than the nfs server socket.
tcp Use TCP transport instead of UDP.
rsize=#
Set read size to # bytes.
wsize=#
Set write size to # bytes.
retry=#
Set mount retry count to #.
retrans=#
Set retransmission count for nfs rpc's to #.
timeo=#
Set initial nfs timeout to # in 0.1 sec intervals.
Umount removes the special device grafted at point node from file system
tree.
Options for the umount command:
-f 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.
-a All of the file systems described in fstab are unmounted.
-t Is used to indicate 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 prefixed with ``no'' to specify the filesystem types
on which no action should be taken. (See example above for the
mount command.)
FILES
/etc/fstab file system table
SEE ALSO
mount(2), unmount(2), fstab(5)
BUGS
It is possible for a corrupted file system to cause a crash.
HISTORY
A mount command appeared in Version 6 AT&T UNIX.
4th Berkeley Distribution August 5, 1991 3