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.\" @(#)mount.8 6.17 (Berkeley) 8/5/91
.Nd mount and dismount file systems
.Op Fl t Ar nfs | ufs | external_type
.Op Fl t Ar nfs | ufs | external_type
.Op Fl t Ar nfs | ufs | external_type
system call to prepare and graft a
device or the remote node
on to the file system tree at the point
are not provided, the appropriate
information is taken from the
The system maintains a list of currently mounted file systems.
If no arguments are given to
Options available for the
The standard mount options are parsed and
passed to external program via the
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
Options are specified with a
followed by a comma separated string of options.
The following options apply to any file system that is being mounted:
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.
Do not allow set-user-identifier or set-group-identifier bits to take effect.
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.
Do not create core files on the file system.
to the file system should be done synchronously.
The file system object is to be mounted read-only.
.It Fl t Ar "nfs \\*(Ba ufs \\*(Ba external type"
The argument following the
is used to indicate the file system type.
.Bd -literal -offset indent
mounts all filesystems except those of type
If the type is not one of the internally known types,
mount will attempt to execute a program in
.Pa /sbin/mount_ Ns Em XXX
is replaced by the type name.
flag indicates that the status of an already mounted file
system should be changed.
Any of the options discussed above (the
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
then applying any options specified by the
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
Those options that take a value are specified
using the syntax -option=value.
For example, the mount command:
.Bd -literal -offset indent
mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp
causes mount to attempt to execute:
.Bd -literal -offset indent
/sbin/mount_mfs -F 8 -N -s 4000 /dev/dk0b /tmp
The following list can be used to override
the defaults for an nfs mount:
system calls will retry until the server responds (default)
system calls will fail and return errno after
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.
If the first mount request times out, do retries in background
system calls can be interrupted.
Do not connect the socket.
servers that send replies from a
socket other than the nfs server socket.
Set retransmission count for nfs rpc's to
Set initial nfs timeout to
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.
All of the file systems currently mounted (except the root file
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
.Bl -tag -width /etc/fstab -compact
It is possible for a corrupted file system to cause a crash.