.\" Copyright (c) 2009-2010 Apple Inc.  All rights reserved.
.\"
.Dd January 19, 2010
.Dt MOUNT_EXFAT 8
.Os Darwin
.Sh NAME
.Nm mount_exfat
.Nd mount an ExFAT file system
.Sh SYNOPSIS
.Nm mount_exfat
.Op Fl o Ar options
.Op Fl u Ar uid
.Op Fl g Ar gid
.Op Fl m Ar mask
.Pa device
.Pa directory
.Sh DESCRIPTION
The
.Nm
command mounts the ExFAT filesystem from the device
.Pa device
onto the directory given by
.Pa directory .
This command is normally invoked by
.Xr diskarbitrationd 8
as the result of detecting a device with a file system recognized as ExFAT.
It can also be invoked indirectly by executing the
.Xr mount 8
command with the
.Fl t Cm exfat
option.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl o Ar options
Use the specified mount
.Ar options ,
as described in
.Xr mount 8 .
.It Fl u Ar uid
Set the owner of the files in the file system to
.Ar uid .
The default owner is the owner of the directory
on which the file system is being mounted.
.It Fl g Ar gid
Set the group of the files in the file system to
.Ar gid .
The default group is the group of the directory
on which the file system is being mounted.
.It Fl m Ar mask
Specify the maximum file permissions for files
in the file system.
(For example, a
.Ar mask
of
.Li 755
specifies that, by default, the owner should have
read, write, and execute permissions for files, but
others should only have read and execute permissions.
See
.Xr chmod 1
for more information about octal file modes.)
Only the nine low-order bits of
.Ar mask
are used.
The default
.Ar mask
is taken from the
directory on which the file system is being mounted.
.El
.Pp
If none of the
.Fl u ,
.Fl g ,
or
.Fl m
options are given, the volume will be mounted with the MNT_UNKNOWNPERMISSIONS
flag (equivalent to the
.Fl o Cm noowners
option).
.Pp
If the device is internal and not removable, the volume will be mounted with
the MNT_ASYNC flag (equivalent to the
.Fl o Cm async
option) by default.
That default can be overridden with the
.Fl o Cm noasync
option.
When mounted with the
.Fl o Cm noasync
option, metadata updates are synced to disk frequently (by default, 50ms after
the system call that changed the metadata returns to its caller).
.Sh SEE ALSO
.Xr fsck_exfat 8 ,
.Xr exfat.util 8 ,
.Xr mount 2 ,
.Xr unmount 2 ,
.Xr fstab 5 ,
.Xr mount 8
.Sh HISTORY
The
.Nm
utility first appeared in Mac OS X 10.6.3.