ntfs-3g.usermap Man page

NTFS-3G.USERMAP(8) System Manager’s Manual NTFS-3G.USERMAP(8)


ntfs-3g.usermap – NTFS Building a User Mapping File


ntfs-3g.usermap windows-system-device [other-ntfs-device…]

Where windows-system-device is the device containing the Windows system
whose users are to be mapped to current Linux system.

And other-ntfs-device is another device containing files which are to
be accessed both by the Windows mentioned above and current Linux sys‐

the ntfs-3g.usermap command must be started as root, and the designated
devices must not be mounted.

Typing ntfs-3g.usermap with no args will display a summary of command


ntfs-3g.usermap creates the file defining the mapping of Windows
accounts to Linux logins for users who owns files which should be visi‐
ble from both Windows and Linux.

It relies on existing files which were created on Windows, trying to
locate significant files and asking which Linux user or group should
own them. When a Linux owner or group is requested, the reply may be :

– the uid or gid (numeric or symbolic) of Linux owner or group of the
In that situation, no more file with the same Windows owner will
be selected.
– or no answer, when not able to define the owner or group.
In that situation another file owned by the same Windows user or
group may be selected later so that a mapping can be defined.

The mappings for standard Windows users, such as “Administrator” or
“All Users” are defined implicitly. As a consequence a user mapping
should never be defined as Linux root.

When there are no more significant files, ntfs-3g.usermap create the
mapping file into the file UserMapping in the current directory. This
file has to be moved to the hidden directory .NTFS-3G in the root of
all the NTFS file systems to be shared between Windows and Linux. This
requires the file system to be mounted, but the created file will not
be taken into account if not present at mount time, which means the
file system has to be unmounted and mounted again for the new mapping
file to be taken into account.


No option is defined for ntfs-3g.usermap.

Map the users defined on the Windows system present on /dev/sda1 :

ntfs-3g.usermap /dev/sda1

A detailed example, with screen displays is available on http://pages‐

ntfs-3g.usermap exits with a value of 0 when no error was detected, and
with a value of 1 when an error was detected.

Please see

NTFS-3G Questions

for common questions and known issues. If you would find a new one in
the latest release of the software then please send an email describing
it in detail. You can contact the development team on the
ntfs-3g-devel@lists.sf.net address.

ntfs-3g.secaudit has been developed by Jean-Pierre André.

Several people made heroic efforts, often over five or more years which
resulted the ntfs-3g driver. Most importantly they are Anton Alta‐
parmakov, Richard Russon, Szabolcs Szakacsits, Yura Pakhuchiy, Yuval
Fledel, and the author of the groundbreaking FUSE filesystem develop‐
ment framework, Miklos Szeredi.


ntfsprogs(8), attr(5), getfattr

ntfs-3g.usermap 1.1.2 February 2010 NTFS-3G.USERMAP(8)