ntfs-3g - Third Generation Read/Write NTFS Driver
ntfs-3g [-o option[,...]]
volume mount_point
mount -t ntfs-3g [-o option[,...]]
volume mount_point
lowntfs-3g [-o option[,...]] volume
mount_point
mount -t lowntfs-3g [-o option[,...]]
volume mount_point
ntfs-3g is an NTFS driver, which can create, remove,
rename, move files, directories, hard links, and streams; it can read and
write files, including streams, sparse files and transparently compressed
files; it can handle special files like symbolic links, devices, and FIFOs;
moreover it provides standard management of file ownership and permissions,
including POSIX ACLs.
It comes in two variants ntfs-3g and lowntfs-3g with
a few differences mentioned below in relevant options descriptions.
The volume to be mounted can be either a block device or an
image file.
On computers which can be dual-booted into Windows or Linux,
Windows has to be fully shut down before booting into Linux, otherwise the
NTFS file systems on internal disks may be left in an inconsistent state and
changes made by Linux may be ignored by Windows.
So, Windows may not be left in hibernation when starting Linux, in
order to avoid inconsistencies. Moreover, the fast restart feature available
on recent Windows systems has to be disabled. This can be achieved by
issuing as an Administrator the Windows command which disables both
hibernation and fast restarting :
If either Windows is hibernated or its fast restart is enabled, partitions on
internal disks are forced to be mounted in read-only mode.
By default, files and directories are owned by the effective user
and group of the mounting process, and everybody has full read, write,
execution and directory browsing permissions. You can also assign
permissions to a single user by using the uid and/or the gid
options together with the umask, or fmask and dmask
options.
Doing so, Windows users have full access to the files created by
ntfs-3g.
But, by setting the permissions option, you can benefit
from the full ownership and permissions features as defined by POSIX.
Moreover, by defining a Windows-to-Linux user mapping, the ownerships and
permissions are even applied to Windows users and conversely.
If ntfs-3g is set setuid-root then non-root users will be
also able to mount volumes.
NTFS supports several filename namespaces: DOS, Win32 and POSIX.
While the ntfs-3g driver handles all of them, it always creates new
files in the POSIX namespace for maximum portability and interoperability
reasons. This means that filenames are case sensitive and all characters are
allowed except '/' and '\0'. This is perfectly legal on Windows, though some
application may get confused. The option windows_names may be used to
apply Windows restrictions to new file names.
NTFS stores all data in streams. Every file has exactly one
unnamed data stream and can have many named data streams. The size of a file
is the size of its unnamed data stream. By default, ntfs-3g will only
read the unnamed data stream.
By using the options "streams_interface=windows", with
the ntfs-3g driver (not possible with lowntfs-3g), you will be able to read
any named data streams, simply by specifying the stream's name after a
colon. For example:
Named data streams act like normal files, so you can read from them, write to
them and even delete them (using rm). You can list all the named data streams
a file has by getting the "ntfs.streams.list" extended attribute.
Below is a summary of the options that ntfs-3g accepts.
- uid=value and
gid=value
- Set the owner and the group of files and directories. The values are
numerical. The defaults are the uid and gid of the current process.
- umask=value
- Set the bitmask of the file and directory permissions that are not
present. The value is given in octal. The default value is 0 which means
full access to everybody.
- fmask=value
- Set the bitmask of the file permissions that are not present. The value is
given in octal. The default value is 0 which means full access to
everybody.
- dmask=value
- Set the bitmask of the directory permissions that are not present. The
value is given in octal. The default value is 0 which means full access to
everybody.
- usermapping=file-name
- Use file file-name as the user mapping file instead of the default
.NTFS-3G/UserMapping. If file-name defines a full path, the
file must be located on a partition previously mounted. If it defines a
relative path, it is interpreted relative to the root of NTFS partition
being mounted.
When a user mapping file is defined, the options
uid=, gid=, umask=, fmask=, dmask= and
silent are ignored.
- permissions
- Set standard permissions on created files and use standard access control.
This option is set by default when a user mapping file is present.
- acl
- Enable setting Posix ACLs on created files and use them for access
control. This option is only available on specific builds. It is set by
default when a user mapping file is present and the permissions
mount option is not set.
- inherit
- When creating a new file, set its initial protections according to
inheritance rules defined in parent directory. These rules deviate from
Posix specifications, but yield a better Windows compatibility. The
permissions option or a valid user mapping file is required for
this option to be effective.
- ro
- Mount filesystem read-only. Useful if Windows is hibernated or the NTFS
journal file is unclean.
- locale=value
- This option can be useful when wanting a language specific locale
environment. It is however discouraged as it leads to files with
untranslatable chars to not be visible.
- force
- This option is obsolete. It has been superseded by the recover and
norecover options.
- recover
- Recover and try to mount a partition which was not unmounted properly by
Windows. The Windows logfile is cleared, which may cause inconsistencies.
Currently this is the default option.
- norecover
- Do not try to mount a partition which was not unmounted properly by
Windows.
- ignore_case
(only with lowntfs-3g)
- Ignore character case when accessing a file (FOO, Foo,
foo, etc. designate the same file). All files are displayed with
lower case in directory listings.
- remove_hiberfile
- When the NTFS volume is hibernated, a read-write mount is denied and a
read-only mount is forced. One needs either to resume Windows and shutdown
it properly, or use this option which will remove the Windows hibernation
file. Please note, this means that the saved Windows session will be
completely lost. Use this option under your own responsibility.
- atime, noatime,
relatime
- The atime option updates inode access time for each access.
The noatime option disables inode access time updates
which can speed up file operations and prevent sleeping (notebook) disks
spinning up too often thus saving energy and disk lifetime.
The relatime option is very similar to noatime.
It updates inode access times relative to modify or change time. The
access time is only updated if the previous access time was earlier than
the current modify or change time. Unlike noatime this option
doesn't break applications that need to know if a file has been read
since the last time it was modified. This is the default behaviour.
- delay_mtime[=
value]
- Only update the file modification time and the file change time of a file
when it is closed or when the indicated delay since the previous update
has elapsed. The argument is a number of seconds, with a default value of
60. This is mainly useful for big files which are kept open for a long
time and written to without changing their size, such as databases or file
system images mounted as loop.
- show_sys_files
- Show the metafiles in directory listings. Otherwise the default behaviour
is to hide the metafiles, which are special files used to store the NTFS
structure. Please note that even when this option is specified,
"$MFT" may not be visible due to a glibc bug. Furthermore,
irrespectively of show_sys_files, all files are accessible by name, for
example you can always do "ls -l '$UpCase'".
- hide_hid_files
- Hide the hidden files and directories in directory listings, the hidden
files and directories being the ones whose NTFS attribute have the hidden
flag set. The hidden files will not be selected when using wildcards in
commands, but all files and directories remain accessible by full name,
for example you can always display the Windows trash bin directory by :
"ls -ld '$RECYCLE.BIN'".
- hide_dot_files
- Set the hidden flag in the NTFS attribute for created files and
directories whose first character of the name is a dot. Such files and
directories normally do not appear in directory listings, and when the
flag is set they do not appear in Windows directory displays either. When
a file is renamed or linked with a new name, the hidden flag is adjusted
to the latest name.
- windows_names
- This option prevents files, directories and extended attributes to be
created with a name not allowed by windows, because
- it contains some not allowed character,
- or the last character is a space or a dot,
- or the name is reserved.
The forbidden characters are the nine characters " * / : < > ? \ |
and those whose code is less than 0x20, and the reserved names are CON, PRN,
AUX, NUL, COM1..COM9, LPT1..LPT9, with no suffix or followed by a dot.
Existing such files can still be read (and renamed).
- allow_other
- This option overrides the security measure restricting file access to the
user mounting the filesystem. This option is only allowed to root, but
this restriction can be overridden by the 'user_allow_other' option in the
/etc/fuse.conf file.
- max_read=value
- With this option the maximum size of read operations can be set. The
default is infinite. Note that the size of read requests is limited anyway
to 32 pages (which is 128kbyte on i386).
- silent
- Do nothing, without returning any error, on chmod and chown operations and
on permission checking errors, when the permissions option is not
set and no user mapping file is defined. This option is on by default, and
when set off (through option no_def_opts) ownership and permissions
parameters have to be set.
- no_def_opts
- By default ntfs-3g acts as if "silent" (ignore permission errors
when permissions are not enabled), "allow_other" (allow any user
to access files) and "nonempty" (allow mounting on non-empty
directories) were set, and "no_def_opts" cancels these default
options.
- streams_interface=value
- This option controls how the user can access Alternate Data Streams (ADS)
or in other words, named data streams. It can be set to, one of
none, windows or xattr. If the option is set to
none, the user will have no access to the named data streams. If it
is set to windows (not possible with lowntfs-3g), then the user can
access them just like in Windows (eg. cat file:stream). If it's set to
xattr, then the named data streams are mapped to xattrs and user
can manipulate them using {get,set}fattr utilities. The default is
xattr.
- user_xattr
- Same as streams_interface=xattr.
- efs_raw
- This option should only be used in backup or restore situation. It changes
the apparent size of files and the behavior of read and write operation so
that encrypted files can be saved and restored without being decrypted.
The user.ntfs.efsinfo extended attribute has also to be saved and
restored for the file to be decrypted.
- compression
- This option enables creating new transparently compressed files in
directories marked for compression. A directory is marked for compression
by setting the bit 11 (value 0x00000800) in its Windows attribute. In such
a directory, new files are created compressed and new subdirectories are
themselves marked for compression. The option and the flag have no effect
on existing files. Currently this is the default option.
- nocompression
- This option disables creating new transparently compressed files in
directories marked for compression. Existing compressed files can still be
read and updated.
- big_writes
- This option prevents fuse from splitting write buffers into 4K chunks,
enabling big write buffers to be transferred from the application in a
single step (up to some system limit, generally 128K bytes).
- debug
- Makes ntfs-3g to print a lot of debug output from libntfs-3g and
FUSE.
- no_detach
- Makes ntfs-3g to not detach from terminal and print some debug
output.
NTFS uses specific ids to record the ownership of files instead of
the uid and gid used by Linux. As a consequence a mapping
between the ids has to be defined for ownerships to be recorded into NTFS
and recognized.
By default, this mapping is fetched from the file
.NTFS-3G/UserMapping located in the NTFS partition. The option
usermapping= may be used to define another location. When the option
permissions is set and no mapping file is found, a default mapping is
used.
Each line in the user mapping file defines a mapping. It is
organized in three fields separated by colons. The first field identifies a
uid, the second field identifies a gid and the third one
identifies the corresponding NTFS id, known as a SID. The uid
and the gid are optional and defining both of them for the same
SID is not recommended.
If no interoperation with Windows is needed, you can use the
option permissions to define a standard mapping. Alternately, you may
define your own mapping by setting a single default mapping with no uid and
gid. In both cases, files created on Linux will appear to Windows as owned
by a foreign user, and files created on Windows will appear to Linux as
owned by root. Just copy the example below and replace the 9 and 10-digit
numbers by any number not greater than 4294967295. The resulting behavior is
the same as the one with the option permission set with no ownership option
and no user mapping file available.
::S-1-5-21-3141592653-589793238-462643383-10000
If a strong interoperation with Windows is needed, the mapping has to be defined
for each user and group known in both system, and the SIDs used by
Windows has to be collected. This will lead to a user mapping file like :
john::S-1-5-21-3141592653-589793238-462643383-1008
mary::S-1-5-21-3141592653-589793238-462643383-1009
:smith:S-1-5-21-3141592653-589793238-462643383-513
::S-1-5-21-3141592653-589793238-462643383-10000
The utility ntfsusermap may be used to create such a user
mapping file.
Mount /dev/sda1 to /mnt/windows:
ntfs-3g /dev/sda1 /mnt/windows
or
mount -t ntfs-3g /dev/sda1 /mnt/windows
Mount the ntfs data partition /dev/sda3 to /mnt/data with standard Linux
permissions applied :
ntfs-3g -o permissions /dev/sda3 /mnt/data
or
mount -t ntfs-3g -o permissions /dev/sda3
/mnt/data
Read-only mount /dev/sda5 to /home/user/mnt and make user with uid 1000 to be
the owner of all files:
ntfs-3g /dev/sda5 /home/user/mnt -o ro,uid=1000
/etc/fstab entry for the above (the sixth and last field has to be zero to avoid
a file system check at boot time) :
/dev/sda5 /home/user/mnt ntfs-3g ro,uid=1000 0 0
Unmount /mnt/windows:
To facilitate the use of the ntfs-3g driver in scripts, an
exit code is returned to give an indication of the mountability status of a
volume. Value 0 means success, and all other ones mean an error. The unique
error codes are documented in the ntfs-3g.probe(8) manual page.
Please see
http://www.tuxera.com/support/
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 was based on and a major improvement to ntfsmount
and libntfs which were written by Yura Pakhuchiy and the Linux-NTFS team.
The improvements were made, the ntfs-3g project was initiated and currently
led by long time Linux-NTFS team developer Szabolcs Szakacsits
(szaka@tuxera.com).
Several people made heroic efforts, often over five or more years
which resulted the ntfs-3g driver. Most importantly they are Anton
Altaparmakov, Jean-Pierre André, Richard Russon, Szabolcs Szakacsits,
Yura Pakhuchiy, Yuval Fledel, and the author of the groundbreaking FUSE
filesystem development framework, Miklos Szeredi.