<s>
New	B-Application
Technology	I-Application
File	I-Application
System	I-Application
(	O
NTFS	B-Application
)	O
is	O
a	O
proprietary	B-Application
journaling	B-Application
file	I-Application
system	I-Application
developed	O
by	O
Microsoft	O
.	O
</s>
<s>
Starting	O
with	O
Windows	B-Device
NT	I-Device
3.1	I-Device
,	O
it	O
is	O
the	O
default	O
file	O
system	O
of	O
the	O
Windows	B-Device
NT	I-Device
family	I-Device
.	O
</s>
<s>
It	O
superseded	O
File	B-Application
Allocation	I-Application
Table	I-Application
(	O
FAT	B-Application
)	O
as	O
the	O
preferred	O
filesystem	O
on	O
Windows	O
and	O
is	O
supported	O
in	O
Linux	B-Operating_System
and	O
BSD	B-Operating_System
as	O
well	O
.	O
</s>
<s>
NTFS	B-Application
reading	O
and	O
writing	O
support	O
is	O
provided	O
using	O
a	O
free	B-License
and	I-License
open-source	I-License
kernel	B-Operating_System
implementation	O
known	O
as	O
NTFS3	O
in	O
Linux	B-Operating_System
and	O
the	O
NTFS-3G	B-Application
driver	O
in	O
BSD	B-Operating_System
.	O
</s>
<s>
By	O
using	O
the	O
convert	B-Application
command	O
,	O
Windows	O
can	O
convert	B-Application
FAT32/16/12	O
into	O
NTFS	B-Application
without	O
the	O
need	O
to	O
rewrite	O
all	O
files	O
.	O
</s>
<s>
NTFS	B-Application
uses	O
several	O
files	O
typically	O
hidden	O
from	O
the	O
user	O
to	O
store	O
metadata	O
about	O
other	O
files	O
stored	O
on	O
the	O
drive	O
which	O
can	O
help	O
improve	O
speed	O
and	O
performance	O
when	O
reading	O
data	O
.	O
</s>
<s>
Unlike	O
FAT	B-Application
and	O
High	B-Application
Performance	I-Application
File	I-Application
System	I-Application
(	O
HPFS	B-Application
)	O
,	O
NTFS	B-Application
supports	O
access	O
control	O
lists	O
(	O
ACLs	O
)	O
,	O
filesystem	O
encryption	O
,	O
transparent	O
compression	O
,	O
sparse	B-General_Concept
files	I-General_Concept
and	O
file	B-Application
system	I-Application
journaling	I-Application
.	O
</s>
<s>
NTFS	B-Application
also	O
supports	O
shadow	O
copy	O
to	O
allow	O
backups	O
of	O
a	O
system	O
while	O
it	O
is	O
running	O
,	O
but	O
the	O
functionality	O
of	O
the	O
shadow	O
copies	O
varies	O
between	O
different	O
versions	O
of	O
Windows	O
.	O
</s>
<s>
In	O
the	O
mid-1980s	O
,	O
Microsoft	O
and	O
IBM	O
formed	O
a	O
joint	O
project	O
to	O
create	O
the	O
next	O
generation	O
of	O
graphical	O
operating	B-General_Concept
system	I-General_Concept
;	O
the	O
result	O
was	O
OS/2	B-Application
and	O
HPFS	B-Application
.	O
</s>
<s>
Because	O
Microsoft	O
disagreed	O
with	O
IBM	O
on	O
many	O
important	O
issues	O
,	O
they	O
eventually	O
separated	O
;	O
OS/2	B-Application
remained	O
an	O
IBM	O
project	O
and	O
Microsoft	O
worked	O
to	O
develop	O
Windows	B-Device
NT	I-Device
and	O
NTFS	B-Application
.	O
</s>
<s>
The	O
HPFS	B-Application
file	O
system	O
for	O
OS/2	B-Application
contained	O
several	O
important	O
new	O
features	O
.	O
</s>
<s>
When	O
Microsoft	O
created	O
their	O
new	O
operating	B-General_Concept
system	I-General_Concept
,	O
they	O
"	O
borrowed	O
"	O
many	O
of	O
these	O
concepts	O
for	O
NTFS	B-Application
.	O
</s>
<s>
The	O
original	O
NTFS	B-Application
developers	O
were	O
Tom	O
Miller	O
,	O
Gary	O
Kimura	O
,	O
Brian	O
Andrew	O
,	O
and	O
David	O
Goebel	O
.	O
</s>
<s>
Probably	O
as	O
a	O
result	O
of	O
this	O
common	O
ancestry	O
,	O
HPFS	B-Application
and	O
NTFS	B-Application
use	O
the	O
same	O
disk	B-Application
partition	I-Application
identification	O
type	O
code	O
(	O
07	O
)	O
.	O
</s>
<s>
Using	O
the	O
same	O
Partition	B-Application
ID	O
Record	O
Number	O
is	O
highly	O
unusual	O
,	O
since	O
there	O
were	O
dozens	O
of	O
unused	O
code	O
numbers	O
available	O
,	O
and	O
other	O
major	O
file	O
systems	O
have	O
their	O
own	O
codes	O
.	O
</s>
<s>
For	O
example	O
,	O
FAT	B-Application
has	O
more	O
than	O
nine	O
(	O
one	O
each	O
for	O
FAT12	B-Application
,	O
FAT16	B-Application
,	O
FAT32	B-Application
,	O
etc	O
.	O
)	O
.	O
</s>
<s>
Algorithms	O
identifying	O
the	O
file	O
system	O
in	O
a	O
partition	B-Application
type	O
07	O
must	O
perform	O
additional	O
checks	O
to	O
distinguish	O
between	O
HPFS	B-Application
and	O
NTFS	B-Application
.	O
</s>
<s>
Microsoft	O
has	O
released	O
five	O
versions	O
of	O
NTFS	B-Application
:	O
</s>
<s>
NTFS	B-Application
version	O
number	O
First	O
operating	B-General_Concept
system	I-General_Concept
Release	O
date	O
New	O
features	O
Remarks	O
1.0	O
Windows	B-Device
NT	I-Device
3.1	I-Device
1993	O
Initial	O
version	O
NTFS	B-Application
1.0	O
is	O
incompatible	O
with	O
1.1	O
and	O
newer	O
:	O
volumes	O
written	O
by	O
Windows	B-Device
NT	I-Device
3.5x	O
cannot	O
be	O
read	O
by	O
Windows	B-Device
NT	I-Device
3.1	I-Device
until	O
an	O
update	O
(	O
available	O
on	O
the	O
NT	O
3.5x	O
installation	O
media	O
)	O
is	O
installed	O
.	O
</s>
<s>
1.1	O
Windows	B-Device
NT	I-Device
3.51	I-Device
1995	O
Compressed	B-General_Concept
files	O
,	O
named	O
streams	O
,	O
and	O
access	O
control	O
lists	O
1.2	O
Windows	B-Device
NT	I-Device
4.0	I-Device
1996	O
Security	O
descriptors	O
Commonly	O
called	O
NTFS	B-Application
4.0	O
after	O
the	O
OS	O
release	O
3.0	O
Windows	B-Application
2000	I-Application
2000	O
Disk	B-Application
quotas	I-Application
,	O
file-level	O
encryption	O
in	O
a	O
form	O
of	O
Encrypting	O
File	O
System	O
,	O
sparse	B-General_Concept
files	I-General_Concept
,	O
reparse	B-Application
points	I-Application
,	O
update	O
sequence	O
number	O
(	O
USN	O
)	O
journaling	O
,	O
distributed	O
link	O
tracking	O
,	O
the	O
$Extend	O
folder	O
and	O
its	O
files	O
Compatibility	O
was	O
also	O
made	O
available	O
for	O
Windows	B-Device
NT	I-Device
4.0	I-Device
with	O
the	O
Service	O
Pack	O
4	O
update	O
.	O
</s>
<s>
Commonly	O
called	O
NTFS	B-Application
5.0	O
after	O
the	O
OS	O
release	O
.	O
</s>
<s>
3.1	O
Windows	B-Application
XP	I-Application
October	O
2001	O
Expanded	O
the	O
Master	O
File	O
Table	O
(	O
MFT	O
)	O
entries	O
with	O
redundant	O
MFT	O
record	O
number	O
(	O
useful	O
for	O
recovering	O
damaged	O
MFT	O
files	O
)	O
Commonly	O
called	O
NTFS	B-Application
5.1	O
after	O
the	O
OS	O
release	O
.	O
</s>
<s>
LFS	O
version	O
1.1	O
was	O
replaced	O
by	O
version	O
2.0	O
as	O
of	O
Windows	B-Application
8	I-Application
to	O
improve	O
performance	O
.	O
</s>
<s>
v5.0	O
in	O
Windows	B-Application
2000	I-Application
)	O
is	O
based	O
on	O
the	O
operating	B-General_Concept
system	I-General_Concept
version	O
;	O
it	O
should	O
not	O
be	O
confused	O
with	O
the	O
NTFS	B-Application
version	O
number	O
(	O
v3.1	O
since	O
Windows	B-Application
XP	I-Application
)	O
.	O
</s>
<s>
Although	O
subsequent	O
versions	O
of	O
Windows	O
added	O
new	O
file	O
system-related	O
features	O
,	O
they	O
did	O
not	O
change	O
NTFS	B-Application
itself	O
.	O
</s>
<s>
For	O
example	O
,	O
Windows	B-Application
Vista	I-Application
implemented	O
NTFS	B-Application
symbolic	B-Application
links	I-Application
,	O
Transactional	O
NTFS	B-Application
,	O
partition	B-Application
shrinking	O
,	O
and	O
self-healing	O
.	O
</s>
<s>
NTFS	B-Application
symbolic	B-Application
links	I-Application
are	O
a	O
new	O
feature	O
in	O
the	O
file	O
system	O
;	O
all	O
the	O
others	O
are	O
new	O
operating	B-General_Concept
system	I-General_Concept
features	O
that	O
make	O
use	O
of	O
NTFS	B-Application
features	O
already	O
in	O
place	O
.	O
</s>
<s>
NTFS	B-Application
is	O
optimized	O
for	O
4KB	O
clusters	B-Application
,	O
but	O
supports	O
a	O
maximum	O
cluster	O
size	O
of	O
2MB	O
.	O
</s>
<s>
(	O
Earlier	O
implementations	O
support	O
up	O
to	O
64KB	O
)	O
The	O
maximum	O
NTFS	B-Application
volume	O
size	O
that	O
the	O
specification	O
can	O
support	O
is	O
clusters	B-Application
,	O
but	O
not	O
all	O
implementations	O
achieve	O
this	O
theoretical	O
maximum	O
,	O
as	O
discussed	O
below	O
.	O
</s>
<s>
The	O
maximum	O
NTFS	B-Application
volume	O
size	O
implemented	O
in	O
Windows	B-Application
XP	I-Application
Professional	O
is	O
clusters	B-Application
,	O
partly	O
due	O
to	O
partition	B-Application
table	O
limitations	O
.	O
</s>
<s>
For	O
example	O
,	O
using	O
64KB	O
clusters	B-Application
,	O
the	O
maximum	O
size	O
Windows	B-Application
XP	I-Application
NTFS	B-Application
volume	O
is	O
256TB	O
minus	O
64KB	O
.	O
</s>
<s>
Using	O
the	O
default	O
cluster	O
size	O
of	O
4KB	O
,	O
the	O
maximum	O
NTFS	B-Application
volume	O
size	O
is	O
16TB	O
minus	O
4KB	O
.	O
</s>
<s>
Both	O
of	O
these	O
are	O
vastly	O
higher	O
than	O
the	O
128GB	O
limit	O
in	O
Windows	B-Application
XP	I-Application
SP1	O
.	O
</s>
<s>
Because	O
partition	B-Application
tables	O
on	O
master	B-Device
boot	I-Device
record	I-Device
(	O
MBR	B-Device
)	O
disks	O
support	O
only	O
partition	B-Application
sizes	O
up	O
to	O
2TB	O
,	O
multiple	O
GUID	B-Application
Partition	I-Application
Table	I-Application
(	O
GPT	B-Application
or	O
"	O
dynamic	O
"	O
)	O
volumes	O
must	O
be	O
combined	O
to	O
create	O
a	O
single	O
NTFS	B-Application
volume	O
larger	O
than	O
2TB	O
.	O
</s>
<s>
Booting	O
from	O
a	O
GPT	B-Application
volume	O
to	O
a	O
Windows	O
environment	O
in	O
a	O
Microsoft	O
supported	O
way	O
requires	O
a	O
system	O
with	O
Unified	B-Architecture
Extensible	I-Architecture
Firmware	I-Architecture
Interface	I-Architecture
(	O
UEFI	B-Architecture
)	O
and	O
64-bit	O
support	O
.	O
</s>
<s>
The	O
NTFS	B-Application
maximum	O
theoretical	O
limit	O
on	O
the	O
size	O
of	O
individual	O
files	O
is	O
16EB	O
(	O
or	O
)	O
minus	O
1KB	O
,	O
which	O
totals	O
18,446,744,073,709,550,592	O
bytes	O
.	O
</s>
<s>
With	O
Windows	B-Operating_System
10	I-Operating_System
version	O
1709	O
and	O
Windows	B-Device
Server	I-Device
2019	I-Device
,	O
the	O
maximum	O
implemented	O
file	O
size	O
is	O
8PB	O
minus	O
2MB	O
or	O
9,007,199,252,643,840	O
bytes	O
.	O
</s>
<s>
While	O
the	O
different	O
NTFS	B-Application
versions	O
are	O
for	O
the	O
most	O
part	O
fully	O
forward	B-General_Concept
-	O
and	O
backward-compatible	B-General_Concept
,	O
there	O
are	O
technical	O
considerations	O
for	O
mounting	O
newer	O
NTFS	B-Application
volumes	O
in	O
older	O
versions	O
of	O
Microsoft	O
Windows	O
.	O
</s>
<s>
This	O
affects	O
dual-booting	B-Operating_System
,	O
and	O
external	O
portable	O
hard	B-Device
drives	I-Device
.	O
</s>
<s>
For	O
example	O
,	O
attempting	O
to	O
use	O
an	O
NTFS	B-Application
partition	B-Application
with	O
"	O
Previous	O
Versions	O
"	O
(	O
Volume	O
Shadow	O
Copy	O
)	O
on	O
an	O
operating	B-General_Concept
system	I-General_Concept
that	O
does	O
not	O
support	O
it	O
will	O
result	O
in	O
the	O
contents	O
of	O
those	O
previous	O
versions	O
being	O
lost	O
.	O
</s>
<s>
A	O
Windows	O
command-line	O
utility	O
called	O
convert.exe	B-Application
can	O
convert	B-Application
supporting	O
file	O
systems	O
to	O
NTFS	B-Application
,	O
including	O
HPFS	B-Application
(	O
only	O
on	O
Windows	B-Device
NT	I-Device
3.1	I-Device
,	O
3.5	O
,	O
and	O
3.51	O
)	O
,	O
FAT16	B-Application
and	O
FAT32	B-Application
(	O
on	O
Windows	B-Application
2000	I-Application
and	O
later	O
)	O
.	O
</s>
<s>
FreeBSD	B-Operating_System
3.2	O
released	O
in	O
May	O
1999	O
included	O
read-only	O
NTFS	B-Application
support	O
written	O
by	O
Semen	O
Ustimenko	O
.	O
</s>
<s>
This	O
implementation	O
was	O
ported	O
to	O
NetBSD	B-Device
by	O
Christos	O
Zoulas	O
and	O
Jaromir	O
Dolecek	O
and	O
released	O
with	O
NetBSD	B-Device
1.5	O
in	O
December	O
2000	O
.	O
</s>
<s>
The	O
FreeBSD	B-Operating_System
implementation	O
of	O
NTFS	B-Application
was	O
also	O
ported	O
to	O
OpenBSD	B-Operating_System
by	O
Julien	O
Bordet	O
and	O
offers	O
native	O
read-only	O
NTFS	B-Application
support	O
by	O
default	O
on	O
i386	O
and	O
amd64	O
platforms	O
as	O
of	O
version	O
4.9	O
released	O
1	O
May	O
2011	O
.	O
</s>
<s>
Linux	B-Operating_System
kernel	I-Operating_System
versions	O
2.1.74	O
and	O
later	O
include	O
a	O
driver	O
written	O
by	O
Martin	O
von	O
Löwis	O
which	O
has	O
the	O
ability	O
to	O
read	O
NTFS	B-Application
partitions	B-Application
;	O
kernel	B-Operating_System
versions	O
2.5.11	O
and	O
later	O
contain	O
a	O
new	O
driver	O
written	O
by	O
Anton	O
Altaparmakov	O
(	O
University	O
of	O
Cambridge	O
)	O
and	O
Richard	O
Russon	O
which	O
supports	O
file	O
read	O
.	O
</s>
<s>
The	O
ability	O
to	O
write	O
to	O
files	O
was	O
introduced	O
with	O
kernel	B-Operating_System
version	O
2.6.15	O
in	O
2006	O
which	O
allows	O
users	O
to	O
write	O
to	O
existing	O
files	O
but	O
does	O
not	O
allow	O
the	O
creation	O
of	O
new	O
ones	O
.	O
</s>
<s>
Paragon	O
's	O
NTFS	B-Application
driver	O
(	O
see	O
below	O
)	O
has	O
been	O
merged	O
into	O
kernel	B-Operating_System
version	O
5.15	O
,	O
and	O
it	O
supports	O
read/write	O
on	O
normal	O
,	O
compressed	B-General_Concept
and	O
sparse	B-General_Concept
files	I-General_Concept
,	O
as	O
well	O
as	O
journal	O
replaying	O
.	O
</s>
<s>
NTFS-3G	B-Application
is	O
a	O
free	O
GPL-licensed	O
FUSE	B-Application
implementation	O
of	O
NTFS	B-Application
that	O
was	O
initially	O
developed	O
as	O
a	O
Linux	B-Operating_System
kernel	I-Operating_System
driver	O
by	O
Szabolcs	O
Szakacsits	O
.	O
</s>
<s>
It	O
was	O
re-written	O
as	O
a	O
FUSE	B-Application
program	O
to	O
work	O
on	O
other	O
systems	O
that	O
FUSE	B-Application
supports	O
like	O
macOS	B-Application
,	O
FreeBSD	B-Operating_System
,	O
NetBSD	B-Device
,	O
OpenBSD	B-Operating_System
,	O
Solaris	B-Application
,	O
QNX	B-Operating_System
,	O
and	O
Haiku	B-Language
and	O
allows	O
reading	O
and	O
writing	O
to	O
NTFS	B-Application
partitions	B-Application
.	O
</s>
<s>
A	O
performance	O
enhanced	O
commercial	O
version	O
of	O
NTFS-3G	B-Application
,	O
called	O
"	O
Tuxera	O
NTFS	B-Application
for	O
Mac	O
"	O
,	O
is	O
also	O
available	O
from	O
the	O
NTFS-3G	B-Application
developers	O
.	O
</s>
<s>
Captive	B-Application
NTFS	I-Application
,	O
a	O
'	O
wrapping	O
 '	O
driver	O
that	O
uses	O
Windows	O
 '	O
own	O
driver	O
,	O
exists	O
for	O
Linux	B-Operating_System
.	O
</s>
<s>
It	O
was	O
built	O
as	O
a	O
Filesystem	B-Application
in	I-Application
Userspace	I-Application
(	O
FUSE	B-Application
)	O
program	O
and	O
released	O
under	O
the	O
GPL	B-License
but	O
work	O
on	O
Captive	B-Application
NTFS	I-Application
ceased	O
in	O
2006	O
.	O
</s>
<s>
Linux	B-Operating_System
kernel	I-Operating_System
versions	O
5.15	O
onwards	O
carry	O
NTFS3	O
,	O
a	O
fully	O
functional	O
NTFS	B-Application
Read-Write	O
driver	O
which	O
works	O
on	O
NTFS	B-Application
versions	O
up	O
to	O
3.1	O
and	O
is	O
maintained	O
primarily	O
by	O
the	O
Paragon	O
Software	O
Group	O
.	O
</s>
<s>
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.3	I-Operating_System
included	O
Ustimenko	O
's	O
read-only	O
implementation	O
of	O
NTFS	B-Application
from	O
FreeBSD	B-Operating_System
.	O
</s>
<s>
Then	O
in	O
2006	O
Apple	O
hired	O
Anton	O
Altaparmakov	O
to	O
write	O
a	O
new	O
NTFS	B-Application
implementation	O
for	O
Mac	B-Device
OS	I-Device
X	I-Device
10.6	I-Device
.	O
</s>
<s>
Native	O
NTFS	B-Application
write	O
support	O
is	O
included	O
in	O
10.6	B-Device
and	O
later	O
,	O
but	O
is	O
not	O
activated	O
by	O
default	O
,	O
although	O
workarounds	O
do	O
exist	O
to	O
enable	O
the	O
functionality	O
.	O
</s>
<s>
However	O
,	O
user	O
reports	O
indicate	O
the	O
functionality	O
is	O
unstable	O
and	O
tends	O
to	O
cause	O
kernel	B-Operating_System
panics	I-Operating_System
.	O
</s>
<s>
Paragon	O
Software	O
Group	O
sells	O
a	O
read-write	O
driver	O
named	O
NTFS	B-Application
for	O
Mac	B-Device
OS	I-Device
X	I-Device
,	O
which	O
is	O
also	O
included	O
on	O
some	O
models	O
of	O
Seagate	O
hard	B-Device
drives	I-Device
.	O
</s>
<s>
The	O
NetDrive	O
package	O
for	O
OS/2	B-Application
(	O
and	O
derivatives	O
such	O
as	O
eComStation	B-Device
and	O
ArcaOS	B-Device
)	O
supports	O
a	O
plugin	O
which	O
allows	O
read	O
and	O
write	O
access	O
to	O
NTFS	B-Application
volumes	O
.	O
</s>
<s>
There	O
is	O
a	O
free-for-personal-use	O
read/write	O
driver	O
for	O
MS-DOS	B-Application
by	O
Avira	B-Application
called	O
"	O
NTFS4DOS	B-Application
"	O
.	O
</s>
<s>
Ahead	O
Software	O
developed	O
a	O
"	O
NTFSREAD	B-Application
"	O
driver	O
(	O
version	O
1.200	O
)	O
for	O
DR-DOS	B-Application
7.0x	O
between	O
2002	O
and	O
2004	O
.	O
</s>
<s>
It	O
was	O
part	O
of	O
their	O
Nero	B-Application
Burning	I-Application
ROM	I-Application
software	O
.	O
</s>
<s>
NTFS	B-Application
uses	O
access	O
control	O
lists	O
and	O
user-level	O
encryption	O
to	O
help	O
secure	O
user	O
data	O
.	O
</s>
<s>
In	O
NTFS	B-Application
,	O
each	O
file	O
or	O
folder	O
is	O
assigned	O
a	O
security	O
descriptor	O
that	O
defines	O
its	O
owner	O
and	O
contains	O
two	O
access	O
control	O
lists	O
(	O
ACLs	O
)	O
.	O
</s>
<s>
Windows	B-Application
Vista	I-Application
adds	O
mandatory	O
access	O
control	O
info	O
to	O
DACLs	O
.	O
</s>
<s>
DACLs	O
are	O
the	O
primary	O
focus	O
of	O
User	O
Account	O
Control	O
in	O
Windows	B-Application
Vista	I-Application
and	O
later	O
.	O
</s>
<s>
Encrypting	O
File	O
System	O
(	O
EFS	O
)	O
provides	O
user-transparent	O
encryption	O
of	O
any	O
file	O
or	O
folder	O
on	O
an	O
NTFS	B-Application
volume	O
.	O
</s>
<s>
EFS	O
works	O
by	O
encrypting	O
a	O
file	O
with	O
a	O
bulk	O
symmetric	B-Algorithm
key	I-Algorithm
(	O
also	O
known	O
as	O
the	O
File	O
Encryption	O
Key	O
,	O
or	O
FEK	O
)	O
,	O
which	O
is	O
used	O
because	O
it	O
takes	O
a	O
relatively	O
small	O
amount	O
of	O
time	O
to	O
encrypt	O
and	O
decrypt	O
large	O
amounts	O
of	O
data	O
than	O
if	O
an	O
asymmetric	B-Application
key	I-Application
cipher	O
is	O
used	O
.	O
</s>
<s>
The	O
symmetric	B-Algorithm
key	I-Algorithm
that	O
is	O
used	O
to	O
encrypt	O
the	O
file	O
is	O
then	O
encrypted	O
with	O
a	O
public	B-Application
key	I-Application
that	O
is	O
associated	O
with	O
the	O
user	O
who	O
encrypted	O
the	O
file	O
,	O
and	O
this	O
encrypted	O
data	O
is	O
stored	O
in	O
an	O
alternate	O
data	O
stream	O
of	O
the	O
encrypted	O
file	O
.	O
</s>
<s>
To	O
decrypt	O
the	O
file	O
,	O
the	O
file	O
system	O
uses	O
the	O
private	B-Application
key	I-Application
of	O
the	O
user	O
to	O
decrypt	O
the	O
symmetric	B-Algorithm
key	I-Algorithm
that	O
is	O
stored	O
in	O
the	O
data	O
stream	O
.	O
</s>
<s>
It	O
then	O
uses	O
the	O
symmetric	B-Algorithm
key	I-Algorithm
to	O
decrypt	O
the	O
file	O
.	O
</s>
<s>
NTFS-provided	O
encryption	O
and	O
NTFS-provided	O
compression	O
are	O
mutually	O
exclusive	O
;	O
however	O
,	O
NTFS	B-Application
can	O
be	O
used	O
for	O
one	O
and	O
a	O
third-party	O
tool	O
for	O
the	O
other	O
.	O
</s>
<s>
NTFS	B-Application
is	O
a	O
journaling	B-Application
file	I-Application
system	I-Application
and	O
uses	O
the	O
NTFS	B-Application
Log	O
(	O
)	O
to	O
record	O
metadata	O
changes	O
to	O
the	O
volume	O
.	O
</s>
<s>
It	O
is	O
a	O
feature	O
that	O
FAT	B-Application
does	O
not	O
provide	O
and	O
critical	O
for	O
NTFS	B-Application
to	O
ensure	O
that	O
its	O
complex	O
internal	O
data	O
structures	O
will	O
remain	O
consistent	O
in	O
case	O
of	O
system	O
crashes	O
or	O
data	O
moves	O
performed	O
by	O
the	O
defragmentation	B-Application
API	O
,	O
and	O
allow	O
easy	O
rollback	O
of	O
uncommitted	O
changes	O
to	O
these	O
critical	O
data	O
structures	O
when	O
the	O
volume	O
is	O
remounted	O
.	O
</s>
<s>
The	O
incompatibility	O
of	O
the	O
versions	O
implemented	O
by	O
Windows	B-Application
8	I-Application
,	O
Windows	B-Operating_System
10	I-Operating_System
,	O
Windows	B-Application
11	I-Application
prevents	O
Windows	B-Device
7	I-Device
(	O
and	O
earlier	O
versions	O
of	O
Windows	O
)	O
from	O
recognizing	O
version	O
2.0	O
of	O
the	O
.	O
</s>
<s>
Backward	B-General_Concept
compatibility	I-General_Concept
is	O
provided	O
by	O
downgrading	O
the	O
to	O
version	O
1.1	O
when	O
an	O
NTFS	B-Application
volume	O
is	O
cleanly	O
dismounted	O
.	O
</s>
<s>
The	O
inability	O
to	O
process	O
version	O
2.0	O
of	O
the	O
by	O
versions	O
of	O
Windows	O
older	O
than	O
8.0	O
results	O
in	O
an	O
unnecessary	O
invocation	O
of	O
the	O
CHKDSK	B-Device
disk	O
repair	O
utility	O
.	O
</s>
<s>
This	O
is	O
particularly	O
a	O
concern	O
in	O
a	O
multi-boot	B-Operating_System
scenario	O
involving	O
pre	O
-	O
and	O
post-8.0	O
versions	O
of	O
Windows	O
,	O
or	O
when	O
frequently	O
moving	O
a	O
storage	O
device	O
between	O
older	O
and	O
newer	O
versions	O
.	O
</s>
<s>
A	O
Windows	B-Protocol
Registry	I-Protocol
setting	O
exists	O
to	O
prevent	O
the	O
automatic	O
upgrade	O
of	O
the	O
to	O
the	O
newer	O
version	O
.	O
</s>
<s>
The	O
USN	B-Application
Journal	I-Application
(	O
Update	O
Sequence	O
Number	O
Journal	O
)	O
is	O
a	O
system	O
management	O
feature	O
that	O
records	O
(	O
in	O
)	O
changes	O
to	O
files	O
,	O
streams	O
and	O
directories	O
on	O
the	O
volume	O
,	O
as	O
well	O
as	O
their	O
various	O
attributes	O
and	O
security	O
settings	O
.	O
</s>
<s>
The	O
hard	B-Application
link	I-Application
feature	O
allows	O
different	O
file	O
names	O
to	O
directly	O
refer	O
to	O
the	O
same	O
file	O
contents	O
.	O
</s>
<s>
Hard	B-Application
links	I-Application
may	O
link	O
only	O
to	O
files	O
in	O
the	O
same	O
volume	O
,	O
because	O
each	O
volume	O
has	O
its	O
own	O
MFT	O
.	O
</s>
<s>
Hard	B-Application
links	I-Application
were	O
originally	O
included	O
to	O
support	O
the	O
POSIX	O
subsystem	O
in	O
Windows	B-Device
NT	I-Device
.	O
</s>
<s>
Although	O
Hard	B-Application
links	I-Application
use	O
the	O
same	O
MFT	O
record	O
(	O
inode	B-Application
)	O
which	O
records	O
file	O
metadata	O
such	O
as	O
file	O
size	O
,	O
modification	O
date	O
,	O
and	O
attributes	O
,	O
NTFS	B-Application
also	O
caches	O
this	O
data	O
in	O
the	O
directory	O
entry	O
as	O
a	O
performance	O
enhancement	O
.	O
</s>
<s>
This	O
means	O
that	O
when	O
listing	O
the	O
contents	O
of	O
a	O
directory	O
using	O
FindFirstFile/FindNextFile	O
family	O
of	O
APIs	O
,	O
(	O
equivalent	O
to	O
the	O
POSIX	O
opendir/readdir	O
APIs	O
)	O
you	O
will	O
also	O
receive	O
this	O
cached	O
information	O
,	O
in	O
addition	O
to	O
the	O
name	O
and	O
inode	B-Application
.	O
</s>
<s>
This	O
means	O
where	O
a	O
file	O
has	O
multiple	O
names	O
via	O
hard	B-Application
links	I-Application
,	O
updating	O
a	O
file	O
via	O
one	O
name	O
does	O
not	O
update	O
the	O
cached	O
data	O
associated	O
with	O
the	O
other	O
name	O
.	O
</s>
<s>
Windows	O
uses	O
hard	B-Application
links	I-Application
to	O
support	O
short	O
(	O
8.3	O
)	O
filenames	O
in	O
NTFS	B-Application
.	O
</s>
<s>
Operating	B-General_Concept
system	I-General_Concept
support	O
is	O
needed	O
because	O
there	O
are	O
legacy	O
applications	O
that	O
can	O
work	O
only	O
with	O
8.3	O
filenames	O
,	O
but	O
support	O
can	O
be	O
disabled	O
.	O
</s>
<s>
In	O
this	O
case	O
,	O
an	O
additional	O
filename	O
record	O
and	O
directory	O
entry	O
is	O
added	O
,	O
but	O
both	O
8.3	O
and	O
long	O
file	O
name	O
are	O
linked	O
and	O
updated	O
together	O
,	O
unlike	O
a	O
regular	O
hard	B-Application
link	I-Application
.	O
</s>
<s>
The	O
NTFS	B-Application
file	I-Application
system	I-Application
has	O
a	O
limit	O
of	O
1024	O
hard	B-Application
links	I-Application
on	O
a	O
file	O
.	O
</s>
<s>
Alternate	O
data	O
streams	O
allow	O
more	O
than	O
one	O
data	O
stream	O
to	O
be	O
associated	O
with	O
a	O
filename	O
(	O
a	O
fork	B-Application
)	O
,	O
using	O
the	O
format	O
"	O
filename:streamname	O
"	O
(	O
e.g.	O
,	O
"	O
text.txt:extrastream	O
"	O
)	O
.	O
</s>
<s>
NTFS	B-Application
Streams	O
were	O
introduced	O
in	O
Windows	B-Device
NT	I-Device
3.1	I-Device
,	O
to	O
enable	O
Services	O
for	O
Macintosh	O
(	O
SFM	O
)	O
to	O
store	O
resource	B-Operating_System
forks	I-Operating_System
.	O
</s>
<s>
Although	O
current	O
versions	O
of	O
Windows	B-Device
Server	I-Device
no	O
longer	O
include	O
SFM	O
,	O
third-party	O
Apple	B-Protocol
Filing	I-Protocol
Protocol	I-Protocol
(	O
AFP	O
)	O
products	O
(	O
such	O
as	O
GroupLogic	B-Protocol
's	O
ExtremeZ-IP	B-General_Concept
)	O
still	O
use	O
this	O
feature	O
of	O
the	O
file	O
system	O
.	O
</s>
<s>
Very	O
small	O
ADSs	O
(	O
named	O
"	O
Zone.Identifier	O
"	O
)	O
are	O
added	O
by	O
Internet	B-Application
Explorer	I-Application
and	O
recently	O
by	O
other	O
browsers	O
to	O
mark	O
files	O
downloaded	O
from	O
external	O
sites	O
as	O
possibly	O
unsafe	O
to	O
run	O
;	O
the	O
local	O
shell	O
would	O
then	O
require	O
user	O
confirmation	O
before	O
opening	O
them	O
.	O
</s>
<s>
Starting	O
with	O
Windows	B-Application
PowerShell	I-Application
3.0	O
,	O
it	O
is	O
possible	O
to	O
manage	O
ADS	O
natively	O
with	O
six	O
cmdlets	O
:	O
Add-Content	O
,	O
Clear-Content	O
,	O
Get-Content	O
,	O
Get-Item	O
,	O
Remove-Item	O
,	O
Set-Content	O
.	O
</s>
<s>
Compression	O
is	O
enabled	O
on	O
a	O
per-folder	O
or	O
per-file	O
basis	O
by	O
setting	O
the	O
'	O
compressed	B-General_Concept
 '	O
attribute	O
.	O
</s>
<s>
When	O
compression	O
is	O
enabled	O
on	O
a	O
folder	O
,	O
any	O
files	O
moved	O
or	O
saved	O
to	O
that	O
folder	O
will	O
be	O
automatically	O
compressed	B-General_Concept
using	O
LZNT1	O
algorithm	O
(	O
a	O
variant	O
of	O
LZ77	O
)	O
.	O
</s>
<s>
The	O
compression	B-General_Concept
algorithm	I-General_Concept
is	O
designed	O
to	O
support	O
cluster	O
sizes	O
of	O
up	O
to	O
4KB	O
;	O
when	O
the	O
cluster	O
size	O
is	O
greater	O
than	O
4KB	O
on	O
an	O
NTFS	B-Application
volume	O
,	O
NTFS	B-Application
compression	O
is	O
not	O
available	O
.	O
</s>
<s>
Data	O
is	O
compressed	B-General_Concept
in	O
16-cluster	O
chunks	O
(	O
up	O
to	O
64KB	O
in	O
size	O
)	O
;	O
if	O
the	O
compression	O
reduces	O
64KB	O
of	O
data	O
to	O
60KB	O
or	O
less	O
,	O
NTFS	B-Application
treats	O
the	O
unneeded	O
4KB	O
pages	O
like	O
empty	O
sparse	B-General_Concept
file	I-General_Concept
clusters	B-Application
—	O
they	O
are	O
not	O
written	O
.	O
</s>
<s>
Compression	O
works	O
best	O
with	O
files	O
that	O
have	O
repetitive	O
content	O
,	O
are	O
seldom	O
written	O
,	O
are	O
usually	O
accessed	O
sequentially	O
,	O
and	O
are	O
not	O
themselves	O
compressed	B-General_Concept
.	O
</s>
<s>
Single-user	O
systems	O
with	O
limited	O
hard	B-Device
disk	I-Device
space	O
can	O
benefit	O
from	O
NTFS	B-Application
compression	O
for	O
small	O
files	O
,	O
from	O
4KB	O
to	O
64KB	O
or	O
more	O
,	O
depending	O
on	O
compressibility	O
.	O
</s>
<s>
Users	O
of	O
fast	O
multi-core	B-Architecture
processors	I-Architecture
will	O
find	O
improvements	O
in	O
application	O
speed	O
by	O
compressing	O
their	O
applications	O
and	O
data	O
as	O
well	O
as	O
a	O
reduction	O
in	O
space	O
used	O
.	O
</s>
<s>
Even	O
when	O
SSD	B-Device
controllers	O
already	O
compress	O
data	O
,	O
there	O
is	O
still	O
a	O
reduction	O
in	O
I/Os	O
since	O
less	O
data	O
is	O
transferred	O
.	O
</s>
<s>
According	O
to	O
research	O
by	O
Microsoft	O
's	O
NTFS	B-Application
Development	O
team	O
,	O
50	O
–	O
60GB	O
is	O
a	O
reasonable	O
maximum	O
size	O
for	O
a	O
compressed	B-General_Concept
file	O
on	O
an	O
NTFS	B-Application
volume	O
with	O
a	O
4KB	O
(	O
default	O
)	O
cluster	O
(	O
block	O
)	O
size	O
.	O
</s>
<s>
Flash	O
memory	O
,	O
such	O
as	O
SSD	B-Device
drives	I-Device
do	O
not	O
have	O
the	O
head	O
movement	O
delays	O
and	O
high	O
access	O
time	O
of	O
mechanical	O
hard	B-Device
disk	I-Device
drives	I-Device
,	O
so	O
fragmentation	B-Application
has	O
only	O
a	O
smaller	O
penalty	O
.	O
</s>
<s>
If	O
system	O
files	O
that	O
are	O
needed	O
at	O
boot	O
time	O
(	O
such	O
as	O
drivers	O
,	O
NTLDR	B-Application
,	O
winload.exe	O
,	O
or	O
BOOTMGR	O
)	O
are	O
compressed	B-General_Concept
,	O
the	O
system	O
may	O
fail	O
to	O
boot	O
correctly	O
,	O
because	O
decompression	O
filters	O
are	O
not	O
yet	O
loaded	O
.	O
</s>
<s>
Later	O
editions	O
of	O
Windows	O
do	O
not	O
allow	O
important	O
system	O
files	O
to	O
be	O
compressed	B-General_Concept
.	O
</s>
<s>
Since	O
Windows	B-Operating_System
10	I-Operating_System
,	O
Microsoft	O
has	O
introduced	O
new	O
file	B-General_Concept
compression	I-General_Concept
scheme	O
based	O
on	O
the	O
XPRESS	O
algorithm	O
with	O
4K/8K/16K	O
block	O
size	O
and	O
the	O
LZX	B-Device
algorithm	O
;	O
both	O
are	O
variants	O
of	O
LZ77	O
updated	O
with	O
Huffman	B-General_Concept
entropy	I-General_Concept
coding	I-General_Concept
and	O
range	B-Algorithm
coding	I-Algorithm
,	O
which	O
LZNT1	O
lacked	O
.	O
</s>
<s>
These	O
compression	B-General_Concept
algorithms	I-General_Concept
were	O
taken	O
from	O
Windows	O
Imaging	O
Format	O
(	O
WIM	O
file	O
)	O
.	O
</s>
<s>
CompactOS	O
is	O
not	O
an	O
extension	O
of	O
NTFS	B-Application
file	B-General_Concept
compression	I-General_Concept
and	O
does	O
not	O
use	O
the	O
'	O
compressed	B-General_Concept
 '	O
attribute	O
;	O
instead	O
,	O
it	O
sets	O
a	O
reparse	B-Application
point	I-Application
on	O
each	O
compressed	B-General_Concept
file	O
with	O
a	O
WOF	O
(	O
Windows	O
Overlay	O
Filter	O
)	O
tag	O
,	O
but	O
the	O
actual	O
data	O
is	O
stored	O
in	O
an	O
alternate	O
data	O
stream	O
named	O
"	O
WofCompressedData	O
"	O
,	O
which	O
is	O
decompressed	O
on-the-fly	O
by	O
a	O
WOF	O
filesystem	B-Application
filter	I-Application
driver	O
,	O
and	O
the	O
main	O
file	O
is	O
an	O
empty	O
sparse	B-General_Concept
file	I-General_Concept
.	O
</s>
<s>
This	O
design	O
is	O
meant	O
purely	O
for	O
read-only	O
access	O
,	O
so	O
any	O
writes	O
to	O
compressed	B-General_Concept
files	O
result	O
in	O
an	O
automatic	O
decompression	O
.	O
</s>
<s>
CompactOS	O
algorithm	O
avoids	O
file	B-Application
fragmentation	I-Application
by	O
writing	O
compressed	B-General_Concept
data	I-General_Concept
in	O
contiguously	O
allocated	O
chunks	O
,	O
unlike	O
core	O
NTFS	B-Application
compression	O
.	O
</s>
<s>
CompactOS	O
file	B-General_Concept
compression	I-General_Concept
is	O
an	O
improved	O
version	O
of	O
WIMBoot	O
feature	O
introduced	O
in	O
Windows	B-Device
8.1	I-Device
.	O
</s>
<s>
WIMBoot	O
reduces	O
Windows	O
disk	O
usage	O
by	O
keeping	O
system	O
files	O
in	O
a	O
compressed	B-General_Concept
WIM	O
image	O
on	O
a	O
separate	O
hidden	O
disk	B-Application
partition	I-Application
.	O
</s>
<s>
Similarly	O
to	O
CompactOS	O
,	O
Windows	O
system	O
directories	O
only	O
contain	O
sparse	B-General_Concept
files	I-General_Concept
marked	O
by	O
a	O
reparse	B-Application
point	I-Application
with	O
a	O
WOF	O
tag	O
,	O
and	O
Windows	O
Overlay	O
Filter	O
driver	O
decompresses	O
file	O
contents	O
on-the-fly	O
from	O
the	O
WIM	O
image	O
.	O
</s>
<s>
WIMBoot	O
is	O
less	O
effective	O
than	O
CompactOS	O
though	O
,	O
as	O
new	O
updated	O
versions	O
of	O
system	O
files	O
need	O
to	O
be	O
written	O
to	O
the	O
system	O
partition	B-Application
,	O
consuming	O
disk	O
space	O
.	O
</s>
<s>
Sparse	B-General_Concept
files	I-General_Concept
are	O
files	O
interspersed	O
with	O
empty	O
segments	O
for	O
which	O
no	O
actual	O
storage	O
space	O
is	O
used	O
.	O
</s>
<s>
To	O
the	O
applications	O
,	O
the	O
file	O
looks	O
like	O
an	O
ordinary	O
file	O
with	O
empty	O
regions	O
seen	O
as	O
regions	O
filled	O
with	O
zeros	O
;	O
the	O
file	O
system	O
maintains	O
an	O
internal	O
list	O
of	O
such	O
regions	O
for	O
each	O
sparse	B-General_Concept
file	I-General_Concept
.	O
</s>
<s>
A	O
sparse	B-General_Concept
file	I-General_Concept
does	O
not	O
necessarily	O
include	O
sparse	O
zeros	O
areas	O
;	O
the	O
"	O
sparse	B-General_Concept
file	I-General_Concept
"	O
attribute	O
just	O
means	O
that	O
the	O
file	O
is	O
allowed	O
to	O
have	O
them	O
.	O
</s>
<s>
Database	O
applications	O
,	O
for	O
instance	O
,	O
may	O
use	O
sparse	B-General_Concept
files	I-General_Concept
.	O
</s>
<s>
As	O
with	O
compressed	B-General_Concept
files	O
,	O
the	O
actual	O
sizes	O
of	O
sparse	B-General_Concept
files	I-General_Concept
are	O
not	O
taken	O
into	O
account	O
when	O
determining	O
quota	B-Application
limits	O
.	O
</s>
<s>
The	O
Volume	O
Shadow	O
Copy	O
Service	O
(	O
VSS	O
)	O
keeps	O
historical	O
versions	O
of	O
files	O
and	O
folders	O
on	O
NTFS	B-Application
volumes	O
by	O
copying	O
old	O
,	O
newly	O
overwritten	O
data	O
to	O
shadow	O
copy	O
via	O
copy-on-write	B-Language
technique	O
.	O
</s>
<s>
Windows	B-Application
Vista	I-Application
also	O
introduced	O
persistent	O
shadow	O
copies	O
for	O
use	O
with	O
System	O
Restore	O
and	O
Previous	O
Versions	O
features	O
.	O
</s>
<s>
Persistent	O
shadow	O
copies	O
,	O
however	O
,	O
are	O
deleted	O
when	O
an	O
older	O
operating	B-General_Concept
system	I-General_Concept
mounts	O
that	O
NTFS	B-Application
volume	O
.	O
</s>
<s>
This	O
happens	O
because	O
the	O
older	O
operating	B-General_Concept
system	I-General_Concept
does	O
not	O
understand	O
the	O
newer	O
format	O
of	O
persistent	O
shadow	O
copies	O
.	O
</s>
<s>
As	O
of	O
Windows	B-Application
Vista	I-Application
,	O
applications	O
can	O
use	O
Transactional	O
NTFS	B-Application
(	O
TxF	O
)	O
to	O
group	O
multiple	O
changes	O
to	O
files	O
together	O
into	O
a	O
single	O
transaction	O
.	O
</s>
<s>
copy-on-write	B-Language
)	O
to	O
ensure	O
that	O
overwritten	O
data	O
can	O
be	O
safely	O
rolled	O
back	O
,	O
and	O
a	O
CLFS	O
log	O
to	O
mark	O
the	O
transactions	O
that	O
have	O
still	O
not	O
been	O
committed	O
,	O
or	O
those	O
that	O
have	O
been	O
committed	O
but	O
still	O
not	O
fully	O
applied	O
(	O
in	O
case	O
of	O
system	O
crash	O
during	O
a	O
commit	O
by	O
one	O
of	O
the	O
participants	O
)	O
.	O
</s>
<s>
Transactional	O
NTFS	B-Application
does	O
not	O
restrict	O
transactions	O
to	O
just	O
the	O
local	O
NTFS	B-Application
volume	O
,	O
but	O
also	O
includes	O
other	O
transactional	O
data	O
or	O
operations	O
in	O
other	O
locations	O
such	O
as	O
data	O
stored	O
in	O
separate	O
volumes	O
,	O
the	O
local	O
registry	O
,	O
or	O
SQL	O
databases	O
,	O
or	O
the	O
current	O
states	O
of	O
system	O
services	O
or	O
remote	O
services	O
.	O
</s>
<s>
Transactional	O
NTFS	B-Application
allows	O
,	O
for	O
example	O
,	O
the	O
creation	O
of	O
network-wide	O
consistent	O
distributed	O
file	O
systems	O
,	O
including	O
with	O
their	O
local	O
live	O
or	O
offline	O
caches	O
.	O
</s>
<s>
Disk	B-Application
quotas	I-Application
were	O
introduced	O
in	O
NTFS	B-Application
v3	O
.	O
</s>
<s>
They	O
allow	O
the	O
administrator	O
of	O
a	O
computer	O
that	O
runs	O
a	O
version	O
of	O
Windows	O
that	O
supports	O
NTFS	B-Application
to	O
set	O
a	O
threshold	O
of	O
disk	O
space	O
that	O
users	O
may	O
use	O
.	O
</s>
<s>
Disk	B-Application
quotas	I-Application
do	O
not	O
take	O
into	O
account	O
NTFS	B-Application
's	O
transparent	O
file-compression	B-General_Concept
,	O
should	O
this	O
be	O
enabled	O
.	O
</s>
<s>
Applications	O
that	O
query	O
the	O
amount	O
of	O
free	O
space	O
will	O
also	O
see	O
the	O
amount	O
of	O
free	O
space	O
left	O
to	O
the	O
user	O
who	O
has	O
a	O
quota	B-Application
applied	O
to	O
them	O
.	O
</s>
<s>
Introduced	O
in	O
NTFS	B-Application
v3	O
,	O
NTFS	B-Application
reparse	I-Application
points	I-Application
are	O
used	O
by	O
associating	O
a	O
reparse	O
tag	O
in	O
the	O
user	O
space	O
attribute	O
of	O
a	O
file	O
or	O
directory	O
.	O
</s>
<s>
Microsoft	O
includes	O
several	O
default	O
tags	O
including	O
symbolic	B-Application
links	I-Application
,	O
directory	O
junction	O
points	O
and	O
volume	O
mount	O
points	O
.	O
</s>
<s>
Each	O
filter	O
driver	O
examines	O
the	O
reparse	O
data	O
to	O
see	O
whether	O
it	O
is	O
associated	O
with	O
that	O
reparse	B-Application
point	I-Application
,	O
and	O
if	O
that	O
filter	O
driver	O
determines	O
a	O
match	O
,	O
then	O
it	O
intercepts	O
the	O
file	O
system	O
request	O
and	O
performs	O
its	O
special	O
functionality	O
.	O
</s>
<s>
Starting	O
with	O
Windows	B-Application
Vista	I-Application
Microsoft	O
added	O
the	O
built-in	O
ability	O
to	O
shrink	O
or	O
expand	O
a	O
partition	B-Application
.	O
</s>
<s>
However	O
,	O
this	O
ability	O
does	O
not	O
relocate	O
page	O
file	O
fragments	O
or	O
files	O
that	O
have	O
been	O
marked	O
as	O
unmovable	O
,	O
so	O
shrinking	O
a	O
volume	O
will	O
often	O
require	O
relocating	O
or	O
disabling	O
any	O
page	O
file	O
,	O
the	O
index	O
of	O
Windows	B-Application
Search	I-Application
,	O
and	O
any	O
Shadow	O
Copy	O
used	O
by	O
System	O
Restore	O
.	O
</s>
<s>
Various	O
third-party	O
tools	O
are	O
capable	O
of	O
resizing	O
NTFS	B-Application
partitions	B-Application
.	O
</s>
<s>
Since	O
2017	O
,	O
Microsoft	O
requires	O
the	O
OneDrive	O
file	O
structure	O
to	O
reside	O
on	O
an	O
NTFS	B-Application
disk	O
.	O
</s>
<s>
This	O
is	O
because	O
OneDrive	O
Files	O
On-Demand	O
feature	O
uses	O
NTFS	B-Application
reparse	I-Application
points	I-Application
to	O
link	O
files	O
and	O
folders	O
that	O
are	O
stored	O
in	O
OneDrive	O
to	O
the	O
local	O
filesystem	O
,	O
making	O
the	O
file	O
or	O
folder	O
unusable	O
with	O
any	O
previous	O
version	O
of	O
Windows	O
,	O
with	O
any	O
other	O
NTFS	B-Application
file	I-Application
system	I-Application
driver	O
,	O
or	O
any	O
file	O
system	O
and	O
backup	O
utilities	O
not	O
updated	O
to	O
support	O
it	O
.	O
</s>
<s>
NTFS	B-Application
is	O
made	O
up	O
of	O
several	O
components	O
including	O
:	O
a	O
partition	B-Device
boot	I-Device
sector	I-Device
(	O
PBS	O
)	O
that	O
holds	O
boot	O
information	O
;	O
the	O
master	O
file	O
table	O
that	O
stores	O
a	O
record	O
of	O
all	O
files	O
and	O
folders	O
in	O
the	O
filesystem	O
;	O
a	O
series	O
of	O
meta	O
files	O
that	O
help	O
structure	O
meta	O
data	O
more	O
efficiently	O
;	O
data	O
streams	O
and	O
locking	O
mechanisms	O
.	O
</s>
<s>
Internally	O
,	O
NTFS	B-Application
uses	O
B-trees	B-Architecture
to	O
index	O
file	O
system	O
data	O
.	O
</s>
<s>
A	O
file	B-Application
system	I-Application
journal	I-Application
is	O
used	O
to	O
guarantee	O
the	O
integrity	O
of	O
the	O
file	O
system	O
metadata	O
but	O
not	O
individual	O
files	O
 '	O
content	O
.	O
</s>
<s>
Systems	O
using	O
NTFS	B-Application
are	O
known	O
to	O
have	O
improved	O
reliability	O
compared	O
to	O
FAT	B-Application
file	I-Application
systems	I-Application
.	O
</s>
<s>
NTFS	B-Application
allows	O
any	O
sequence	O
of	O
16-bit	O
values	O
for	O
name	O
encoding	O
(	O
e.g.	O
</s>
<s>
In	O
Win32	B-Library
namespace	O
,	O
any	O
UTF-16	O
code	O
units	O
are	O
case	O
insensitive	O
whereas	O
in	O
POSIX	O
namespace	O
they	O
are	O
case	O
sensitive	O
.	O
</s>
<s>
Certain	O
names	O
are	O
reserved	O
in	O
the	O
volume	O
root	B-Application
directory	I-Application
and	O
cannot	O
be	O
used	O
for	O
files	O
.	O
</s>
<s>
The	O
NT	O
kernel	B-Operating_System
limits	O
full	O
paths	O
to	O
32,767	O
UTF-16	O
code	O
units	O
.	O
</s>
<s>
+	O
NTFS	B-Application
boot	O
sector	O
contents	O
(	O
All	O
values	O
except	O
strings	O
are	O
stored	O
in	O
little	O
endian	O
order	O
.	O
)	O
</s>
<s>
Byte	O
offset	O
Field	O
length	O
Typical	O
valueField	O
name	O
Purpose	O
0x00	O
3	O
bytes	O
0xEB5290x86	O
JMP	B-Device
and	O
NOP	O
instructions	O
Causes	O
execution	O
to	O
continue	O
after	O
the	O
data	O
structures	O
in	O
this	O
boot	O
sector	O
.	O
</s>
<s>
0x03	O
8	O
bytes	O
"	O
NTFS	B-Application
"	O
Word	O
"	O
NTFS	B-Application
"	O
followed	O
by	O
four	O
trailing	O
spaces	O
(	O
0x20	O
)	O
OEM	O
ID	O
This	O
is	O
the	O
magic	O
number	O
that	O
indicates	O
this	O
is	O
an	O
NTFS	B-Application
file	I-Application
system	I-Application
.	O
</s>
<s>
0x0E	O
2	O
bytes	O
0x0000	O
Reserved	O
Sectors	O
,	O
unused	O
0x10	O
3	O
bytes	O
0x000000	O
Unused	O
This	O
field	O
is	O
always	O
0	O
0x13	O
2	O
bytes	O
0x0000	O
Unused	O
by	O
NTFS	B-Application
This	O
field	O
is	O
always	O
0	O
0x15	O
1	O
byte	O
0xF8	O
Media	O
Descriptor	O
The	O
type	O
of	O
drive	O
.	O
</s>
<s>
0xF8	O
is	O
used	O
to	O
denote	O
a	O
hard	B-Device
drive	I-Device
(	O
in	O
contrast	O
to	O
the	O
several	O
sizes	O
of	O
floppy	O
)	O
.	O
</s>
<s>
0x1C	O
4	O
bytes	O
0x0000003F	O
Hidden	O
Sectors	O
The	O
number	O
of	O
sectors	O
preceding	O
the	O
partition	B-Application
.	O
</s>
<s>
0x20	O
4	O
bytes	O
0x00000000	O
Unused	O
Not	O
used	O
by	O
NTFS	B-Application
0x24	O
4	O
bytes	O
0x00800080	O
EBPB	B-Device
Unused	O
Not	O
used	O
by	O
NTFS	B-Application
0x28	O
8	O
bytes	O
0x00000000007FF54A	O
Total	O
sectors	O
The	O
partition	B-Application
size	O
in	O
sectors	O
.	O
</s>
<s>
0x30	O
8	O
bytes	O
0x0000000000000004	O
$MFT	O
cluster	O
number	O
The	O
cluster	O
that	O
contains	O
the	O
Master	O
File	O
Table	O
0x38	O
8	O
bytes	O
0x000000000007FF54	O
$MFTMirr	O
cluster	O
number	O
The	O
cluster	O
that	O
contains	O
a	O
backup	O
of	O
the	O
Master	O
File	O
Table	O
0x40	O
1	O
byte	O
0xF6	O
Bytes	O
or	O
Clusters	B-Application
Per	O
File	O
Record	O
Segment	O
A	O
positive	O
value	O
denotes	O
the	O
number	O
of	O
clusters	B-Application
in	O
a	O
File	O
Record	O
Segment	O
.	O
</s>
<s>
0x41	O
3	O
bytes	O
0x000000	O
Unused	O
This	O
field	O
is	O
not	O
used	O
by	O
NTFS	B-Application
0x44	O
1	O
byte	O
0x01	O
Bytes	O
or	O
Clusters	B-Application
Per	O
Index	O
Buffer	O
A	O
positive	O
value	O
denotes	O
the	O
number	O
of	O
clusters	B-Application
in	O
an	O
Index	O
Buffer	O
.	O
</s>
<s>
A	O
negative	O
value	O
denotes	O
the	O
amount	O
of	O
bytes	O
and	O
it	O
uses	O
the	O
same	O
algorithm	O
for	O
negative	O
numbers	O
as	O
the	O
"	O
Bytes	O
or	O
Clusters	B-Application
Per	O
File	O
Record	O
Segment.	O
"	O
</s>
<s>
0x45	O
3	O
bytes	O
0x000000	O
Unused	O
This	O
field	O
is	O
not	O
used	O
by	O
NTFS	B-Application
0x48	O
8	O
bytes	O
0x1C741BC9741BA514	O
Volume	B-Application
Serial	I-Application
Number	I-Application
A	O
unique	O
random	O
number	O
assigned	O
to	O
this	O
partition	B-Application
,	O
to	O
keep	O
things	O
organized	O
.	O
</s>
<s>
0x54	O
426	O
bytesBootstrap	O
Code	O
The	O
code	O
that	O
loads	O
the	O
rest	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
This	O
boot	O
partition	B-Application
format	O
is	O
roughly	O
based	O
upon	O
the	O
earlier	O
FAT	B-Application
filesystem	I-Application
,	O
but	O
the	O
fields	O
are	O
in	O
different	O
locations	O
.	O
</s>
<s>
This	O
value	O
is	O
the	O
sector	O
offset	O
(	O
LBA	B-Device
)	O
to	O
the	O
$MFT	O
,	O
which	O
is	O
described	O
below	O
.	O
</s>
<s>
In	O
NTFS	B-Application
,	O
all	O
file	O
,	O
directory	O
and	O
metafile	O
data	O
—	O
file	O
name	O
,	O
creation	O
date	O
,	O
access	O
permissions	O
(	O
by	O
the	O
use	O
of	O
access	O
control	O
lists	O
)	O
,	O
and	O
size	O
—	O
are	O
stored	O
as	O
metadata	O
in	O
the	O
Master	O
File	O
Table	O
(	O
MFT	O
)	O
.	O
</s>
<s>
This	O
abstract	O
approach	O
allowed	O
easy	O
addition	O
of	O
file	O
system	O
features	O
during	O
Windows	B-Device
NT	I-Device
's	O
development	O
—	O
an	O
example	O
is	O
the	O
addition	O
of	O
fields	O
for	O
indexing	O
used	O
by	O
the	O
Active	B-Protocol
Directory	I-Protocol
and	O
the	O
Windows	B-Application
Search	I-Application
.	O
</s>
<s>
The	O
MFT	O
structure	O
supports	O
algorithms	O
which	O
minimize	O
disk	B-Application
fragmentation	I-Application
.	O
</s>
<s>
A	O
directory	O
entry	O
consists	O
of	O
a	O
filename	O
and	O
a	O
"	O
file	O
ID	O
"	O
(	O
analogous	O
to	O
the	O
inode	B-Application
number	I-Application
)	O
,	O
which	O
is	O
the	O
record	O
number	O
representing	O
the	O
file	O
in	O
the	O
Master	O
File	O
Table	O
.	O
</s>
<s>
While	O
this	O
strongly	O
resembles	O
the	O
W_FID	O
of	O
Files-11	B-Application
,	O
other	O
NTFS	B-Application
structures	O
radically	O
differ	O
.	O
</s>
<s>
If	O
the	O
first	O
record	O
of	O
the	O
MFT	O
is	O
corrupted	O
,	O
NTFS	B-Application
reads	O
the	O
second	O
record	O
to	O
find	O
the	O
MFT	O
mirror	O
file	O
.	O
</s>
<s>
NTFS	B-Application
contains	O
several	O
files	O
that	O
define	O
and	O
organize	O
the	O
file	O
system	O
.	O
</s>
<s>
These	O
metafiles	O
define	O
files	O
,	O
back	O
up	O
critical	O
file	O
system	O
data	O
,	O
buffer	O
file	O
system	O
changes	O
,	O
manage	O
free	O
space	O
allocation	O
,	O
satisfy	O
BIOS	B-Operating_System
expectations	O
,	O
track	O
bad	O
allocation	O
units	O
,	O
and	O
store	O
security	O
and	O
disk	O
space	O
usage	O
information	O
.	O
</s>
<s>
+	O
MFT	O
(	O
entries	O
0	O
–	O
26	O
are	O
the	O
NTFS	B-Application
metafiles	O
)	O
Segment	O
number	O
File	O
name	O
Purpose	O
0	O
$MFT	O
Describes	O
all	O
files	O
on	O
the	O
volume	O
,	O
including	O
file	O
names	O
,	O
timestamps	O
,	O
stream	O
names	O
,	O
and	O
lists	O
of	O
cluster	O
numbers	O
where	O
data	O
streams	O
reside	O
,	O
indexes	O
,	O
security	O
identifiers	O
,	O
and	O
file	O
attributes	O
like	O
"	O
read	O
only	O
"	O
,	O
"	O
compressed	B-General_Concept
"	O
,	O
"	O
encrypted	O
"	O
,	O
etc	O
.	O
</s>
<s>
3	O
$Volume	O
Contains	O
information	O
about	O
the	O
volume	O
,	O
namely	O
the	O
volume	O
object	O
identifier	O
,	O
volume	O
label	O
,	O
file	O
system	O
version	O
,	O
and	O
volume	O
flags	O
(	O
mounted	O
,	O
chkdsk	B-Device
requested	O
,	O
requested	O
resize	O
,	O
mounted	O
on	O
NT	B-Device
4	I-Device
,	O
volume	B-Application
serial	I-Application
number	I-Application
updating	O
,	O
structure	O
upgrade	O
request	O
)	O
.	O
</s>
<s>
Note	O
:	O
volume	B-Application
serial	I-Application
number	I-Application
is	O
stored	O
in	O
file	O
(	O
below	O
)	O
.	O
</s>
<s>
Root	B-Application
directory	I-Application
.	O
</s>
<s>
7	O
$Boot	O
Volume	B-Device
boot	I-Device
record	I-Device
(	O
VBR	O
)	O
.	O
</s>
<s>
This	O
file	O
is	O
always	O
located	O
at	O
the	O
first	O
clusters	B-Application
on	O
the	O
volume	O
.	O
</s>
<s>
It	O
contains	O
bootstrap	O
code	O
(	O
see	O
NTLDR/BOOTMGR	O
)	O
and	O
a	O
BIOS	B-Device
parameter	I-Device
block	I-Device
including	O
a	O
volume	B-Application
serial	I-Application
number	I-Application
and	O
cluster	O
numbers	O
of	O
and	O
.	O
</s>
<s>
8	O
$BadClus	O
A	O
file	O
that	O
contains	O
all	O
the	O
clusters	B-Application
marked	O
as	O
having	O
bad	B-Device
sectors	I-Device
.	O
</s>
<s>
This	O
file	O
simplifies	O
cluster	O
management	O
by	O
the	O
chkdsk	B-Device
utility	O
,	O
both	O
as	O
a	O
place	O
to	O
put	O
newly	O
discovered	O
bad	B-Device
sectors	I-Device
,	O
and	O
for	O
identifying	O
unreferenced	O
clusters	B-Application
.	O
</s>
<s>
This	O
file	O
contains	O
two	O
data	O
streams	O
,	O
even	O
on	O
volumes	O
with	O
no	O
bad	B-Device
sectors	I-Device
:	O
an	O
unnamed	O
stream	O
contains	O
bad	B-Device
sectors	I-Device
—	O
it	O
is	O
zero	O
length	O
for	O
perfect	O
volumes	O
;	O
the	O
second	O
stream	O
is	O
named	O
and	O
contains	O
all	O
clusters	B-Application
on	O
the	O
volume	O
not	O
in	O
the	O
first	O
stream	O
.	O
</s>
<s>
10	O
$UpCase	O
A	O
table	O
of	O
unicode	O
uppercase	O
characters	O
for	O
ensuring	O
case-insensitivity	O
in	O
Win32	B-Library
and	O
DOS	O
namespaces	O
.	O
</s>
<s>
24	O
$Extend	O
\$Quota	O
Holds	O
disk	B-Application
quota	I-Application
information	O
.	O
</s>
<s>
26	O
$Extend	O
\$Reparse	O
Holds	O
reparse	B-Application
point	I-Application
data	O
(	O
such	O
as	O
symbolic	B-Application
links	I-Application
)	O
.	O
</s>
<s>
These	O
metafiles	O
are	O
treated	O
specially	O
by	O
Windows	O
,	O
handled	O
directly	O
by	O
the	O
NTFS.SYS	O
driver	O
and	O
are	O
difficult	O
to	O
directly	O
view	O
:	O
special	O
purpose-built	O
tools	O
are	O
needed	O
.	O
</s>
<s>
As	O
of	O
Windows	B-Device
7	I-Device
,	O
the	O
NTFS	B-Application
driver	O
completely	O
prohibits	O
user	O
access	O
,	O
resulting	O
in	O
a	O
BSoD	B-Error_Name
whenever	O
an	O
attempt	O
to	O
execute	O
a	O
metadata	O
file	O
is	O
made	O
.	O
</s>
<s>
One	O
such	O
tool	O
is	O
the	O
nfi.exe	O
(	O
"	O
NTFS	B-Application
File	O
Sector	O
Information	O
Utility	O
"	O
)	O
that	O
is	O
freely	O
distributed	O
as	O
part	O
of	O
the	O
Microsoft	O
"	O
OEM	O
Support	O
Tools	O
"	O
.	O
</s>
<s>
For	O
example	O
,	O
to	O
obtain	O
information	O
on	O
the	O
"	O
$MFT	O
"	O
-Master	O
File	O
Table	O
Segment	O
the	O
following	O
command	O
is	O
used	O
:	O
nfi.exe	O
c:\$MFT	O
Another	O
way	O
to	O
bypass	O
the	O
restriction	O
is	O
to	O
use	O
7-Zip	B-Language
'	O
s	O
file	O
manager	O
and	O
go	O
to	O
the	O
low-level	O
NTFS	B-Application
path	O
\\.\X:\	O
(	O
where	O
X:\	O
resembles	O
any	O
drive/partition	O
)	O
.	O
</s>
<s>
Here	O
,	O
3	O
new	O
folders	O
will	O
appear	O
:	O
$EXTEND	O
,	O
 [ DELETED ] 	O
(	O
a	O
pseudo-folder	O
that	O
7-Zip	B-Language
uses	O
to	O
attach	O
files	O
deleted	O
from	O
the	O
file	O
system	O
to	O
view	O
)	O
,	O
and	O
 [ SYSTEM ] 	O
(	O
another	O
pseudo-folder	O
that	O
contains	O
all	O
the	O
NTFS	B-Application
metadata	O
files	O
)	O
.	O
</s>
<s>
This	O
trick	O
can	O
be	O
used	O
from	O
removable	O
devices	O
(	O
USB	B-Protocol
flash	O
drives	O
,	O
external	O
hard	B-Device
drives	I-Device
,	O
SD	B-Device
Cards	I-Device
,	O
etc	O
.	O
)	O
</s>
<s>
inside	O
Windows	O
,	O
but	O
doing	O
this	O
on	O
the	O
active	O
partition	B-Application
requires	O
offline	O
access	O
(	O
namely	O
WinRE	O
)	O
.	O
</s>
<s>
For	O
NTFS	B-Application
,	O
the	O
standard	O
data	O
of	O
files	O
,	O
the	O
alternate	O
data	O
streams	O
,	O
or	O
the	O
index	O
data	O
for	O
directories	O
are	O
stored	O
as	O
attributes	O
.	O
</s>
<s>
Otherwise	O
,	O
clusters	B-Application
are	O
allocated	O
for	O
the	O
data	O
,	O
and	O
the	O
cluster	O
location	O
information	O
is	O
stored	O
as	O
data	O
runs	O
in	O
the	O
attribute	O
.	O
</s>
<s>
Additionally	O
,	O
NTFS	B-Application
has	O
some	O
ordering	O
constraints	O
for	O
these	O
attributes	O
.	O
</s>
<s>
This	O
is	O
the	O
case	O
for	O
the	O
attribute	O
that	O
is	O
stored	O
as	O
a	O
fixed-size	O
record	O
and	O
contains	O
the	O
timestamps	O
and	O
other	O
basic	O
single-bit	O
attributes	O
(	O
compatible	O
with	O
those	O
managed	O
by	O
FAT	B-Application
in	O
DOS	O
or	O
Windows	O
9x	O
)	O
.	O
</s>
<s>
This	O
is	O
the	O
case	O
for	O
the	O
standard	O
attributes	O
,	O
or	O
for	O
the	O
preferred	O
NTFS	B-Application
"	O
filename	O
"	O
attribute	O
type	O
,	O
or	O
the	O
"	O
short	O
filename	O
"	O
attribute	O
type	O
,	O
when	O
it	O
is	O
also	O
present	O
(	O
for	O
compatibility	O
with	O
DOS-like	O
applications	O
,	O
see	O
below	O
)	O
.	O
</s>
<s>
The	O
filename	O
attributes	O
stored	O
in	O
the	O
attribute	O
list	O
do	O
not	O
make	O
the	O
file	O
immediately	O
accessible	O
through	O
the	O
hierarchical	B-Application
file	I-Application
system	I-Application
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
the	O
default	O
data	O
stream	O
of	O
directories	O
has	O
a	O
distinct	O
type	O
,	O
but	O
are	O
not	O
anonymous	O
:	O
they	O
have	O
an	O
attribute	O
name	O
(""	O
in	O
NTFS	B-Application
3+	O
)	O
that	O
reflects	O
its	O
indexing	O
format	O
.	O
</s>
<s>
All	O
attributes	O
of	O
a	O
given	O
file	O
may	O
be	O
displayed	O
by	O
using	O
the	O
nfi.exe	O
(	O
"	O
NTFS	B-Application
File	O
Sector	O
Information	O
Utility	O
"	O
)	O
that	O
is	O
freely	O
distributed	O
as	O
part	O
of	O
the	O
Microsoft	O
"	O
OEM	O
Support	O
Tools	O
"	O
.	O
</s>
<s>
Depending	O
on	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
utility	O
and	O
remote	O
file	O
system	O
,	O
a	O
file	O
transfer	O
might	O
silently	O
strip	O
data	O
streams	O
.	O
</s>
<s>
To	O
optimize	O
the	O
storage	O
and	O
reduce	O
the	O
I/O	O
overhead	O
for	O
the	O
very	O
common	O
case	O
of	O
attributes	O
with	O
very	O
small	O
associated	O
value	O
,	O
NTFS	B-Application
prefers	O
to	O
place	O
the	O
value	O
within	O
the	O
attribute	O
itself	O
(	O
if	O
the	O
size	O
of	O
the	O
attribute	O
does	O
not	O
then	O
exceed	O
the	O
maximum	O
size	O
of	O
an	O
MFT	O
record	O
)	O
,	O
instead	O
of	O
using	O
the	O
MFT	O
record	O
space	O
to	O
list	O
clusters	B-Application
containing	O
the	O
data	O
;	O
in	O
that	O
case	O
,	O
the	O
attribute	O
will	O
not	O
store	O
the	O
data	O
directly	O
but	O
will	O
just	O
store	O
an	O
allocation	O
map	O
(	O
in	O
the	O
form	O
of	O
data	O
runs	O
)	O
pointing	O
to	O
the	O
actual	O
data	O
stored	O
elsewhere	O
on	O
the	O
volume	O
.	O
</s>
<s>
Encrypted-by-NTFS	O
,	O
sparse	O
data	O
streams	O
,	O
or	O
compressed	B-General_Concept
data	I-General_Concept
streams	O
cannot	O
be	O
made	O
resident	O
.	O
</s>
<s>
In	O
the	O
current	O
implementation	O
of	O
NTFS	B-Application
,	O
once	O
a	O
non-resident	O
data	O
stream	O
has	O
been	O
marked	O
and	O
converted	O
as	O
sparse	O
,	O
it	O
cannot	O
be	O
changed	O
back	O
to	O
non-sparse	O
data	O
,	O
so	O
it	O
cannot	O
become	O
resident	O
again	O
,	O
unless	O
this	O
data	O
is	O
fully	O
truncated	O
,	O
discarding	O
the	O
sparse	O
allocation	O
map	O
completely	O
.	O
</s>
<s>
When	O
a	O
non-resident	O
attribute	O
is	O
so	O
fragmented	O
,	O
that	O
its	O
effective	O
allocation	O
map	O
cannot	O
fit	O
entirely	O
within	O
one	O
MFT	O
record	O
,	O
NTFS	B-Application
stores	O
the	O
attribute	O
in	O
multiple	O
records	O
.	O
</s>
<s>
NTFS	B-Application
creates	O
a	O
special	O
attribute	O
to	O
store	O
information	O
mapping	O
different	O
parts	O
of	O
the	O
long	O
attribute	O
to	O
the	O
MFT	O
records	O
,	O
which	O
means	O
the	O
allocation	O
map	O
may	O
be	O
split	O
into	O
multiple	O
records	O
.	O
</s>
<s>
The	O
allocation	O
map	O
is	O
stored	O
in	O
a	O
form	O
of	O
data	O
runs	O
with	O
compressed	B-General_Concept
encoding	O
.	O
</s>
<s>
Each	O
data	O
run	O
represents	O
a	O
contiguous	O
group	O
of	O
clusters	B-Application
that	O
store	O
the	O
attribute	O
value	O
.	O
</s>
<s>
However	O
,	O
as	O
the	O
also	O
has	O
a	O
size	O
limit	O
,	O
it	O
is	O
dangerous	O
to	O
have	O
more	O
than	O
1	O
million	O
fragments	O
of	O
a	O
single	O
file	O
on	O
an	O
NTFS	B-Application
volume	O
,	O
which	O
also	O
implies	O
that	O
it	O
is	O
in	O
general	O
not	O
a	O
good	O
idea	O
to	O
use	O
NTFS	B-Application
compression	O
on	O
a	O
file	O
larger	O
than	O
.	O
</s>
<s>
The	O
NTFS	B-Application
file	I-Application
system	I-Application
driver	O
will	O
sometimes	O
attempt	O
to	O
relocate	O
the	O
data	O
of	O
some	O
of	O
the	O
attributes	O
that	O
can	O
be	O
made	O
non-resident	O
into	O
the	O
clusters	B-Application
,	O
and	O
will	O
also	O
attempt	O
to	O
relocate	O
the	O
data	O
stored	O
in	O
clusters	B-Application
back	O
to	O
the	O
attribute	O
inside	O
the	O
MFT	O
record	O
,	O
based	O
on	O
priority	O
and	O
preferred	O
ordering	O
rules	O
,	O
and	O
size	O
constraints	O
.	O
</s>
<s>
Since	O
resident	O
files	O
do	O
not	O
directly	O
occupy	O
clusters	B-Application
(	O
"	O
allocation	O
units	O
"	O
)	O
,	O
it	O
is	O
possible	O
for	O
an	O
NTFS	B-Application
volume	O
to	O
contain	O
more	O
files	O
on	O
a	O
volume	O
than	O
there	O
are	O
clusters	B-Application
.	O
</s>
<s>
For	O
example	O
,	O
a	O
partition	B-Application
NTFS	B-Application
formats	O
with	O
19,543,064	O
clusters	B-Application
of	O
.	O
</s>
<s>
Subtracting	O
system	O
files	O
(	O
a	O
log	O
file	O
,	O
a	O
2,442,888	O
-byte	O
Bitmap	O
file	O
,	O
and	O
about	O
25	O
clusters	B-Application
of	O
fixed	O
overhead	O
)	O
leaves	O
19,526,158	O
clusters	B-Application
free	O
for	O
files	O
and	O
indices	O
.	O
</s>
<s>
Opportunistic	O
locks	O
have	O
been	O
enhanced	O
in	O
Windows	B-Device
7	I-Device
and	O
Windows	B-Device
Server	I-Device
2008	I-Device
R2	I-Device
with	O
per-client	O
oplock	O
keys	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
and	O
its	O
descendants	O
keep	O
internal	O
timestamps	O
as	O
UTC	O
and	O
make	O
the	O
appropriate	O
conversions	O
for	O
display	O
purposes	O
;	O
all	O
NTFS	B-Application
timestamps	O
are	O
in	O
UTC	O
.	O
</s>
<s>
For	O
historical	O
reasons	O
,	O
the	O
versions	O
of	O
Windows	O
that	O
do	O
not	O
support	O
NTFS	B-Application
all	O
keep	O
time	O
internally	O
as	O
local	O
zone	O
time	O
,	O
and	O
therefore	O
so	O
do	O
all	O
file	O
systems	O
–	O
other	O
than	O
NTFS	B-Application
–	O
that	O
are	O
supported	O
by	O
current	O
versions	O
of	O
Windows	O
.	O
</s>
<s>
This	O
means	O
that	O
when	O
files	O
are	O
copied	O
or	O
moved	O
between	O
NTFS	B-Application
and	O
non-NTFS	O
partitions	B-Application
,	O
the	O
OS	O
needs	O
to	O
convert	B-Application
timestamps	O
on	O
the	O
fly	O
.	O
</s>
