<s>
Advanced	B-Device
Format	I-Device
(	O
AF	O
)	O
is	O
any	O
disk	B-Application
sector	I-Application
format	O
used	O
to	O
store	O
data	O
on	O
magnetic	O
disks	O
in	O
hard	B-Device
disk	I-Device
drives	I-Device
(	O
HDDs	O
)	O
that	O
exceeds	O
512	O
,	O
520	O
,	O
or	O
528	O
bytes	O
per	O
sector	O
,	O
such	O
as	O
the	O
4096	O
,	O
4112	O
,	O
4160	O
,	O
and	O
4224-byte	O
(	O
4KB	O
)	O
sectors	O
of	O
an	O
Advanced	B-Device
Format	I-Device
Drive	I-Device
(	O
AFD	O
)	O
.	O
</s>
<s>
Larger	O
sectors	O
enable	O
the	O
integration	O
of	O
stronger	O
error	B-Error_Name
correction	I-Error_Name
algorithms	O
to	O
maintain	O
data	O
integrity	O
at	O
higher	O
storage	B-Device
densities	I-Device
.	O
</s>
<s>
The	O
use	O
of	O
long	O
data	O
sectors	O
was	O
suggested	O
in	O
1998	O
in	O
a	O
technical	O
paper	O
issued	O
by	O
the	O
National	O
Storage	O
Industry	O
Consortium	O
(	O
NSIC	O
)	O
calling	O
attention	O
to	O
the	O
conflict	O
between	O
continuing	O
increases	O
in	O
areal	B-Device
density	I-Device
and	O
the	O
traditional	O
512-byte-per-sector	O
format	O
used	O
in	O
hard	B-Device
disk	I-Device
drives	I-Device
.	O
</s>
<s>
Without	O
revolutionary	O
breakthroughs	O
in	O
magnetic	O
recording	O
system	O
technologies	O
,	O
areal	B-Device
densities	I-Device
,	O
and	O
with	O
them	O
the	O
storage	O
capacities	O
,	O
hard	B-Device
disk	I-Device
drives	I-Device
were	O
projected	O
to	O
stagnate	O
.	O
</s>
<s>
The	O
storage	O
industry	O
trade	O
organization	O
,	O
International	O
Disk	O
Drive	O
Equipment	O
and	O
Materials	O
Association	O
(	O
IDEMA	B-Device
)	O
,	O
responded	O
by	O
organizing	O
the	O
IDEMA	B-Device
Long	O
Data	O
Sector	O
Committee	O
in	O
2000	O
,	O
where	O
IDEMA	B-Device
and	O
leading	O
hardware	O
and	O
software	O
suppliers	O
collaborated	O
on	O
the	O
definition	O
and	O
development	O
of	O
standards	O
governing	O
long	O
data	O
sectors	O
,	O
including	O
methods	O
by	O
which	O
compatibility	O
with	O
legacy	O
computing	O
components	O
would	O
be	O
supported	O
.	O
</s>
<s>
All	O
hard	B-Device
drive	I-Device
manufacturers	O
committed	O
to	O
shipping	O
new	O
hard	B-Device
drive	I-Device
platforms	O
for	O
desktop	O
and	O
notebook	O
products	O
with	O
the	O
Advanced	B-Device
Format	I-Device
sector	O
formatting	O
by	O
January	O
2011	O
.	O
</s>
<s>
Advanced	B-Device
Format	I-Device
was	O
coined	O
to	O
cover	O
what	O
was	O
expected	O
to	O
become	O
several	O
generations	O
of	O
long-data-sector	O
technologies	O
,	O
and	O
its	O
logo	O
was	O
created	O
to	O
distinguish	O
long-data-sector	O
–	O
based	O
hard	B-Device
disk	I-Device
drives	I-Device
from	O
those	O
using	O
legacy	O
512-byte	O
sector	O
.	O
</s>
<s>
Enterprise	O
disks	O
can	O
be	O
formatted	O
with	O
additional	O
8-byte	O
Data	B-Error_Name
Integrity	I-Error_Name
Fields	I-Error_Name
,	O
resulting	O
in	O
a	O
520	O
or	O
528-byte	O
physical	O
sectors	O
.	O
</s>
<s>
Generation-one	O
Advanced	B-Device
Format	I-Device
,	O
4K	O
sector	O
technology	O
,	O
uses	O
the	O
storage	O
surface	O
media	O
more	O
efficiently	O
by	O
combining	O
data	O
that	O
would	O
have	O
been	O
stored	O
in	O
eight	O
512-byte	O
sectors	O
into	O
one	O
single	O
sector	O
that	O
is	O
4096	O
bytes	O
(	O
4KB	O
)	O
in	O
length	O
.	O
</s>
<s>
Key	O
design	O
elements	O
of	O
the	O
traditional	O
512-byte	O
sector	O
architecture	O
are	O
maintained	O
,	O
specifically	O
,	O
the	O
identification	O
and	O
synchronization	O
marks	O
at	O
the	O
beginning	O
and	O
the	O
error	B-Error_Name
correction	I-Error_Name
coding	O
(	O
ECC	O
)	O
area	O
at	O
the	O
end	O
of	O
the	O
sector	O
.	O
</s>
<s>
The	O
Long	O
Data	O
Sector	O
Committee	O
selected	O
the	O
4K	O
block	O
length	O
for	O
the	O
first	O
generation	O
AF	O
standard	O
for	O
several	O
reasons	O
,	O
including	O
its	O
correspondence	O
to	O
the	O
paging	B-General_Concept
size	I-General_Concept
used	O
by	O
processors	B-General_Concept
and	O
some	O
operating	B-General_Concept
systems	I-General_Concept
as	O
well	O
as	O
its	O
correlation	O
to	O
the	O
size	O
of	O
standard	O
transactions	O
in	O
relational	B-Application
database	I-Application
systems	I-Application
.	O
</s>
<s>
The	O
Advanced	B-Device
Format	I-Device
standard	O
employs	O
the	O
same	O
gap	O
,	O
sync	O
and	O
address	O
mark	O
configuration	O
as	O
the	O
traditional	O
512-byte	O
sector	O
layout	O
,	O
but	O
combines	O
eight	O
512-byte	O
sectors	O
into	O
one	O
data	O
field	O
.	O
</s>
<s>
Having	O
a	O
huge	O
number	O
of	O
legacy	O
512-byte-sector	O
–	O
based	O
hard	B-Device
disk	I-Device
drives	I-Device
shipped	O
up	O
to	O
the	O
middle	O
of	O
2010	O
,	O
many	O
systems	O
,	O
programs	O
and	O
applications	O
accessing	O
the	O
hard	B-Device
disk	I-Device
drive	I-Device
are	O
designed	O
around	O
the	O
512-byte-per-sector	O
convention	O
.	O
</s>
<s>
Early	O
engagement	O
with	O
the	O
Long	O
Data	O
Sector	O
Committee	O
provided	O
the	O
opportunity	O
for	O
component	O
and	O
software	O
suppliers	O
to	O
prepare	O
for	O
the	O
transition	O
to	O
Advanced	B-Device
Format	I-Device
.	O
</s>
<s>
For	O
example	O
,	O
Windows	B-Application
Vista	I-Application
,	O
Windows	B-Device
7	I-Device
,	O
Windows	B-Device
Server	I-Device
2008	I-Device
,	O
and	O
Windows	B-Device
Server	I-Device
2008	I-Device
R2	I-Device
(	O
with	O
certain	O
hotfixes	O
installed	O
)	O
support	O
512e	O
format	O
drives	O
(	O
but	O
not	O
4Kn	O
)	O
,	O
as	O
do	O
contemporary	O
versions	O
of	O
FreeBSD	B-Operating_System
and	O
Linux	B-Operating_System
.	O
</s>
<s>
Mac	B-Application
OS	I-Application
X	I-Application
Tiger	I-Application
and	O
onwards	O
can	O
use	O
Advanced	B-Device
Format	I-Device
drives	I-Device
and	O
OS	B-Operating_System
X	I-Operating_System
Mountain	I-Operating_System
Lion	I-Operating_System
10.8.2	O
additionally	O
supports	O
encrypting	O
those	O
.	O
</s>
<s>
Windows	B-Application
8	I-Application
and	O
Windows	B-Device
Server	I-Device
2012	I-Device
also	O
support	O
4Kn	O
Advanced	B-Device
Format	I-Device
.	O
</s>
<s>
Oracle	B-Application
Solaris	I-Application
10	O
and	O
11	O
support	O
4Kn	O
and	O
512e	O
hard	B-Device
disk	I-Device
drives	I-Device
for	O
non-root	O
ZFS	O
file	B-Application
systems	I-Application
,	O
while	O
version	O
11.1	O
provides	O
installation	O
and	O
boot	O
support	O
for	O
512e	O
devices	O
.	O
</s>
<s>
Prior	O
to	O
Windows	B-Application
Vista	I-Application
,	O
Windows	B-Application
2000	I-Application
SP4	O
and	O
Windows	O
XP	O
SP2	O
will	O
use	O
2048	O
bytes	O
or	O
4096	O
bytes	O
as	O
default	O
allocation	O
unit	O
size	O
when	O
using	O
FAT	B-Application
to	O
format	O
removable	O
devices	O
such	O
as	O
USB	O
flash	O
drives	O
and	O
SD	B-Device
card	I-Device
.	O
</s>
<s>
Among	O
the	O
Advanced	B-Device
Format	I-Device
initiatives	O
undertaken	O
by	O
the	O
Long	O
Data	O
Sector	O
Committee	O
,	O
methods	O
to	O
maintain	O
backward	O
compatibility	O
with	O
legacy	O
computing	O
solutions	O
were	O
also	O
addressed	O
.	O
</s>
<s>
For	O
this	O
purpose	O
,	O
several	O
categories	O
of	O
Advanced	B-Device
Format	I-Device
devices	O
were	O
created	O
.	O
</s>
<s>
Many	O
host	O
computer	O
hardware	O
and	O
software	O
components	O
assume	O
the	O
hard	B-Device
drive	I-Device
is	O
configured	O
around	O
512-byte	O
sector	O
boundaries	O
.	O
</s>
<s>
This	O
includes	O
a	O
broad	O
range	O
of	O
items	O
including	O
chipsets	B-Device
,	O
operating	B-General_Concept
systems	I-General_Concept
,	O
database	B-General_Concept
engines	I-General_Concept
,	O
hard	B-Device
drive	I-Device
partitioning	B-Application
and	O
imaging	B-Application
tools	O
,	O
backup	B-Protocol
and	O
file	B-Application
system	I-Application
utilities	O
as	O
well	O
as	O
a	O
small	O
fraction	O
of	O
other	O
software	B-Application
applications	I-Application
.	O
</s>
<s>
In	O
order	O
to	O
maintain	O
compatibility	O
with	O
legacy	O
computing	O
components	O
,	O
many	O
hard	B-Device
disk	I-Device
drive	I-Device
suppliers	O
support	O
Advanced	B-Device
Format	I-Device
technologies	O
on	O
the	O
recording	O
media	O
coupled	O
with	O
512-byte	O
conversion	O
firmware	O
.	O
</s>
<s>
Hard	B-Device
drives	I-Device
configured	O
with	O
4096-byte	O
physical	O
sectors	O
with	O
512-byte	O
firmware	O
are	O
referred	O
to	O
as	O
Advanced	B-Device
Format	I-Device
512e	O
,	O
or	O
512	O
emulation	O
drives	O
.	O
</s>
<s>
The	O
translation	O
of	O
the	O
native	O
4096	O
,	O
4112	O
,	O
4160	O
,	O
or	O
4224-byte	O
physical	O
format	O
(	O
with	O
0	O
,	O
8	O
,	O
64	O
,	O
or	O
128-byte	O
Data	B-Error_Name
Integrity	I-Error_Name
Fields	I-Error_Name
)	O
to	O
a	O
virtual	O
512	O
,	O
520	O
or	O
528-byte	O
increment	O
is	O
transparent	O
to	O
the	O
entity	O
accessing	O
the	O
hard	B-Device
disk	I-Device
drive	I-Device
.	O
</s>
<s>
Read	O
and	O
write	O
commands	O
are	O
issued	O
to	O
Advanced	B-Device
Format	I-Device
drives	I-Device
in	O
the	O
same	O
format	O
as	O
legacy	O
drives	O
.	O
</s>
<s>
However	O
,	O
during	O
the	O
read	O
process	O
,	O
the	O
Advanced	B-Device
Format	I-Device
hard	B-Device
drive	I-Device
loads	O
the	O
entire	O
4096-byte	O
sector	O
containing	O
the	O
requested	O
512-byte	O
data	O
into	O
memory	O
located	O
on	O
the	O
drive	O
.	O
</s>
<s>
In	O
these	O
instances	O
,	O
the	O
hard	B-Device
drive	I-Device
must	O
read	O
the	O
entire	O
4096-byte	O
sector	O
containing	O
the	O
targeted	O
data	O
into	O
internal	O
memory	O
,	O
integrate	O
the	O
new	O
data	O
into	O
the	O
previously	O
existing	O
data	O
and	O
then	O
rewrite	O
the	O
entire	O
4096-byte	O
sector	O
onto	O
the	O
disk	O
media	O
.	O
</s>
<s>
This	O
operation	O
,	O
known	O
as	O
read-modify-write	B-Operating_System
(	O
RMW	B-Operating_System
)	O
,	O
can	O
require	O
additional	O
revolution	O
of	O
the	O
magnetic	O
disks	O
,	O
resulting	O
in	O
a	O
perceptible	O
performance	O
impact	O
to	O
the	O
system	O
user	O
.	O
</s>
<s>
Performance	O
analysis	O
conducted	O
by	O
IDEMA	B-Device
and	O
the	O
hard	B-Device
drive	I-Device
vendors	O
indicates	O
that	O
approximately	O
five	O
to	O
ten	O
percent	O
of	O
all	O
write	O
operations	O
in	O
a	O
typical	O
business	O
PC	O
user	O
environment	O
may	O
be	O
misaligned	O
and	O
a	O
RMW	B-Operating_System
performance	O
penalty	O
incurred	O
.	O
</s>
<s>
When	O
using	O
Advanced	B-Device
Format	I-Device
drives	I-Device
with	O
legacy	O
operating	B-General_Concept
systems	I-General_Concept
,	O
it	O
is	O
important	O
to	O
realign	O
the	O
disk	O
drive	O
using	O
software	O
provided	O
by	O
the	O
hard	B-Device
disk	I-Device
manufacturer	O
.	O
</s>
<s>
Disk	O
realignment	O
is	O
necessary	O
to	O
avoid	O
a	O
performance	O
degrading	O
condition	O
known	O
as	O
cluster	O
straddling	O
where	O
a	O
shifted	O
partition	B-Application
causes	O
filesystem	B-Application
clusters	O
to	O
span	O
partial	O
physical	O
disk	B-Application
sectors	I-Application
.	O
</s>
<s>
Since	O
cluster-to-sector	O
alignment	O
is	O
determined	O
when	O
creating	O
hard	B-Device
drive	I-Device
partitions	B-Application
,	O
the	O
realignment	O
software	O
is	O
used	O
after	O
partitioning	B-Application
the	O
disk	O
.	O
</s>
<s>
Further	O
activities	O
to	O
make	O
applications	O
ready	O
for	O
the	O
transition	O
to	O
Advanced	B-Device
Format	I-Device
technologies	O
were	O
spearheaded	O
by	O
the	O
Advanced	B-Device
Format	I-Device
Technology	O
Committee	O
(	O
formerly	O
Long	O
Data	O
Sector	O
Committee	O
)	O
and	O
by	O
the	O
hard	B-Device
disk	I-Device
drive	I-Device
manufacturers	O
.	O
</s>
<s>
For	O
hard	B-Device
disk	I-Device
drives	I-Device
working	O
in	O
the	O
4K	O
native	O
mode	O
,	O
there	O
is	O
no	O
emulation	O
layer	O
in	O
place	O
,	O
and	O
the	O
disk	O
media	O
directly	O
exposes	O
its	O
4096	O
,	O
4112	O
,	O
4160	O
,	O
or	O
4224-byte	O
physical	O
sector	O
size	O
to	O
the	O
system	O
firmware	O
and	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Since	O
April	O
2014	O
,	O
enterprise-class	O
4Knative	O
hard	B-Device
disk	I-Device
drives	I-Device
have	O
been	O
available	O
on	O
the	O
market	O
.	O
</s>
<s>
Readiness	O
of	O
the	O
support	O
for	O
4KB	O
logical	O
sectors	O
within	O
operating	B-General_Concept
systems	I-General_Concept
differs	O
among	O
their	O
types	O
,	O
vendors	O
and	O
versions	O
.	O
</s>
<s>
For	O
example	O
,	O
Microsoft	B-Application
Windows	I-Application
supports	O
4Knative	O
drives	O
since	O
Windows	O
8	O
and	O
Windows	B-Device
Server	I-Device
2012	I-Device
(	O
both	O
released	O
in	O
2012	O
)	O
in	O
UEFI	B-Architecture
.	O
</s>
<s>
Linux	B-Operating_System
supports	O
4Knative	O
drives	O
since	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
version	O
2.6.31	O
and	O
version	O
2.17	O
(	O
released	O
in	O
2009	O
and	O
2010	O
,	O
respectively	O
)	O
.	O
</s>
