<s>
Disk	B-Application
formatting	I-Application
is	O
the	O
process	O
of	O
preparing	O
a	O
data	B-General_Concept
storage	I-General_Concept
device	I-General_Concept
such	O
as	O
a	O
hard	B-Device
disk	I-Device
drive	I-Device
,	O
solid-state	B-Device
drive	I-Device
,	O
floppy	B-Device
disk	I-Device
,	O
memory	B-Device
card	I-Device
or	O
USB	O
flash	O
drive	O
for	O
initial	O
use	O
.	O
</s>
<s>
In	O
some	O
cases	O
,	O
the	O
formatting	O
operation	O
may	O
also	O
create	O
one	O
or	O
more	O
new	O
file	B-Application
systems	I-Application
.	O
</s>
<s>
The	O
first	O
part	O
of	O
the	O
formatting	O
process	O
that	O
performs	O
basic	O
medium	O
preparation	O
is	O
often	O
referred	O
to	O
as	O
"	O
low-level	B-Application
formatting	I-Application
"	O
.	O
</s>
<s>
Partitioning	B-Application
is	O
the	O
common	O
term	O
for	O
the	O
second	O
part	O
of	O
the	O
process	O
,	O
dividing	O
the	O
device	O
into	O
several	O
sub-devices	O
and	O
,	O
in	O
some	O
cases	O
,	O
writing	O
information	O
to	O
the	O
device	O
allowing	O
an	O
operating	B-General_Concept
system	I-General_Concept
to	O
be	O
booted	O
from	O
it	O
.	O
</s>
<s>
The	O
third	O
part	O
of	O
the	O
process	O
,	O
usually	O
termed	O
"	O
high-level	O
formatting	O
"	O
most	O
often	O
refers	O
to	O
the	O
process	O
of	O
generating	O
a	O
new	O
file	B-Application
system	I-Application
.	O
</s>
<s>
In	O
some	O
operating	B-General_Concept
systems	I-General_Concept
all	O
or	O
parts	O
of	O
these	O
three	O
processes	O
can	O
be	O
combined	O
or	O
repeated	O
at	O
different	O
levels	O
and	O
the	O
term	O
"	O
format	B-Application
"	O
is	O
understood	O
to	O
mean	O
an	O
operation	O
in	O
which	O
a	O
new	O
disk	O
medium	O
is	O
fully	O
prepared	O
to	O
store	O
files	B-Operating_System
.	O
</s>
<s>
Some	O
formatting	O
utilities	O
allow	O
distinguishing	O
between	O
a	O
quick	O
format	B-Application
,	O
which	O
does	O
not	O
erase	O
all	O
existing	O
data	O
and	O
a	O
long	O
option	O
that	O
does	O
erase	O
all	O
existing	O
data	O
.	O
</s>
<s>
As	O
a	O
general	O
rule	O
,	O
formatting	O
a	O
disk	O
by	O
default	O
leaves	O
most	O
if	O
not	O
all	O
existing	O
data	O
on	O
the	O
disk	O
medium	O
;	O
some	O
or	O
most	O
of	O
which	O
might	O
be	O
recoverable	O
with	O
privileged	O
or	O
special	B-Application
tools	I-Application
.	O
</s>
<s>
Special	B-Application
tools	I-Application
can	O
remove	O
user	O
data	O
by	O
a	O
single	O
overwrite	O
of	O
all	O
files	B-Operating_System
and	O
free	O
space	O
.	O
</s>
<s>
A	O
block	B-General_Concept
,	O
a	O
contiguous	O
number	O
of	O
bytes	B-Application
,	O
is	O
the	O
minimum	O
unit	O
of	O
storage	O
that	O
is	O
read	O
from	O
and	O
written	O
to	O
a	O
disk	O
by	O
a	O
disk	O
driver	O
.	O
</s>
<s>
The	O
earliest	O
disk	B-General_Concept
drives	I-General_Concept
had	O
fixed	O
block	B-General_Concept
sizes	I-General_Concept
(	O
e.g.	O
</s>
<s>
the	O
IBM	B-Device
350	I-Device
disk	O
storage	O
unit	O
(	O
of	O
the	O
late	O
1950s	O
)	O
block	B-General_Concept
size	I-General_Concept
was	O
100	O
six-bit	O
characters	O
)	O
but	O
starting	O
with	O
the	O
1301	B-Device
IBM	O
marketed	O
subsystems	O
that	O
featured	O
variable	B-Application
block	I-Application
sizes	I-Application
:	O
a	O
particular	O
track	O
could	O
have	O
blocks	O
of	O
different	O
sizes	O
.	O
</s>
<s>
The	O
disk	B-Device
subsystems	I-Device
and	O
other	O
Direct	B-Application
access	I-Application
storage	I-Application
devices	I-Application
on	O
the	O
IBM	B-Application
System/360	I-Application
expanded	O
this	O
concept	O
in	O
the	O
form	O
of	O
Count	B-Application
Key	I-Application
Data	I-Application
(	O
CKD	O
)	O
and	O
later	O
Extended	O
Count	B-Application
Key	I-Application
Data	I-Application
(	O
ECKD	O
)	O
;	O
however	O
the	O
use	O
of	O
variable	O
block	B-General_Concept
size	I-General_Concept
in	O
HDDs	O
fell	O
out	O
of	O
use	O
in	O
the	O
1990s	O
;	O
one	O
of	O
the	O
last	O
HDDs	O
to	O
support	O
variable	O
block	B-General_Concept
size	I-General_Concept
was	O
the	O
IBM	O
3390	O
Model	O
9	O
,	O
announced	O
May	O
1993	O
.	O
</s>
<s>
Modern	O
hard	B-Device
disk	I-Device
drives	I-Device
,	O
such	O
as	O
Serial	O
attached	O
SCSI	B-Architecture
(	O
SAS	O
)	O
and	O
Serial	O
ATA	O
(	O
SATA	O
)	O
drives	O
,	O
appear	O
at	O
their	O
interfaces	B-Application
as	O
a	O
contiguous	O
set	O
of	O
fixed-size	O
blocks	O
;	O
for	O
many	O
years	O
512	B-Application
bytes	I-Application
long	O
but	O
beginning	O
in	O
2009	O
and	O
accelerating	O
through	O
2011	O
,	O
all	O
major	O
hard	B-Device
disk	I-Device
drive	I-Device
manufacturers	O
began	O
releasing	O
hard	B-Device
disk	I-Device
drive	I-Device
platforms	O
using	O
the	O
Advanced	B-Device
Format	I-Device
of	O
4096	O
byte	B-Application
logical	O
blocks	O
.	O
</s>
<s>
Floppy	B-Device
disks	I-Device
generally	O
only	O
used	O
fixed	O
block	B-General_Concept
sizes	I-General_Concept
but	O
these	O
sizes	O
were	O
a	O
function	O
of	O
the	O
host	O
's	O
OS	B-General_Concept
and	O
its	O
interaction	O
with	O
its	O
controller	B-Device
so	O
that	O
a	O
particular	O
type	O
of	O
media	O
(	O
e.g.	O
,	O
5¼-inch	O
DSDD	O
)	O
would	O
have	O
different	O
block	B-General_Concept
sizes	I-General_Concept
depending	O
upon	O
the	O
host	O
OS	B-General_Concept
and	O
controller	B-Device
.	O
</s>
<s>
Optical	B-Device
discs	I-Device
generally	O
only	O
use	O
fixed	O
block	B-General_Concept
sizes	I-General_Concept
.	O
</s>
<s>
Formatting	O
a	O
disk	O
for	O
use	O
by	O
an	O
operating	B-General_Concept
system	I-General_Concept
and	O
its	O
applications	O
typically	O
involves	O
three	O
different	O
processes	O
.	O
</s>
<s>
Low-level	B-Application
formatting	I-Application
(	O
i.e.	O
,	O
closest	O
to	O
the	O
hardware	O
)	O
marks	O
the	O
surfaces	O
of	O
the	O
disks	O
with	O
markers	O
indicating	O
the	O
start	O
of	O
a	O
recording	O
block	B-General_Concept
(	O
typically	O
today	O
called	O
sector	B-Application
markers	O
)	O
and	O
other	O
information	O
like	O
block	B-General_Concept
CRC	O
to	O
be	O
used	O
later	O
,	O
in	O
normal	O
operations	O
,	O
by	O
the	O
disk	B-General_Concept
controller	I-General_Concept
to	O
read	O
or	O
write	O
data	O
.	O
</s>
<s>
Partitioning	B-Application
divides	O
a	O
disk	O
into	O
one	O
or	O
more	O
regions	O
,	O
writing	O
data	O
structures	O
to	O
the	O
disk	O
to	O
indicate	O
the	O
beginning	O
and	O
end	O
of	O
the	O
regions	O
.	O
</s>
<s>
High-level	O
formatting	O
creates	O
the	O
file	B-Application
system	I-Application
format	B-Application
within	O
a	O
disk	B-Application
partition	I-Application
or	O
a	O
logical	B-Application
volume	I-Application
.	O
</s>
<s>
This	O
formatting	O
includes	O
the	O
data	O
structures	O
used	O
by	O
the	O
OS	B-General_Concept
to	O
identify	O
the	O
logical	B-Application
drive	I-Application
or	O
partition	B-Application
's	O
contents	O
.	O
</s>
<s>
This	O
may	O
occur	O
during	O
operating	B-General_Concept
system	I-General_Concept
installation	O
,	O
or	O
when	O
adding	O
a	O
new	O
disk	O
.	O
</s>
<s>
Disk	B-Application
and	I-Application
distributed	I-Application
file	I-Application
system	I-Application
may	O
specify	O
an	O
optional	O
boot	B-Device
block	I-Device
,	O
and/or	O
various	O
volume	O
and	O
directory	O
information	O
for	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
The	O
low-level	B-Application
format	I-Application
of	O
floppy	B-Device
disks	I-Device
(	O
and	O
early	O
hard	B-Device
disks	I-Device
)	O
is	O
performed	O
by	O
the	O
disk	O
drive	O
's	O
controller	B-Device
.	O
</s>
<s>
For	O
a	O
standard	O
1.44	O
MB	O
floppy	B-Device
disk	I-Device
,	O
low-level	B-Application
formatting	I-Application
normally	O
writes	O
18	O
sectors	O
of	O
512	B-Application
bytes	I-Application
to	O
each	O
of	O
160	O
tracks	O
(	O
80	O
on	O
each	O
side	O
)	O
of	O
the	O
floppy	B-Device
disk	I-Device
,	O
providing	O
1,474,560	O
bytes	B-Application
of	O
storage	O
on	O
the	O
disk	O
.	O
</s>
<s>
Physical	O
sectors	O
are	O
actually	O
larger	O
than	O
512	B-Application
bytes	I-Application
,	O
as	O
in	O
addition	O
to	O
the	O
512	O
byte	B-Application
data	O
field	O
they	O
include	O
a	O
sector	B-Application
identifier	O
field	O
,	O
CRC	O
bytes	B-Application
(	O
in	O
some	O
cases	O
error	B-Error_Name
correction	I-Error_Name
bytes	I-Error_Name
)	O
and	O
gaps	O
between	O
the	O
fields	O
.	O
</s>
<s>
These	O
additional	O
bytes	B-Application
are	O
not	O
normally	O
included	O
in	O
the	O
quoted	O
figure	O
for	O
overall	O
storage	O
capacity	O
of	O
the	O
disk	O
.	O
</s>
<s>
Different	O
low-level	B-Application
formats	I-Application
can	O
be	O
used	O
on	O
the	O
same	O
media	O
;	O
for	O
example	O
,	O
large	O
records	O
can	O
be	O
used	O
to	O
cut	O
down	O
on	O
inter-record	O
gap	O
size	O
.	O
</s>
<s>
Several	O
freeware	B-License
,	O
shareware	B-License
and	O
free	B-Application
software	I-Application
programs	O
(	O
e.g.	O
</s>
<s>
GParted	B-Application
,	O
FDFORMAT	B-Application
,	O
NFORMAT	O
,	O
VGA-Copy	B-Device
and	O
2M	B-Application
)	O
allowed	O
considerably	O
more	O
control	O
over	O
formatting	O
,	O
allowing	O
the	O
formatting	O
of	O
high-density	O
3.5	B-Device
"	I-Device
disks	O
with	O
a	O
capacity	O
up	O
to	O
2	O
MB	O
.	O
</s>
<s>
head/track	O
sector	B-Application
skew	O
(	O
moving	O
the	O
sector	B-Application
numbering	O
forward	O
at	O
side	O
change	O
and	O
track	O
stepping	O
to	O
reduce	O
mechanical	O
delay	O
)	O
,	O
</s>
<s>
interleaving	B-Application
sectors	O
(	O
to	O
boost	O
throughput	O
by	O
organizing	O
the	O
sectors	O
on	O
the	O
track	O
)	O
,	O
</s>
<s>
Linux	B-Application
supports	O
a	O
variety	O
of	O
sector	B-Application
sizes	O
,	O
and	O
DOS	B-Device
and	O
Windows	B-Application
support	O
a	O
large-record-size	O
DMF-formatted	O
floppy	B-Device
format	B-Application
.	O
</s>
<s>
Hard	B-Device
disk	I-Device
drives	I-Device
prior	O
to	O
the	O
1990s	O
typically	O
had	O
a	O
separate	O
disk	B-General_Concept
controller	I-General_Concept
that	O
defined	O
how	O
data	O
was	O
encoded	O
on	O
the	O
media	O
.	O
</s>
<s>
With	O
the	O
media	O
,	O
the	O
drive	O
and/or	O
the	O
controller	B-Device
possibly	O
procured	O
from	O
separate	O
vendors	O
,	O
users	O
were	O
often	O
able	O
to	O
perform	O
low-level	B-Application
formatting	I-Application
.	O
</s>
<s>
User	O
instigated	O
low-level	B-Application
formatting	I-Application
(	O
LLF	O
)	O
of	O
hard	B-Device
disk	I-Device
drives	I-Device
was	O
common	O
for	O
minicomputer	B-Architecture
and	O
personal	B-Device
computer	I-Device
systems	O
until	O
the	O
1990s	O
.	O
</s>
<s>
IBM	O
and	O
other	O
mainframe	O
system	O
vendors	O
typically	O
supplied	O
their	O
hard	B-Device
disk	I-Device
drives	I-Device
(	O
or	O
media	O
in	O
the	O
case	O
of	O
removable	O
media	O
HDDs	O
)	O
with	O
a	O
low-level	B-Application
format	I-Application
.	O
</s>
<s>
Different	O
computers	O
used	O
different	O
block	B-General_Concept
sizes	I-General_Concept
and	O
IBM	O
notably	O
used	O
variable	B-Application
block	I-Application
sizes	I-Application
but	O
the	O
popularity	O
of	O
the	O
IBM	O
PC	O
caused	O
the	O
industry	O
to	O
adopt	O
a	O
standard	O
of	O
512	O
user	O
data	O
bytes	B-Application
per	O
block	B-General_Concept
by	O
the	O
middle	O
1980s	O
.	O
</s>
<s>
Depending	O
upon	O
the	O
system	O
,	O
low-level	B-Application
formatting	I-Application
was	O
generally	O
done	O
by	O
an	O
operating	B-General_Concept
system	I-General_Concept
utility	O
.	O
</s>
<s>
IBM	O
compatible	O
PCs	B-Device
used	O
the	O
BIOS	O
,	O
which	O
is	O
invoked	O
using	O
the	O
MS-DOS	B-Device
debug	I-Device
program	O
,	O
to	O
transfer	O
control	O
to	O
a	O
routine	O
hidden	O
at	O
different	O
addresses	O
in	O
different	O
BIOSes	O
.	O
</s>
<s>
Starting	O
in	O
the	O
late	O
1980s	O
,	O
driven	O
by	O
the	O
volume	O
of	O
IBM	O
compatible	O
PCs	B-Device
,	O
HDDs	O
became	O
routinely	O
available	O
pre-formatted	O
with	O
a	O
compatible	O
low-level	B-Application
format	I-Application
.	O
</s>
<s>
At	O
the	O
same	O
time	O
,	O
the	O
industry	O
moved	O
from	O
historical	O
(	O
dumb	O
)	O
bit	O
serial	O
interfaces	B-Application
to	O
modern	O
(	O
intelligent	O
)	O
bit	O
serial	O
interfaces	B-Application
and	O
word	O
serial	O
interfaces	B-Application
wherein	O
the	O
low-level	B-Application
format	I-Application
was	O
performed	O
at	O
the	O
factory	O
.	O
</s>
<s>
Accordingly	O
,	O
it	O
is	O
not	O
possible	O
for	O
an	O
end	O
user	O
to	O
low-level	B-Application
format	I-Application
a	O
modern	O
hard	B-Device
disk	I-Device
drive	I-Device
.	O
</s>
<s>
While	O
it	O
is	O
generally	O
impossible	O
to	O
perform	O
a	O
complete	O
LLF	O
on	O
most	O
modern	O
hard	B-Device
drives	I-Device
(	O
since	O
the	O
mid-1990s	O
)	O
outside	O
the	O
factory	O
,	O
the	O
term	O
"	O
low-level	B-Application
format	I-Application
"	O
is	O
still	O
used	O
for	O
what	O
could	O
be	O
called	O
the	O
reinitialization	O
of	O
a	O
hard	B-Device
drive	I-Device
to	O
its	O
factory	O
configuration	O
(	O
and	O
even	O
these	O
terms	O
may	O
be	O
misunderstood	O
)	O
.	O
</s>
<s>
The	O
present	O
ambiguity	O
in	O
the	O
term	O
low-level	B-Application
format	I-Application
seems	O
to	O
be	O
due	O
to	O
both	O
inconsistent	O
documentation	O
on	O
web	O
sites	O
and	O
the	O
belief	O
by	O
many	O
users	O
that	O
any	O
process	O
below	O
a	O
high-level	O
(	O
file	B-Application
system	I-Application
)	O
format	B-Application
must	O
be	O
called	O
a	O
low-level	B-Application
format	I-Application
.	O
</s>
<s>
Since	O
much	O
of	O
the	O
low-level	B-Application
formatting	I-Application
process	O
can	O
today	O
only	O
be	O
performed	O
at	O
the	O
factory	O
,	O
various	O
drive	O
manufacturers	O
describe	O
reinitialization	O
software	O
as	O
LLF	O
utilities	O
on	O
their	O
web	O
sites	O
.	O
</s>
<s>
Since	O
users	O
generally	O
have	O
no	O
way	O
to	O
determine	O
the	O
difference	O
between	O
a	O
complete	O
LLF	O
and	O
reinitialization	O
(	O
they	O
simply	O
observe	O
running	O
the	O
software	O
results	O
in	O
a	O
hard	B-Device
disk	I-Device
that	O
must	O
be	O
high-level	O
formatted	O
)	O
,	O
both	O
the	O
misinformed	O
user	O
and	O
mixed	O
signals	O
from	O
various	O
drive	O
manufacturers	O
have	O
perpetuated	O
this	O
error	O
.	O
</s>
<s>
Note	O
:	O
whatever	O
possible	O
misuse	O
of	O
such	O
terms	O
may	O
exist	O
,	O
many	O
sites	O
do	O
make	O
such	O
reinitialization	O
utilities	O
available	O
(	O
possibly	O
as	O
bootable	O
floppy	B-Device
diskette	I-Device
or	O
CD	O
image	O
files	B-Operating_System
)	O
,	O
to	O
both	O
overwrite	O
every	O
byte	B-Application
and	O
check	O
for	O
damaged	O
sectors	O
on	O
the	O
hard	B-Device
disk	I-Device
.	O
</s>
<s>
The	O
term	O
has	O
,	O
however	O
,	O
been	O
used	O
by	O
some	O
to	O
refer	O
to	O
only	O
a	O
portion	O
of	O
that	O
process	O
,	O
in	O
which	O
every	O
sector	B-Application
of	O
the	O
drive	O
is	O
written	O
to	O
;	O
usually	O
by	O
writing	O
a	O
specific	O
value	O
to	O
every	O
addressable	O
location	O
on	O
the	O
disk	O
.	O
</s>
<s>
Traditionally	O
,	O
the	O
physical	O
sectors	O
were	O
initialized	O
with	O
a	O
fill	O
value	O
of	O
0xF6	O
as	O
per	O
the	O
INT1Eh	O
's	O
Disk	O
Parameter	O
Table	O
(	O
DPT	O
)	O
during	O
format	B-Application
on	O
IBM	O
compatible	O
machines	O
.	O
</s>
<s>
This	O
value	O
is	O
also	O
used	O
on	O
the	O
Atari	B-Device
Portfolio	I-Device
.	O
</s>
<s>
CP/M	B-Application
8-inch	O
floppies	B-Device
typically	O
came	O
pre-formatted	O
with	O
a	O
value	O
of	O
0xE5	O
,	O
and	O
by	O
way	O
of	O
Digital	O
Research	O
this	O
value	O
was	O
also	O
used	O
on	O
Atari	B-Device
ST	I-Device
and	O
some	O
Amstrad	O
formatted	O
floppies	B-Device
.	O
</s>
<s>
Some	O
modern	O
formatters	O
wipe	O
hard	B-Device
disks	I-Device
with	O
a	O
value	O
of	O
0x00	O
instead	O
,	O
sometimes	O
also	O
called	O
zero-filling	O
,	O
whereas	O
a	O
value	O
of	O
0xFF	O
is	O
used	O
on	O
flash	O
disks	O
to	O
reduce	O
wear	O
.	O
</s>
<s>
One	O
popular	O
method	O
for	O
performing	O
only	O
the	O
zero-fill	O
operation	O
on	O
a	O
hard	B-Device
disk	I-Device
is	O
by	O
writing	O
zero-value	O
bytes	B-Application
to	O
the	O
drive	O
using	O
the	O
Unix	B-Application
dd	I-Application
utility	O
with	O
the	O
/dev/zero	B-Application
stream	O
as	O
the	O
input	O
file	O
and	O
the	O
drive	O
itself	O
(	O
or	O
a	O
specific	O
partition	B-Application
)	O
as	O
the	O
output	O
file	O
.	O
</s>
<s>
This	O
command	B-Application
may	O
take	O
many	O
hours	O
to	O
complete	O
,	O
and	O
can	O
erase	O
all	O
files	B-Operating_System
and	O
file	B-Application
systems	I-Application
.	O
</s>
<s>
Another	O
method	O
for	O
SCSI	B-Architecture
disks	O
may	O
be	O
to	O
use	O
the	O
sg_format	O
command	B-Application
to	O
issue	O
a	O
low-level	O
SCSI	B-Architecture
Format	B-Application
Unit	O
Command	B-Application
.	O
</s>
<s>
Zero-filling	O
a	O
drive	O
is	O
not	O
necessarily	O
a	O
secure	O
method	O
of	O
erasing	O
sensitive	O
data	O
,	O
or	O
of	O
preparing	O
a	O
drive	O
for	O
use	O
with	O
an	O
encrypted	O
filesystem	B-Application
.	O
</s>
<s>
Partitioning	B-Application
is	O
the	O
process	O
of	O
writing	O
information	O
into	O
blocks	O
of	O
a	O
storage	O
device	O
or	O
medium	O
to	O
divide	O
the	O
device	O
into	O
several	O
sub-devices	O
,	O
each	O
of	O
which	O
is	O
treated	O
by	O
the	O
operating	B-General_Concept
system	I-General_Concept
as	O
a	O
separate	O
device	O
and	O
,	O
in	O
some	O
cases	O
,	O
to	O
allow	O
an	O
operating	B-General_Concept
system	I-General_Concept
to	O
be	O
booted	O
from	O
the	O
device	O
.	O
</s>
<s>
On	O
MS-DOS	B-Application
,	O
Microsoft	B-Application
Windows	I-Application
,	O
and	O
UNIX-based	O
operating	B-General_Concept
systems	I-General_Concept
(	O
such	O
as	O
BSD	B-Operating_System
,	O
Linux	B-Application
and	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
)	O
this	O
is	O
normally	O
done	O
with	O
a	O
partition	B-Application
editor	O
,	O
such	O
as	O
fdisk	B-Application
,	O
GNU	B-Application
Parted	I-Application
,	O
or	O
Disk	B-Application
Utility	I-Application
.	O
</s>
<s>
These	O
operating	B-General_Concept
systems	I-General_Concept
support	O
multiple	O
partitions	B-Application
.	O
</s>
<s>
Floppy	B-Device
disks	I-Device
are	O
not	O
partitioned	O
;	O
however	O
depending	O
upon	O
the	O
OS	B-General_Concept
they	O
may	O
require	O
volume	O
information	O
in	O
order	O
to	O
be	O
accessed	O
by	O
the	O
OS	B-General_Concept
.	O
</s>
<s>
Partition	B-Application
editors	O
and	O
ICKDSF	O
today	O
do	O
not	O
handle	O
low-level	O
functions	O
for	O
HDDs	O
and	O
optical	B-Device
disc	I-Device
drives	O
such	O
as	O
writing	O
timing	O
marks	O
,	O
and	O
they	O
cannot	O
reinitialize	O
a	O
modern	O
disk	O
that	O
has	O
been	O
degaussed	O
or	O
otherwise	O
lost	O
the	O
factory	O
formatting	O
.	O
</s>
<s>
IBM	O
operating	B-General_Concept
systems	I-General_Concept
derived	O
from	O
CP-67	B-Application
,	O
e.g.	O
,	O
z/VM	B-Application
,	O
maintain	O
partitioning	B-Application
information	O
for	O
minidisks	O
externally	O
to	O
the	O
drive	O
.	O
</s>
<s>
High-level	O
formatting	O
is	O
the	O
process	O
of	O
setting	O
up	O
an	O
empty	O
file	B-Application
system	I-Application
on	O
a	O
disk	B-Application
partition	I-Application
or	O
a	O
logical	B-Application
volume	I-Application
and	O
for	O
PCs	B-Device
,	O
installing	O
a	O
boot	B-Device
sector	I-Device
.	O
</s>
<s>
Formatting	O
an	O
entire	O
logical	B-Application
drive	I-Application
or	O
partition	B-Application
may	O
optionally	O
scanned	O
for	O
defects	O
,	O
which	O
may	O
take	O
considerable	O
time	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
floppy	B-Device
disks	I-Device
,	O
both	O
high	O
-	O
and	O
low-level	B-Application
formatting	I-Application
are	O
customarily	O
performed	O
in	O
one	O
pass	O
by	O
the	O
disk	B-Application
formatting	I-Application
software	O
.	O
</s>
<s>
Eight-inch	O
floppies	B-Device
typically	O
came	O
low-level	O
formatted	O
and	O
were	O
filled	O
with	O
a	O
format	B-Application
filler	O
value	O
of	O
0xE5	O
.	O
</s>
<s>
Since	O
the	O
1990s	O
,	O
most	O
5.25-inch	O
and	O
3.5-inch	O
floppies	B-Device
have	O
been	O
shipped	O
pre-formatted	O
from	O
the	O
factory	O
as	O
DOS	B-Device
FAT12	B-Application
floppies	B-Device
.	O
</s>
<s>
In	O
current	O
IBM	O
mainframe	O
operating	B-General_Concept
systems	I-General_Concept
derived	O
from	O
OS/360	B-Application
and	O
DOS/360	O
,	O
such	O
as	O
z/OS	B-Application
and	O
z/VSE	B-Application
,	O
formatting	O
of	O
drives	O
is	O
done	O
by	O
the	O
INIT	O
command	B-Application
of	O
the	O
ICKDSF	O
utility	O
.	O
</s>
<s>
These	O
OSs	O
support	O
only	O
a	O
single	O
partition	B-Application
per	O
device	O
,	O
called	O
a	O
volume	O
.	O
</s>
<s>
The	O
ICKDSF	O
functions	O
include	O
writing	O
a	O
Record	O
0	O
on	O
every	O
track	O
,	O
writing	O
IPL	O
text	O
,	O
creating	O
a	O
volume	O
label	O
,	O
creating	O
a	O
Volume	B-Application
Table	I-Application
of	I-Application
Contents	I-Application
(	O
VTOC	B-Application
)	O
and	O
,	O
optionally	O
,	O
creating	O
a	O
VTOC	B-Application
index	O
(	O
VTOCIX	O
)	O
;	O
high	O
level	O
formatting	O
may	O
also	O
e	O
done	O
as	O
part	O
of	O
allocating	O
a	O
file	O
,	O
by	O
a	O
utility	O
specific	O
to	O
a	O
file	B-Application
system	I-Application
or	O
,	O
in	O
some	O
older	O
access	O
methods	O
,	O
on	O
the	O
fly	O
as	O
new	O
data	O
are	O
written	O
.	O
</s>
<s>
In	O
z/OS	B-Application
Unix	B-Operating_System
System	I-Operating_System
Services	I-Operating_System
,	O
there	O
are	O
three	O
distinct	O
levels	O
of	O
high-level	O
formatting	O
:	O
</s>
<s>
Initializing	O
a	O
zFS	B-Application
aggregate	O
in	O
the	O
LDS	O
using	O
ioeagfmt	O
.	O
</s>
<s>
In	O
IBM	O
operating	B-General_Concept
systems	I-General_Concept
derived	O
from	O
CP-67	B-Application
,	O
formatting	O
a	O
volume	O
initializes	O
track	O
0	O
and	O
a	O
dummy	O
VTOC	B-Application
.	O
</s>
<s>
Guest	O
operating	B-General_Concept
systems	I-General_Concept
are	O
responsible	O
for	O
formatting	O
minidisks	O
;	O
the	O
CMS	O
FORMAT	B-Application
command	B-Application
formats	O
a	O
CMS	B-Application
file	I-Application
system	I-Application
on	O
a	O
CMS	O
minidisk	O
.	O
</s>
<s>
The	O
host	O
protected	O
area	O
,	O
sometimes	O
referred	O
to	O
as	O
hidden	O
protected	O
area	O
,	O
is	O
an	O
area	O
of	O
a	O
hard	B-Device
drive	I-Device
that	O
is	O
high-level	O
formatted	O
such	O
that	O
the	O
area	O
is	O
not	O
normally	O
visible	O
to	O
its	O
operating	B-General_Concept
system	I-General_Concept
(	O
OS	B-General_Concept
)	O
.	O
</s>
<s>
Reformatting	O
is	O
unique	O
to	O
each	O
operating	B-General_Concept
system	I-General_Concept
because	O
what	O
actually	O
is	O
done	O
to	O
existing	O
data	O
varies	O
by	O
OS	B-General_Concept
.	O
</s>
<s>
To	O
actually	O
"	O
erase	O
"	O
everything	O
requires	O
overwriting	O
each	O
block	B-General_Concept
of	O
data	O
on	O
the	O
medium	O
;	O
something	O
that	O
is	O
not	O
done	O
by	O
many	O
high-level	O
formatting	O
utilities	O
.	O
</s>
<s>
Reformatting	O
often	O
carries	O
the	O
implication	O
that	O
the	O
operating	B-General_Concept
system	I-General_Concept
and	O
all	O
other	O
software	O
will	O
be	O
reinstalled	O
after	O
the	O
format	B-Application
is	O
complete	O
.	O
</s>
<s>
Rather	O
than	O
fixing	O
an	O
installation	O
suffering	O
from	O
malfunction	O
or	O
security	O
compromise	O
,	O
it	O
may	O
be	O
necessary	O
to	O
simply	O
reformat	B-Application
everything	O
and	O
start	O
from	O
scratch	O
.	O
</s>
<s>
However	O
,	O
reformatting	O
a	O
drive	O
containing	O
only	O
user	O
data	O
does	O
not	O
require	O
reinstallation	O
of	O
the	O
OS	B-General_Concept
.	O
</s>
<s>
format	B-Application
command	B-Application
:	O
Under	O
MS-DOS	B-Application
,	O
PC	B-Operating_System
DOS	I-Operating_System
,	O
OS/2	B-Application
and	O
Microsoft	B-Application
Windows	I-Application
,	O
disk	B-Application
formatting	I-Application
can	O
be	O
performed	O
by	O
the	O
format	B-Application
command	B-Application
.	O
</s>
<s>
The	O
format	B-Application
program	I-Application
usually	O
asks	O
for	O
confirmation	O
beforehand	O
to	O
prevent	O
accidental	O
removal	O
of	O
data	O
,	O
but	O
some	O
versions	O
of	O
DOS	B-Device
have	O
an	O
undocumented	O
/AUTOTEST	O
option	O
;	O
if	O
used	O
,	O
the	O
usual	O
confirmation	O
is	O
skipped	O
and	O
the	O
format	B-Application
begins	O
right	O
away	O
.	O
</s>
<s>
The	O
WM/FormatC	O
macro	B-Application
virus	I-Application
uses	O
this	O
command	B-Application
to	O
format	B-Application
drive	O
C	O
:	O
as	O
soon	O
as	O
a	O
document	O
is	O
opened	O
.	O
</s>
<s>
Unconditional	O
format	B-Application
:	O
There	O
is	O
also	O
the	O
/U	O
parameter	O
that	O
performs	O
an	O
unconditional	O
format	B-Application
which	O
under	O
most	O
circumstances	O
overwrites	O
the	O
entire	O
partition	B-Application
,	O
preventing	O
the	O
recovery	O
of	O
data	O
through	O
software	O
.	O
</s>
<s>
Note	O
however	O
that	O
the	O
/U	O
switch	O
only	O
works	O
reliably	O
with	O
floppy	B-Device
diskettes	I-Device
(	O
see	O
image	O
to	O
the	O
right	O
)	O
.	O
</s>
<s>
Technically	O
because	O
unless	O
/Q	O
is	O
used	O
,	O
floppies	B-Device
are	O
always	O
low	O
level	O
formatted	O
in	O
addition	O
to	O
high-level	O
formatted	O
.	O
</s>
<s>
Under	O
certain	O
circumstances	O
with	O
hard	B-Device
drive	I-Device
partitions	B-Application
,	O
however	O
,	O
the	O
/U	O
switch	O
merely	O
prevents	O
the	O
creation	O
of	O
unformat	O
information	O
in	O
the	O
partition	B-Application
to	O
be	O
formatted	O
while	O
otherwise	O
leaving	O
the	O
partition	B-Application
's	O
contents	O
entirely	O
intact	O
(	O
still	O
on	O
disk	O
but	O
marked	O
deleted	O
)	O
.	O
</s>
<s>
In	O
such	O
cases	O
,	O
the	O
user	O
's	O
data	O
remain	O
ripe	O
for	O
recovery	O
with	O
specialist	O
tools	O
such	O
as	O
EnCase	O
or	O
disk	B-Application
editors	I-Application
.	O
</s>
<s>
Reliance	O
upon	O
/U	O
for	O
secure	O
overwriting	O
of	O
hard	B-Device
drive	I-Device
partitions	B-Application
is	O
therefore	O
inadvisable	O
,	O
and	O
purpose-built	O
tools	O
such	O
as	O
DBAN	O
should	O
be	O
considered	O
instead	O
.	O
</s>
<s>
Overwriting	O
:	O
In	O
Windows	B-Application
Vista	O
and	O
upwards	O
the	O
non-quick	O
format	B-Application
will	O
overwrite	O
as	O
it	O
goes	O
.	O
</s>
<s>
Not	O
the	O
case	O
in	O
Windows	B-Application
XP	O
and	O
below	O
.	O
</s>
<s>
OS/2	B-Application
:	O
Under	O
OS/2	B-Application
,	O
format	B-Application
will	O
overwrite	O
the	O
entire	O
partition	B-Application
or	O
logical	B-Application
drive	I-Application
if	O
the	O
/L	O
parameter	O
is	O
used	O
,	O
which	O
specifies	O
a	O
long	O
format	B-Application
.	O
</s>
<s>
Doing	O
so	O
enhances	O
the	O
ability	O
of	O
CHKDSK	B-Device
to	O
recover	O
files	B-Operating_System
.	O
</s>
<s>
High-level	O
formatting	O
of	O
disks	O
on	O
these	O
systems	O
is	O
traditionally	O
done	O
using	O
the	O
mkfs	B-Device
command	B-Application
.	O
</s>
<s>
On	O
Linux	B-Application
(	O
and	O
potentially	O
other	O
systems	O
as	O
well	O
)	O
mkfs	B-Device
is	O
typically	O
a	O
wrapper	O
around	O
filesystem-specific	O
commands	O
which	O
have	O
the	O
name	O
mkfs.fsname	O
,	O
where	O
fsname	O
is	O
the	O
name	O
of	O
the	O
filesystem	B-Application
with	O
which	O
to	O
format	B-Application
the	O
disk	O
.	O
</s>
<s>
Some	O
filesystems	B-Application
which	O
are	O
not	O
supported	O
by	O
certain	O
implementations	O
of	O
mkfs	B-Device
have	O
their	O
own	O
manipulation	O
tools	O
;	O
for	O
example	O
Ntfsprogs	B-Language
provides	O
a	O
format	B-Application
utility	O
for	O
the	O
NTFS	B-Application
filesystem	B-Application
.	O
</s>
<s>
Some	O
Unix	O
and	O
Unix-like	O
operating	B-General_Concept
systems	I-General_Concept
have	O
higher-level	O
formatting	O
tools	O
,	O
usually	O
for	O
the	O
purpose	O
of	O
making	O
disk	B-Application
formatting	I-Application
easier	O
and/or	O
allowing	O
the	O
user	O
to	O
partition	B-Application
the	O
disk	O
with	O
the	O
same	O
tool	O
.	O
</s>
<s>
Examples	O
include	O
GNU	B-Application
Parted	I-Application
(	O
and	O
its	O
various	O
GUI	O
frontends	O
such	O
as	O
GParted	B-Application
and	O
the	O
KDE	B-Language
Partition	I-Language
Manager	I-Language
)	O
and	O
the	O
Disk	B-Application
Utility	I-Application
application	O
on	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
.	O
</s>
<s>
As	O
in	O
file	O
deletion	O
by	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
data	O
on	O
a	O
disk	O
are	O
not	O
fully	O
erased	O
during	O
every	O
high-level	B-Application
format	I-Application
.	O
</s>
<s>
If	O
the	O
disk	O
is	O
formatted	O
with	O
a	O
different	O
file	B-Application
system	I-Application
than	O
the	O
one	O
which	O
previously	O
existed	O
on	O
the	O
partition	B-Application
,	O
some	O
data	O
may	O
be	O
overwritten	O
that	O
would	O
n't	O
be	O
if	O
the	O
same	O
file	B-Application
system	I-Application
had	O
been	O
used	O
.	O
</s>
<s>
However	O
,	O
under	O
some	O
file	B-Application
systems	I-Application
(	O
e.g.	O
,	O
NTFS	B-Application
,	O
but	O
not	O
FAT	O
)	O
,	O
the	O
file	O
indexes	O
(	O
such	O
as	O
$MFTs	O
under	O
NTFS	B-Application
,	O
inodes	O
under	O
ext2/3	O
,	O
etc	O
.	O
)	O
</s>
<s>
And	O
if	O
the	O
partition	B-Application
size	O
is	O
increased	O
,	O
even	O
FAT	O
file	B-Application
systems	I-Application
will	O
overwrite	O
more	O
data	O
at	O
the	O
beginning	O
of	O
that	O
new	O
partition	B-Application
.	O
</s>
<s>
From	O
the	O
perspective	O
of	O
preventing	O
the	O
recovery	O
of	O
sensitive	O
data	O
through	O
recovery	O
tools	O
,	O
the	O
data	O
must	O
either	O
be	O
completely	O
overwritten	O
(	O
every	O
sector	B-Application
)	O
with	O
random	O
data	O
before	O
the	O
format	B-Application
,	O
or	O
the	O
format	B-Application
program	I-Application
itself	O
must	O
perform	O
this	O
overwriting	O
,	O
as	O
the	O
DOS	B-Device
FORMAT	B-Application
command	B-Application
did	O
with	O
floppy	B-Device
diskettes	I-Device
,	O
filling	O
every	O
data	O
sector	B-Application
with	O
the	O
format	B-Application
filler	O
byte	B-Application
value	O
(	O
typically	O
0xF6	O
)	O
.	O
</s>
<s>
In	O
order	O
to	O
avoid	O
the	O
recovery	O
of	O
sensitive	O
data	O
,	O
governmental	O
organization	O
or	O
big	O
companies	O
use	O
information	O
destruction	O
methods	O
like	O
the	O
Gutmann	B-Algorithm
method	I-Algorithm
.	O
</s>
<s>
Although	O
there	O
are	O
applications	O
that	O
perform	O
multiple	O
writes	O
to	O
assure	O
data	O
erasure	O
,	O
any	O
single	O
write	O
over	O
old	O
data	O
is	O
generally	O
all	O
that	O
is	O
needed	O
on	O
modern	O
hard	B-Device
disk	I-Device
drives	I-Device
.	O
</s>
<s>
The	O
ATA	O
Secure	O
Erase	O
can	O
be	O
performed	O
by	O
disk	B-Application
utilities	I-Application
to	O
quickly	O
and	O
thoroughly	O
wipe	O
drives	O
.	O
</s>
