<s>
HFS	B-Application
Plus	I-Application
or	O
HFS+	B-Application
(	O
also	O
known	O
as	O
Mac	B-Application
OS	I-Application
Extended	I-Application
or	O
HFS	B-Application
Extended	O
)	O
is	O
a	O
journaling	B-Application
file	I-Application
system	I-Application
developed	O
by	O
Apple	O
Inc	O
.	O
</s>
<s>
It	O
replaced	O
the	O
Hierarchical	B-Application
File	I-Application
System	I-Application
(	O
HFS	B-Application
)	O
as	O
the	O
primary	O
file	O
system	O
of	O
Apple	O
computers	O
with	O
the	O
1998	O
release	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
8.1	I-Operating_System
.	O
</s>
<s>
HFS+	B-Application
continued	O
as	O
the	O
primary	O
Mac	B-Device
OS	I-Device
X	I-Device
file	O
system	O
until	O
it	O
was	O
itself	O
replaced	O
with	O
the	O
Apple	B-Application
File	I-Application
System	I-Application
(	O
APFS	B-Application
)	O
,	O
released	O
with	O
macOS	B-Operating_System
High	I-Operating_System
Sierra	I-Operating_System
in	O
2017	O
.	O
</s>
<s>
HFS+	B-Application
is	O
also	O
one	O
of	O
the	O
formats	O
supported	O
by	O
the	B-Device
iPod	I-Device
digital	O
music	O
player	O
.	O
</s>
<s>
Compared	O
to	O
its	O
predecessor	O
HFS	B-Application
,	O
also	O
called	O
Mac	B-Application
OS	I-Application
Standard	I-Application
or	O
HFS	B-Application
Standard	O
,	O
HFS	B-Application
Plus	I-Application
supports	O
much	O
larger	O
files	O
(	O
block	O
addresses	O
are	O
32-bit	O
length	O
instead	O
of	O
16-bit	O
)	O
and	O
using	O
Unicode	O
(	O
instead	O
of	O
Mac	B-Application
OS	I-Application
Roman	O
or	O
any	O
of	O
several	O
other	O
character	O
sets	O
)	O
for	O
naming	O
items	O
.	O
</s>
<s>
Like	O
HFS	B-Application
,	O
HFS	B-Application
Plus	I-Application
uses	O
B-trees	B-Architecture
to	O
store	O
most	O
volume	O
metadata	O
,	O
but	O
unlike	O
most	O
file	O
systems	O
that	O
support	O
hard	B-Application
links	I-Application
,	O
HFS	B-Application
Plus	I-Application
supports	O
hard	B-Application
links	I-Application
to	O
directories	O
.	O
</s>
<s>
HFS	B-Application
Plus	I-Application
permits	O
filenames	O
up	O
to	O
255	O
characters	O
in	O
length	O
,	O
and	O
n-forked	O
files	O
similar	O
to	O
NTFS	B-Application
,	O
though	O
until	O
2005	O
almost	O
no	O
system	B-Application
software	I-Application
took	O
advantage	O
of	O
forks	B-Application
other	O
than	O
the	O
data	B-Operating_System
fork	I-Operating_System
and	O
resource	B-Operating_System
fork	I-Operating_System
.	O
</s>
<s>
HFS	B-Application
Plus	I-Application
also	O
uses	O
a	O
full	O
32-bit	O
allocation	O
mapping	O
table	O
rather	O
than	O
HFS	B-Application
's	O
16	O
bits	O
,	O
improving	O
the	O
use	O
of	O
space	O
on	O
large	O
disks	O
.	O
</s>
<s>
Codenamed	O
Sequoia	O
in	O
development	O
,	O
HFS+	B-Application
was	O
introduced	O
with	O
the	O
January	O
19	O
,	O
1998	O
,	O
release	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
8.1	I-Operating_System
.	O
</s>
<s>
With	O
the	O
release	O
of	O
the	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.2.2	I-Operating_System
update	O
on	O
November	O
11	O
,	O
2002	O
,	O
Apple	O
added	O
optional	O
journaling	B-Application
features	O
to	O
HFS	B-Application
Plus	I-Application
for	O
improved	O
data	O
reliability	O
.	O
</s>
<s>
These	O
features	O
were	O
accessible	O
through	O
the	O
GUI	O
,	O
using	O
the	O
Disk	B-Application
Utility	I-Application
application	O
in	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
Server	I-Operating_System
,	O
but	O
only	O
accessible	O
through	O
the	O
command	O
line	O
in	O
the	O
standard	O
desktop	O
client	O
.	O
</s>
<s>
With	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
v10.3	I-Operating_System
,	O
all	O
HFS	B-Application
Plus	I-Application
volumes	O
on	O
all	O
Macs	O
were	O
set	O
to	O
be	O
journaled	O
by	O
default	O
.	O
</s>
<s>
Within	O
the	O
system	O
,	O
an	O
HFS	B-Application
Plus	I-Application
volume	O
with	O
a	O
journal	O
is	O
identified	O
as	O
HFSJ	B-Application
.	O
</s>
<s>
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.3	I-Operating_System
also	O
introduced	O
another	O
version	O
of	O
HFS	B-Application
Plus	I-Application
called	O
HFSX	B-Application
.	O
</s>
<s>
HFSX	B-Application
volumes	O
are	O
almost	O
identical	O
to	O
HFS	B-Application
Plus	I-Application
volumes	O
,	O
except	O
that	O
they	O
are	O
never	O
surrounded	O
by	O
the	O
HFS	B-Application
Wrapper	O
that	O
is	O
typical	O
of	O
HFS	B-Application
Plus	I-Application
volumes	O
and	O
they	O
optionally	O
support	O
case	O
sensitivity	O
for	O
file	O
and	O
folder	O
names	O
.	O
</s>
<s>
HFSX	B-Application
volumes	O
can	O
be	O
recognized	O
by	O
two	O
entries	O
in	O
the	O
Volume	O
Header	O
,	O
a	O
value	O
of	O
HX	O
in	O
the	O
signature	O
field	O
and	O
5	O
in	O
the	O
version	O
field	O
.	O
</s>
<s>
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.3	I-Operating_System
also	O
marked	O
Apple	O
's	O
adoption	O
of	O
Unicode	O
3.2	O
decomposition	O
,	O
superseding	O
the	O
Unicode	O
2.1	O
decomposition	O
used	O
previously	O
.	O
</s>
<s>
This	O
change	O
caused	O
problems	O
for	O
developers	O
writing	O
software	O
for	O
Mac	B-Device
OS	I-Device
X	I-Device
.	O
</s>
<s>
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.3	I-Operating_System
introduced	O
a	O
number	O
of	O
techniques	O
that	O
are	O
intended	O
to	O
avoid	O
fragmentating	O
files	O
in	O
HFS+	B-Application
.	O
</s>
<s>
With	O
Mac	B-Application
OS	I-Application
X	I-Application
10.4	I-Application
,	O
Apple	O
added	O
support	O
for	O
Inline	O
Attribute	O
Data	O
records	O
,	O
something	O
that	O
had	O
been	O
a	O
part	O
of	O
the	O
Mac	B-Device
OS	I-Device
X	I-Device
implementation	O
of	O
HFS	B-Application
Plus	I-Application
since	O
at	O
least	O
10.0	B-Operating_System
,	O
but	O
always	O
marked	O
as	O
"	O
reserved	O
for	O
future	O
use	O
"	O
.	O
</s>
<s>
Until	O
the	O
release	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
Server	I-Operating_System
10.4	I-Operating_System
,	O
HFS	B-Application
Plus	I-Application
supported	O
only	O
the	O
standard	O
UNIX	O
file	O
system	O
permissions	O
;	O
however	O
,	O
10.4	B-Application
introduced	O
support	O
for	O
access	O
control	O
list	O
–	O
based	O
file	O
security	O
,	O
which	O
provides	O
a	O
richer	O
mechanism	O
to	O
define	O
file	O
permissions	O
and	O
is	O
also	O
designed	O
to	O
be	O
fully	O
compatible	O
with	O
the	O
file	O
permission	O
models	O
on	O
other	O
platforms	O
such	O
as	O
Microsoft	B-Application
Windows	I-Application
XP	I-Application
and	O
Windows	B-Application
Server	I-Application
2003	I-Application
.	O
</s>
<s>
In	O
Mac	B-Device
OS	I-Device
X	I-Device
Leopard	O
10.5	O
,	O
directory	O
hard-linking	O
was	O
added	O
as	O
a	O
fundamental	O
part	O
of	O
Time	B-Operating_System
Machine	I-Operating_System
.	O
</s>
<s>
In	O
Mac	B-Device
OS	I-Device
X	I-Device
Snow	I-Device
Leopard	I-Device
10.6	B-Device
,	O
HFS+	B-Application
compression	O
was	O
added	O
using	O
Deflate	O
(	O
Zlib	O
)	O
.	O
</s>
<s>
Compressed	O
data	O
may	O
be	O
stored	O
in	O
either	O
an	O
extended	O
attribute	O
or	O
the	O
resource	B-Operating_System
fork	I-Operating_System
.	O
</s>
<s>
OS	B-Operating_System
X	I-Operating_System
10.9	O
introduced	O
two	O
new	O
algorithms	O
:	O
LZVN	B-Application
(	O
libFastCompression	O
)	O
,	O
and	O
LZFSE	B-Application
.	O
</s>
<s>
In	O
Mac	B-Application
OS	I-Application
X	I-Application
Lion	I-Application
10.7	B-Application
,	O
logical	O
volume	O
encryption	O
(	O
known	O
as	O
FileVault	O
2	O
)	O
was	O
added	O
to	O
the	O
operating	O
system	O
.	O
</s>
<s>
Apple	O
's	O
logical	O
volume	O
manager	O
is	O
known	O
as	O
Core	O
Storage	O
and	O
its	O
encryption	O
at	O
the	O
volume	O
level	O
can	O
apply	O
to	O
file	O
systems	O
other	O
than	O
HFS	B-Application
Plus	I-Application
.	O
</s>
<s>
HFS	B-Application
Plus	I-Application
volumes	O
are	O
divided	O
into	O
sectors	O
(	O
called	O
logical	O
blocks	O
in	O
HFS	B-Application
)	O
,	O
that	O
are	O
usually	O
512	O
bytes	O
in	O
size	O
.	O
</s>
<s>
HFS	B-Application
Plus	I-Application
uses	O
a	O
larger	O
value	O
to	O
address	O
allocation	O
blocks	O
than	O
HFS	B-Application
,	O
32	O
bits	O
rather	O
than	O
16	O
bits	O
;	O
this	O
means	O
it	O
can	O
access	O
4,294,967,296	O
(=	O
232	O
)	O
allocation	O
blocks	O
rather	O
than	O
the	O
65,536	O
(=	O
216	O
)	O
allocation	O
blocks	O
available	O
to	O
HFS	B-Application
.	O
</s>
<s>
For	O
example	O
,	O
on	O
a	O
1	O
GB	O
disk	O
,	O
the	O
allocation	O
block	O
size	O
under	O
HFS	B-Application
is	O
16	O
KB	O
,	O
so	O
even	O
a	O
1-byte	O
file	O
would	O
take	O
up	O
16	O
KB	O
of	O
disk	O
space	O
.	O
</s>
<s>
HFS	B-Application
Plus	I-Application
's	O
system	O
greatly	O
improves	O
space	O
utilization	O
on	O
larger	O
disks	O
as	O
a	O
result	O
.	O
</s>
<s>
File	O
and	O
folder	O
names	O
in	O
HFS	B-Application
Plus	I-Application
are	O
also	O
encoded	O
in	O
UTF-16	O
and	O
normalized	O
to	O
a	O
form	O
very	O
nearly	O
the	O
same	O
as	O
Unicode	O
Normalization	O
Form	O
D	O
(	O
NFD	O
)	O
(	O
which	O
means	O
that	O
precomposed	O
characters	O
like	O
"	O
å	O
"	O
are	O
decomposed	O
in	O
the	O
HFS+	B-Application
filename	O
and	O
therefore	O
count	O
as	O
two	O
code	O
units	O
and	O
UTF-16	O
implies	O
that	O
characters	O
from	O
outside	O
the	O
Basic	O
Multilingual	O
Plane	O
also	O
count	O
as	O
two	O
code	O
units	O
in	O
an	O
HFS+	B-Application
filename	O
)	O
.	O
</s>
<s>
HFS	B-Application
Plus	I-Application
permits	O
filenames	O
up	O
to	O
255	O
UTF-16	O
code	O
units	O
in	O
length	O
.	O
</s>
<s>
Formerly	O
,	O
HFS	B-Application
Plus	I-Application
volumes	O
were	O
embedded	O
inside	O
an	O
HFS	B-Application
standard	O
file	O
system	O
.	O
</s>
<s>
This	O
was	O
phased	O
out	O
by	O
the	O
Tiger	O
transition	O
to	O
Intel	O
Macs	O
,	O
where	O
the	O
HFS	B-Application
Plus	I-Application
file	O
system	O
was	O
not	O
embedded	O
inside	O
a	O
wrapper	O
.	O
</s>
<s>
The	O
wrapper	O
had	O
been	O
designed	O
for	O
two	O
purposes	O
;	O
it	O
allowed	O
Macintosh	O
computers	O
without	O
HFS	B-Application
Plus	I-Application
support	O
in	O
their	O
ROM	O
to	O
boot	O
HFS	B-Application
Plus	I-Application
volumes	O
and	O
it	O
also	O
was	O
designed	O
to	O
help	O
users	O
transition	O
to	O
HFS	B-Application
Plus	I-Application
by	O
including	O
a	O
minimal	O
HFS	B-Application
volume	O
with	O
a	O
read-only	O
file	O
called	O
Where_have_all_my_files_gone	O
?,	O
explaining	O
to	O
users	O
with	O
versions	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
8.0	I-Operating_System
and	O
earlier	O
without	O
HFS	B-Application
Plus	I-Application
,	O
that	O
the	O
volume	O
requires	O
a	O
system	O
with	O
HFS	B-Application
Plus	I-Application
support	O
.	O
</s>
<s>
The	O
original	O
HFS	B-Application
volume	O
contains	O
a	O
signature	O
and	O
an	O
offset	O
to	O
the	O
embedded	O
HFS	B-Application
Plus	I-Application
volume	O
within	O
its	O
volume	O
header	O
.	O
</s>
<s>
All	O
allocation	O
blocks	O
in	O
the	O
HFS	B-Application
volume	O
which	O
contain	O
the	O
embedded	O
volume	O
are	O
mapped	O
out	O
of	O
the	O
HFS	B-Application
allocation	O
file	O
as	O
bad	O
blocks	O
.	O
</s>
<s>
Notable	O
among	O
file	O
systems	O
used	O
for	O
Unix	O
systems	O
,	O
HFS	B-Application
Plus	I-Application
does	O
not	O
support	O
sparse	B-General_Concept
files	I-General_Concept
.	O
</s>
<s>
There	O
are	O
nine	O
structures	O
that	O
make	O
up	O
a	O
typical	O
HFS	B-Application
Plus	I-Application
volume	O
:	O
</s>
<s>
Sectors	O
0	O
and	O
1	O
of	O
the	O
volume	O
are	O
HFS	B-Application
boot	B-Device
blocks	I-Device
.	O
</s>
<s>
These	O
are	O
identical	O
to	O
the	O
boot	B-Device
blocks	I-Device
in	O
an	O
HFS	B-Application
volume	O
.	O
</s>
<s>
They	O
are	O
part	O
of	O
the	O
HFS	B-Application
wrapper	O
.	O
</s>
<s>
Sector	O
2	O
contains	O
the	O
Volume	O
Header	O
,	O
which	O
is	O
equivalent	O
to	O
the	O
Master	O
Directory	O
Block	O
in	O
an	O
HFS	B-Application
volume	O
.	O
</s>
<s>
The	O
Allocation	O
File	O
which	O
keeps	O
track	O
of	O
which	O
allocation	O
blocks	O
are	O
free	B-Application
and	O
which	O
are	O
in	O
use	O
.	O
</s>
<s>
It	O
is	O
similar	O
to	O
the	O
Volume	O
Bitmap	B-Data_Structure
in	O
HFS	B-Application
,	O
in	O
which	O
each	O
allocation	O
block	O
is	O
represented	O
by	O
one	O
bit	O
.	O
</s>
<s>
A	O
zero	O
means	O
the	O
block	O
is	O
free	B-Application
and	O
a	O
one	O
means	O
the	O
block	O
is	O
in	O
use	O
.	O
</s>
<s>
The	O
main	O
difference	O
with	O
the	O
HFS	B-Application
Volume	O
Bitmap	B-Data_Structure
,	O
is	O
that	O
the	O
Allocation	O
File	O
is	O
stored	O
as	O
a	O
regular	O
file	O
–	O
it	O
does	O
not	O
occupy	O
a	O
special	O
reserved	O
space	O
near	O
the	O
beginning	O
of	O
the	O
volume	O
.	O
</s>
<s>
The	O
Catalog	O
File	O
is	O
a	O
B-tree	B-Architecture
that	O
contains	O
records	O
for	O
all	O
the	O
files	O
and	O
directories	O
stored	O
in	O
the	O
volume	O
.	O
</s>
<s>
The	O
HFS	B-Application
Plus	I-Application
Catalog	O
File	O
is	O
very	O
similar	O
to	O
the	O
HFS	B-Application
Catalog	O
File	O
,	O
the	O
main	O
differences	O
being	O
records	O
are	O
larger	O
to	O
allow	O
more	O
fields	O
and	O
to	O
allow	O
for	O
those	O
fields	O
to	O
be	O
larger	O
(	O
for	O
example	O
to	O
allow	O
the	O
longer	O
255-character	O
unicode	O
file	O
names	O
in	O
HFS	B-Application
Plus	I-Application
)	O
.	O
</s>
<s>
A	O
record	O
in	O
the	O
HFS	B-Application
Catalog	O
File	O
is	O
512	O
bytes	O
in	O
size	O
;	O
a	O
record	O
in	O
the	O
HFS	B-Application
Plus	I-Application
Catalog	O
File	O
is	O
4KB	O
in	O
the	O
classic	B-Application
Mac	I-Application
OS	I-Application
and	O
8KB	O
in	O
macOS	B-Application
.	O
</s>
<s>
Fields	O
in	O
HFS	B-Application
are	O
of	O
fixed	O
size	O
,	O
while	O
in	O
HFS	B-Application
Plus	I-Application
the	O
size	O
can	O
vary	O
depending	O
on	O
the	O
actual	O
size	O
of	O
the	O
data	O
they	O
store	O
.	O
</s>
<s>
The	O
Extents	O
Overflow	O
File	O
is	O
another	O
B-tree	B-Architecture
that	O
records	O
the	O
allocation	O
blocks	O
that	O
are	O
allocated	O
to	O
each	O
file	O
as	O
extents	O
.	O
</s>
<s>
Each	O
file	O
record	O
in	O
the	O
Catalog	O
File	O
is	O
capable	O
of	O
recording	O
eight	O
extents	O
for	O
each	O
fork	B-Application
of	O
a	O
file	O
;	O
once	O
those	O
are	O
used	O
additional	O
extents	O
are	O
recorded	O
in	O
the	O
Extents	O
Overflow	O
File	O
.	O
</s>
<s>
The	O
default	O
size	O
of	O
an	O
extent	O
record	O
in	O
the	O
classic	B-Application
Mac	I-Application
OS	I-Application
is	O
1	O
KB	O
and	O
4	O
KB	O
in	O
macOS	B-Application
.	O
</s>
<s>
The	O
Attributes	O
File	O
is	O
a	O
new	O
B-tree	B-Architecture
in	O
HFS	B-Application
Plus	I-Application
that	O
does	O
not	O
have	O
a	O
corresponding	O
structure	O
in	O
HFS	B-Application
.	O
</s>
<s>
The	O
Attributes	O
File	O
can	O
store	O
three	O
different	O
types	O
of	O
4	O
KB	O
records	O
:	O
Inline	O
Data	O
Attribute	O
records	O
,	O
Fork	B-Application
Data	O
Attribute	O
records	O
and	O
Extension	O
Attribute	O
records	O
.	O
</s>
<s>
Fork	B-Application
Data	O
Attribute	O
records	O
contain	O
references	O
to	O
a	O
maximum	O
of	O
eight	O
extents	O
that	O
can	O
hold	O
larger	O
attributes	O
.	O
</s>
<s>
Extension	O
Attributes	O
are	O
used	O
to	O
extend	O
a	O
Fork	B-Application
Data	O
Attribute	O
record	O
when	O
its	O
eight	O
extent	O
records	O
are	O
already	O
used	O
.	O
</s>
<s>
The	O
Startup	O
File	O
is	O
designed	O
for	O
non-Mac	O
OS	O
systems	O
that	O
lack	O
HFS	B-Application
or	O
HFS	B-Application
Plus	I-Application
support	O
.	O
</s>
<s>
It	O
is	O
similar	O
to	O
the	O
Boot	B-Device
Blocks	I-Device
of	O
an	O
HFS	B-Application
volume	O
.	O
</s>
<s>
The	O
second-to-last	O
sector	O
contains	O
the	O
Alternate	O
Volume	O
Header	O
,	O
which	O
is	O
equivalent	O
to	O
the	O
Alternate	O
Master	O
Directory	O
Block	O
of	O
HFS	B-Application
.	O
</s>
<s>
HFS	B-Application
Plus	I-Application
lacks	O
several	O
features	O
considered	O
staples	O
of	O
modern	O
file	O
systems	O
like	O
ZFS	B-Application
and	O
NTFS	B-Application
.	O
</s>
<s>
Data	O
checksums	B-Algorithm
are	O
the	O
most	O
routinely	O
cited	O
missing	O
feature	O
.	O
</s>
<s>
Besides	O
checksumming	O
,	O
features	O
of	O
modern	O
file	O
systems	O
that	O
HFS+	B-Application
lacks	O
include	O
:	O
</s>
<s>
HFS	B-Application
Plus	I-Application
was	O
not	O
designed	O
for	O
Unix-like	B-Operating_System
systems	I-Operating_System
,	O
so	O
features	O
such	O
as	O
file	O
system	O
permissions	O
and	O
hard	B-Application
links	I-Application
had	O
to	O
be	O
retrofitted	O
when	O
Apple	O
moved	O
to	O
Mac	B-Device
OS	I-Device
X	I-Device
.	O
</s>
<s>
The	O
Linux	B-Operating_System
kernel	I-Operating_System
includes	O
the	O
hfsplus	B-Application
module	O
for	O
mounting	O
HFS+	B-Application
filesystems	O
read-write	O
.	O
</s>
<s>
HFS+	B-Application
fsck	B-Device
and	O
mkfs	B-Device
have	O
been	O
ported	O
to	O
Linux	B-Application
and	O
are	O
part	O
of	O
the	O
hfsprogs	O
package	O
.	O
</s>
<s>
In	O
2009	O
,	O
these	O
drivers	O
were	O
diagnosed	O
to	O
be	O
corrupting	O
HFS+	B-Application
drives	O
with	O
a	O
capacity	O
greater	O
than	O
2TB	O
.	O
</s>
<s>
Consequently	O
,	O
Linux	B-Application
distributions	O
such	O
as	O
Debian	O
and	O
Ubuntu	B-Operating_System
stopped	O
allowing	O
mounting	O
of	O
HFS+	B-Application
drives	O
or	O
partitions	O
greater	O
than	O
2TB	O
.	O
</s>
<s>
Under	O
Linux	B-Application
's	O
current	O
HFS+	B-Application
driver	O
,	O
journaling	B-Application
must	O
be	O
disabled	O
in	O
order	O
to	O
write	O
data	O
safely	O
onto	O
an	O
HFS+	B-Application
partition	O
.	O
</s>
<s>
Provided	O
the	O
partition	O
is	O
n't	O
being	O
used	O
by	O
Apple	O
's	O
Time	B-Operating_System
Machine	I-Operating_System
software	O
,	O
journaling	B-Application
can	O
be	O
disabled	O
under	O
macOS	B-Application
:	O
Using	O
Disk	B-Application
Utility	I-Application
in	O
OS	B-Operating_System
X	I-Operating_System
Yosemite	O
,	O
the	O
user	O
may	O
hold	O
Alt/Option	O
and	O
click	O
"	O
Disable	O
Journaling	B-Application
"	O
on	O
the	O
File	O
menu	O
,	O
having	O
first	O
selected	O
a	O
mounted	O
partition	O
.	O
</s>
<s>
An	O
HFS+	B-Application
partition	O
with	O
journaling	B-Application
enabled	O
may	O
be	O
forcibly	O
mounted	O
with	O
write	O
access	O
under	O
Linux	B-Application
,	O
but	O
this	O
is	O
unsupported	O
and	O
unwise	O
.	O
</s>
<s>
A	O
Google	B-Application
Summer	I-Application
of	I-Application
Code	I-Application
project	O
to	O
implement	O
write	O
support	O
to	O
journaled	O
HFS+	B-Application
was	O
accepted	O
by	O
the	O
Linux	B-Application
Foundation	O
in	O
2011	O
but	O
was	O
not	O
completed	O
at	O
that	O
time	O
and	O
is	O
still	O
a	O
work	O
in	O
progress	O
.	O
</s>
<s>
Progress	O
and	O
improvements	O
to	O
the	O
HFS+	B-Application
driver	O
,	O
including	O
some	O
updates	O
to	O
journaling	B-Application
support	O
,	O
are	O
posted	O
on	O
the	O
linux-fsdevel	O
mailing	O
list	O
from	O
time	O
to	O
time	O
.	O
</s>
<s>
,	O
Paragon	O
Software	O
Group	O
provided	O
kernel	B-Operating_System
drivers	O
that	O
allow	O
full	O
read-write	O
access	O
to	O
HFS+	B-Application
journaled	O
volumes	O
.	O
</s>
<s>
The	O
product	O
is	O
a	O
proprietary	O
implementation	O
of	O
HFS+	B-Application
based	O
on	O
Paragon	O
's	O
proprietary	O
UFSD	O
library	O
.	O
</s>
<s>
There	O
are	O
both	O
free	B-Application
and	O
paid	O
editions	O
of	O
the	O
driver	O
,	O
and	O
they	O
include	O
a	O
utility	O
for	O
checking	O
and	O
repairing	O
HFS+	B-Application
volumes	O
.	O
</s>
<s>
According	O
to	O
the	O
online	O
documentation	O
(	O
free	B-Application
version	O
or	O
the	O
paid	O
edition	O
)	O
,	O
both	O
the	O
free	B-Application
edition	O
and	O
the	O
paid	O
edition	O
currently	O
support	O
Linux	B-Operating_System
kernels	I-Operating_System
from	O
2.6.36	O
up	O
to	O
4.12.x	O
.	O
</s>
<s>
Ubuntu	B-Operating_System
,	O
Debian	O
,	O
Fedora	O
Linux	B-Application
,	O
Rocky	O
Linux	B-Application
,	O
Red	O
Hat	O
Enterprise	O
Linux	B-Application
,	O
OpenSUSE	B-Operating_System
and	O
CentOS	O
are	O
the	O
only	O
Linux	B-Application
distributions	O
officially	O
supported	O
.	O
</s>
<s>
As	O
of	O
May	O
2012	O
,	O
Apple	O
has	O
only	O
released	O
read-only	O
HFS+	B-Application
drivers	O
for	O
Windows	B-Application
XP	I-Application
,	O
Windows	O
Vista	O
,	O
and	O
Windows	O
7	O
as	O
part	O
of	O
the	O
Boot	B-Application
Camp	I-Application
software	O
in	O
Mac	B-Device
OS	I-Device
X	I-Device
10.6	I-Device
.	O
</s>
<s>
This	O
means	O
users	O
on	O
these	O
systems	O
can	O
read	O
data	O
on	O
the	O
HFS+	B-Application
drive	O
,	O
but	O
not	O
write	O
to	O
them	O
.	O
</s>
<s>
Microsoft	O
has	O
created	O
an	O
HFS+	B-Application
driver	O
for	O
the	O
Xbox	O
360	O
mainly	O
for	O
the	O
purpose	O
of	O
reading	O
HFS+	B-Application
-formatted	O
iPods	B-Device
.	O
</s>
<s>
A	O
free	B-Application
and	O
opensource	O
software	O
–	O
jHFSplus	O
,	O
based	O
on	O
HFSExplorer	O
and	O
jpfm	O
–	O
can	O
be	O
used	O
to	O
mount	O
hfs/hfs	O
+	O
partitions	O
as	O
read-only	O
virtual	O
folders	O
.	O
</s>
<s>
A	O
freeware	O
plugin	O
for	O
Total	B-Language
Commander	I-Language
exists	O
,	O
that	O
can	O
read	O
,	O
among	O
others	O
,	O
HFS	B-Application
and	O
HFS+	B-Application
filesystems	O
.	O
</s>
<s>
DiskInternals	O
Linux	B-Application
Reader	O
can	O
be	O
used	O
to	O
extract/save	O
folders/files	O
out	O
of	O
HFS	B-Application
and	O
HFS+	B-Application
Hard	O
Drives/Partitions	O
.	O
</s>
<s>
A	O
commercial	O
product	O
,	O
MacDrive	O
,	O
is	O
also	O
available	O
for	O
mounting	O
HFS	B-Application
and	O
HFS+	B-Application
drives	O
,	O
optical	O
discs	O
,	O
and	O
other	O
media	O
in	O
Windows	O
Explorer	O
,	O
and	O
allows	O
both	O
reading	O
and	O
writing	O
to	O
the	O
volume	O
,	O
as	O
well	O
as	O
repairing	O
and	O
formatting	O
Mac	O
disks	O
.	O
</s>
<s>
A	O
commercial	O
product	O
,	O
Paragon	O
's	O
HFS+	B-Application
for	O
Windows	O
allows	O
full	O
read	O
and	O
write	O
and	O
disk	O
management	O
from	O
all	O
versions	O
of	O
Windows	O
from	O
Windows	B-Application
XP	I-Application
to	O
Windows	O
Server	O
2008	O
.	O
</s>
<s>
A	O
free	B-Application
(	O
GPL	B-License
)	O
alternative	O
is	O
HFSExplorer	O
written	O
by	O
Erik	O
Larsson	O
.	O
</s>
<s>
HFSExplorer	O
is	O
a	O
Java	O
application	O
for	O
viewing	O
and	O
extracting	O
files	O
from	O
an	O
HFS+	B-Application
volume	O
(	O
Mac	B-Application
OS	I-Application
Extended	I-Application
)	O
or	O
an	O
HFSX	B-Application
volume	O
(	O
Mac	B-Application
OS	I-Application
Extended	I-Application
,	O
Case-sensitive	O
)	O
.	O
</s>
<s>
The	O
volume	O
can	O
be	O
located	O
either	O
on	O
a	O
physical	O
disk	O
,	O
in	O
various	O
Apple	B-Operating_System
disk	I-Operating_System
image	I-Operating_System
and	O
sparse	B-Operating_System
disk	I-Operating_System
image	I-Operating_System
formats	I-Operating_System
,	O
or	O
a	O
raw	O
file	O
system	O
dump	O
.	O
</s>
<s>
However	O
,	O
HFSExplorer	O
is	O
a	O
read-only	O
solution	O
;	O
it	O
cannot	O
write	O
to	O
HFS-formatted	O
volumes	O
.	O
</s>
