<s>
The	O
VERITAS	B-Application
File	I-Application
System	I-Application
(	O
or	O
VxFS	B-Application
;	O
called	O
JFS	B-Application
and	O
OnlineJFS	O
in	O
HP-UX	B-Application
)	O
is	O
an	O
extent-based	O
file	B-Application
system	I-Application
.	O
</s>
<s>
Through	O
an	O
OEM	O
agreement	O
,	O
VxFS	B-Application
is	O
used	O
as	O
the	O
primary	O
filesystem	B-Application
of	O
the	O
HP-UX	B-Application
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
With	O
on-line	O
defragmentation	B-Application
and	O
resize	O
support	O
turned	O
on	O
via	O
license	O
,	O
it	O
is	O
known	O
as	O
OnlineJFS	O
.	O
</s>
<s>
It	O
is	O
also	O
supported	O
on	O
AIX	B-Application
,	O
Linux	B-Application
,	O
Solaris	B-Application
,	O
OpenSolaris	B-Operating_System
,	O
SINIX/Reliant	O
UNIX	O
,	O
UnixWare	B-Operating_System
and	O
SCO	B-Operating_System
OpenServer	I-Operating_System
.	O
</s>
<s>
VxFS	B-Application
was	O
originally	O
developed	O
for	O
T	O
's	O
Unix	O
System	O
Laboratories	O
.	O
</s>
<s>
VxFS	B-Application
is	O
packaged	O
as	O
a	O
part	O
of	O
the	O
Veritas	B-Application
Storage	I-Application
Foundation	I-Application
(	O
which	O
also	O
includes	O
Veritas	B-Application
Volume	I-Application
Manager	I-Application
)	O
.	O
</s>
<s>
According	O
to	O
the	O
vendor	O
,	O
it	O
was	O
the	O
first	O
commercial	O
journaling	B-Application
file	I-Application
system	I-Application
.	O
</s>
<s>
That	O
claim	O
can	O
be	O
taken	O
in	O
two	O
ways	O
,	O
i.e.	O
,	O
the	O
first	O
implementation	O
of	O
a	O
journaling	B-Application
file	I-Application
system	I-Application
in	O
a	O
commercial	O
context	O
,	O
or	O
the	O
first	O
file	B-Application
system	I-Application
available	O
as	O
an	O
unbundled	O
product	O
.	O
</s>
<s>
Dan	O
Koren	O
is	O
cited	O
as	O
one	O
of	O
the	O
original	O
developers	O
of	O
VxFS	B-Application
.	O
</s>
<s>
He	O
notes	O
in	O
a	O
mailing	O
list	O
that	O
they	O
"	O
finished	O
release	O
1.0	O
one	O
year	O
or	O
so	O
later	O
"	O
after	O
starting	O
development	O
of	O
VxFS	B-Application
under	O
a	O
contract	O
with	O
AT&T	O
Corporation	O
in	O
1990	O
.	O
</s>
<s>
As	O
the	O
internet	O
was	O
not	O
widely	O
available	O
in	O
the	O
early	O
1990s	O
,	O
getting	O
a	O
new	O
file	B-Application
system	I-Application
deployed	O
for	O
Unix-like	O
operating	B-General_Concept
systems	I-General_Concept
was	O
more	O
difficult	O
,	O
so	O
the	O
one	O
-	O
to	O
two-year	O
delay	O
in	O
the	O
release	O
and	O
commercialization	O
of	O
this	O
file	B-Application
system	I-Application
was	O
not	O
unusual	O
.	O
</s>
<s>
The	O
on-disk	O
layout	O
of	O
VxFS	B-Application
is	O
versioned	O
and	O
upgradeable	O
while	O
the	O
file	B-Application
system	I-Application
is	O
mounted	O
.	O
</s>
<s>
This	O
file	B-Application
system	I-Application
has	O
gone	O
through	O
ten	O
versions	O
.	O
</s>
<s>
Layouts	O
1-3	O
stopped	O
being	O
supported	O
in	O
VxFS	B-Application
4.0	O
.	O
</s>
<s>
Version	O
4	O
added	O
support	O
for	O
storage	O
checkpoints	O
and	O
for	O
Veritas	B-Application
Cluster	I-Application
File	I-Application
System	I-Application
.	O
</s>
<s>
Version	O
4	O
was	O
released	O
in	O
VxFS	B-Application
3.2.1	O
.	O
</s>
<s>
Layout	O
version	O
4	O
is	O
no	O
longer	O
supported	O
under	O
VxFS	B-Application
5.1	O
.	O
</s>
<s>
Version	O
5	O
started	O
support	O
for	O
file	B-Application
systems	I-Application
up	O
to	O
32	O
terabytes	O
(	O
)	O
in	O
size	O
.	O
</s>
<s>
Version	O
5	O
was	O
introduced	O
in	O
VxFS	B-Application
3.5	O
and	O
is	O
no	O
longer	O
supported	O
under	O
VxFS	B-Application
5.1	O
.	O
</s>
<s>
Version	O
6	O
added	O
support	O
for	O
file	B-Application
systems	I-Application
and	O
files	O
up	O
to	O
8	O
exabytes	O
(	O
)	O
in	O
size	O
.	O
</s>
<s>
Version	O
6	O
also	O
introduced	O
support	O
for	O
named	B-Application
streams/resource	I-Application
forks	I-Application
,	O
for	O
multiple	O
underlying	O
volumes	O
,	O
and	O
for	O
file	B-Application
change	I-Application
logs	I-Application
.	O
</s>
<s>
Version	O
6	O
was	O
introduced	O
in	O
VxFS	B-Application
4.0	O
.	O
</s>
<s>
Dynamic	O
Storage	O
Tiering	O
allows	O
root	O
users	O
to	O
move	O
files	O
among	O
different	O
volumes	O
,	O
allocate	O
files	O
to	O
different	O
volumes	O
at	O
file	O
creation	O
time	O
based	O
on	O
policy	O
,	O
and	O
independently	O
recover	O
volumes	O
,	O
without	O
altering	O
the	O
namespace	O
of	O
the	O
file	B-Application
system	I-Application
.	O
</s>
<s>
Version	O
7	O
was	O
introduced	O
in	O
VxFS	B-Application
5.0	O
.	O
</s>
<s>
Version	O
8	O
enables	O
support	O
for	O
file-level	O
snapshots	O
and	O
shared	O
extents	B-Application
.	O
</s>
<s>
Version	O
8	O
was	O
introduced	O
in	O
VxFS	B-Application
5.1	O
.	O
</s>
<s>
Version	O
9	O
was	O
introduced	O
in	O
VxFS	B-Application
6.0	O
.	O
</s>
<s>
Version	O
10	O
was	O
introduced	O
in	O
VxFS	B-Application
6.1	O
.	O
</s>
<s>
VxFS	B-Application
file	B-Application
system	I-Application
can	O
run	O
in	O
single	O
instance	O
mode	O
or	O
in	O
a	O
parallel	O
access	O
/	O
cluster	O
mode	O
.	O
</s>
<s>
The	O
parallel	O
mode	O
allows	O
for	O
multiple	O
servers	O
(	O
also	O
known	O
as	O
cluster	O
nodes	O
)	O
to	O
simultaneously	O
access	O
the	O
same	O
file	B-Application
system	I-Application
.	O
</s>
<s>
When	O
run	O
in	O
this	O
mode	O
,	O
VxFS	B-Application
is	O
referred	O
to	O
as	O
Veritas	B-Application
Cluster	I-Application
File	I-Application
System	I-Application
.	O
</s>
<s>
The	O
Cluster	O
File	B-Application
System	I-Application
provides	O
cache	O
coherency	O
and	O
POSIX	O
compliance	O
across	O
nodes	O
,	O
so	O
that	O
data	O
changes	O
are	O
atomically	O
seen	O
by	O
all	O
cluster	O
nodes	O
simultaneously	O
.	O
</s>
<s>
Because	O
Cluster	O
File	B-Application
System	I-Application
shares	O
the	O
same	O
binaries	O
and	O
same	O
on-disk	O
layout	O
as	O
single	O
instance	O
VxFS	B-Application
,	O
moving	O
between	O
cluster	O
and	O
single	O
instance	O
mode	O
is	O
straightforward	O
.	O
</s>
