<s>
z/OS	B-Application
File	I-Application
System	I-Application
(	O
zFS	B-Application
)	O
(	O
official	O
name	O
:	O
z/OS	B-Application
®	O
Distributed	O
File	O
Service	O
zSeries®	O
File	O
System	O
)	O
is	O
a	O
POSIX-style	O
hierarchical	B-Application
file	I-Application
system	I-Application
for	O
IBM	O
's	O
z/OS	B-Application
operating	O
system	O
for	O
z	B-Device
System	I-Device
mainframes	O
,	O
a	O
successor	O
to	O
that	O
operating	O
system	O
's	O
HFS	B-Application
.	O
</s>
<s>
zFS	B-Application
technology	O
was	O
first	O
released	O
in	O
1995	O
as	O
the	O
Local	B-Application
File	I-Application
System	I-Application
,	O
a	O
lower	O
layer	O
of	O
the	O
DCE	B-Protocol
Distributed	I-Protocol
File	I-Protocol
System	I-Protocol
.	O
</s>
<s>
It	O
was	O
available	O
on	O
MVS/ESA	O
V5R2.2	O
and	O
all	O
OS/390	B-Application
releases	O
.	O
</s>
<s>
DFS/LFS	O
was	O
provided	O
as	O
a	O
part	O
of	O
the	O
DCE	B-Operating_System
feature	O
,	O
not	O
part	O
of	O
the	O
base	O
operating	O
system	O
.	O
</s>
<s>
As	O
a	O
separate	O
feature	O
(	O
outside	O
the	O
DCE	B-Operating_System
feature	O
)	O
,	O
zFS	B-Application
was	O
initially	O
released	O
for	O
z/OS	B-Application
as	O
PTFs	O
(	O
patches	O
)	O
for	O
z/OS	B-Application
1.2	O
,	O
with	O
backports	O
available	O
for	O
z/OS	B-Application
1.1	O
and	O
OS/390	B-Application
2.10	O
.	O
</s>
<s>
Beginning	O
with	O
z/OS	B-Application
1.3	O
,	O
zFS	B-Application
is	O
included	O
as	O
a	O
standard	O
feature	O
and	O
is	O
being	O
actively	O
developed	O
.	O
</s>
