<s>
The	O
IBM	B-Application
SAN	I-Application
File	I-Application
System	I-Application
is	O
a	O
distributed	O
,	O
heterogeneous	O
file	B-Application
system	I-Application
developed	O
by	O
IBM	O
to	O
be	O
used	O
in	O
storage	O
area	O
networks	O
.	O
</s>
<s>
There	O
are	O
many	O
virtualization	O
features	O
included	O
,	O
such	O
as	O
allowing	O
heterogeneous	O
operating	B-General_Concept
systems	I-General_Concept
to	O
access	O
the	O
same	O
data	O
and	O
file	O
spaces	O
.	O
</s>
<s>
Write-in-place	O
b-trees	O
were	O
used	O
as	O
in	O
the	O
DB2	O
database	O
,	O
later	O
on	O
better	O
known	O
as	O
core	O
of	O
the	O
btrfs	B-Operating_System
.	O
</s>
<s>
IBM	O
discontinued	O
selling	O
the	O
SAN	O
File	B-Application
System	I-Application
in	O
April	O
2007	O
.	O
</s>
<s>
It	O
has	O
been	O
replaced	O
by	O
IBM	B-Application
General	I-Application
Parallel	I-Application
File	I-Application
System	I-Application
(	O
GPFS	B-Application
)	O
.	O
</s>
