<s>
Xiafs	B-Application
was	O
a	O
file	O
system	O
for	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
which	O
was	O
conceived	O
and	O
developed	O
by	O
Frank	O
Xia	O
and	O
was	O
based	O
on	O
the	O
MINIX	B-Application
file	I-Application
system	I-Application
.	O
</s>
<s>
Linux	B-Operating_System
originally	O
used	O
the	O
MINIX	B-Application
file	I-Application
system	I-Application
,	O
but	O
it	O
had	O
a	O
number	O
of	O
limitations	O
.	O
</s>
<s>
To	O
replace	O
the	O
MINIX	B-Application
file	I-Application
system	I-Application
,	O
the	O
extended	B-Application
file	I-Application
system	I-Application
(	O
or	O
ext	B-Application
)	O
was	O
developed	O
.	O
</s>
<s>
However	O
,	O
ext	B-Application
retained	O
some	O
problems	O
such	O
as	O
poor	O
performance	O
and	O
the	O
lack	O
of	O
some	O
date	O
stamps	O
.	O
</s>
<s>
Two	O
contenders	O
for	O
replacing	O
ext	B-Application
were	O
quickly	O
developed	O
:	O
ext2	B-Application
and	O
Xiafs	B-Application
.	O
</s>
<s>
The	O
two	O
file	O
systems	O
were	O
included	O
in	O
the	O
standard	O
kernel	B-Operating_System
in	O
December	O
1993	O
(	O
Linux	B-Operating_System
0.99.15	O
)	O
.	O
</s>
<s>
ext2	B-Application
and	O
Xiafs	B-Application
had	O
the	O
same	O
goal	O
:	O
To	O
offer	O
good	O
performance	O
,	O
reasonable	O
limitations	O
,	O
and	O
fixing	O
the	O
flaws	O
of	O
ext	B-Application
.	O
</s>
<s>
Initially	O
,	O
Xiafs	B-Application
was	O
more	O
stable	O
than	O
ext2	B-Application
,	O
but	O
being	O
a	O
fairly	O
minimalistic	O
modification	O
of	O
the	O
MINIX	B-Application
file	I-Application
system	I-Application
,	O
it	O
was	O
not	O
very	O
well	O
suited	O
for	O
future	O
extension	O
.	O
</s>
<s>
The	O
end	O
result	O
was	O
that	O
Xiafs	B-Application
changed	O
very	O
little	O
while	O
ext2	B-Application
evolved	O
considerably	O
,	O
rapidly	O
improving	O
stability	O
and	O
performance	O
,	O
and	O
adding	O
extensions	O
.	O
</s>
<s>
ext2	B-Application
,	O
after	O
some	O
shakedown	O
time	O
,	O
quickly	O
became	O
the	O
standard	O
file	O
system	O
of	O
Linux	B-Operating_System
.	O
</s>
<s>
Since	O
then	O
,	O
ext2	B-Application
has	O
developed	O
into	O
a	O
very	O
mature	O
and	O
robust	O
file	O
system	O
.	O
</s>
<s>
Xiafs	B-Application
and	O
the	O
original	O
ext	B-Application
were	O
removed	O
from	O
Linux	B-Operating_System
version	O
2.1.21	O
,	O
as	O
they	O
were	O
no	O
longer	O
in	O
use	O
and	O
were	O
not	O
maintained	O
.	O
</s>
<s>
ext2	B-Application
,	O
ext3	B-Application
,	O
and	O
their	O
successor	O
ext4	B-Application
are	O
in	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
.	O
</s>
<s>
As	O
an	O
exercise	O
in	O
computer	O
history	O
and	O
as	O
a	O
file	O
system	O
tutorial	O
,	O
Xiafs	B-Application
was	O
ported	O
to	O
modern	O
Linux	B-Operating_System
in	O
2013	O
.	O
</s>
<s>
Xiafs	B-Application
was	O
less	O
powerful	O
and	O
offered	O
less	O
functionality	O
than	O
ext2	B-Application
.	O
</s>
<s>
While	O
this	O
was	O
an	O
improvement	O
over	O
ext	B-Application
,	O
it	O
did	O
not	O
measure	O
up	O
to	O
ext2	B-Application
.	O
</s>
<s>
Xiafs	B-Application
used	O
less	O
disk	O
space	O
for	O
its	O
control	O
structures	O
and	O
it	O
had	O
greater	O
stability	O
at	O
that	O
time	O
.	O
</s>
