<s>
In	O
computing	O
,	O
the	O
File	B-Application
Alteration	I-Application
Monitor	I-Application
,	O
also	O
known	O
as	O
FAM	O
and	O
sgi_fam	O
,	O
provides	O
a	O
subsystem	O
developed	O
by	O
Silicon	O
Graphics	O
for	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
The	O
FAM	O
subsystem	O
allows	O
applications	B-Application
to	O
watch	O
certain	O
files	B-Operating_System
and	O
be	O
notified	O
when	O
they	O
are	O
modified	O
.	O
</s>
<s>
This	O
greatly	O
aids	O
the	O
applications	B-Application
,	O
because	O
before	O
FAM	O
existed	O
,	O
such	O
applications	B-Application
would	O
have	O
to	O
read	O
the	O
disk	B-Device
repeatedly	O
to	O
detect	O
any	O
changes	O
,	O
which	O
resulted	O
in	O
high	O
disk	B-Device
and	O
CPU	B-General_Concept
usage	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
file	B-Application
manager	I-Application
application	O
can	O
detect	O
if	O
some	O
file	O
has	O
changed	O
and	O
can	O
then	O
update	O
a	O
displayed	O
icon	O
and/or	O
filename	O
.	O
</s>
<s>
famd	B-Application
—	O
the	O
FAM	O
Daemon	O
,	O
which	O
provides	O
notifications	O
and	O
listens	O
for	O
requests	O
.	O
</s>
<s>
Although	O
FAM	O
may	O
seem	O
unnecessary	O
now	O
that	O
many	O
newer	O
kernels	O
include	O
built-in	O
notification	O
support	O
(	O
inotify	B-Application
in	O
Linux	B-Application
,	O
for	O
example	O
)	O
,	O
using	O
FAM	O
provides	O
two	O
benefits	O
:	O
</s>
<s>
Consistently	O
using	O
FAM	O
enables	O
applications	B-Application
to	O
work	O
on	O
a	O
greater	O
variety	O
of	O
platforms	O
,	O
agnostic	O
of	O
the	O
kernel	O
.	O
</s>
<s>
FAM	O
is	O
network-aware	O
,	O
and	O
if	O
a	O
monitor	O
is	O
started	O
on	O
an	O
NFS	B-Protocol
share	O
,	O
it	O
will	O
attempt	O
to	O
contact	O
a	O
FAM	O
server	O
on	O
the	O
NFS	B-Protocol
server	O
and	O
have	O
it	O
monitor	O
the	O
file	O
locally	O
,	O
which	O
is	O
more	O
efficient	O
.	O
</s>
<s>
The	O
main	O
problem	O
with	O
FAM	O
is	O
that	O
during	O
the	O
creation	O
of	O
a	O
large	O
number	O
of	O
files	B-Operating_System
(	O
for	O
example	O
during	O
the	O
first	O
login	O
in	O
a	O
desktop	O
environment	O
)	O
it	O
slows	O
down	O
the	O
entire	O
system	O
,	O
using	O
many	O
CPU	B-General_Concept
cycles	O
.	O
</s>
