<s>
In	O
computer	B-General_Concept
science	I-General_Concept
,	O
trace-based	B-Operating_System
simulation	I-Operating_System
refers	O
to	O
system	B-Application
simulation	I-Application
performed	O
by	O
looking	O
at	O
traces	O
of	O
program	O
execution	O
or	O
system	O
component	O
access	O
with	O
the	O
purpose	O
of	O
performance	O
prediction	O
.	O
</s>
<s>
Trace-based	B-Operating_System
simulation	I-Operating_System
may	O
be	O
used	O
in	O
a	O
variety	O
of	O
applications	O
,	O
from	O
the	O
analysis	O
of	O
solid	B-Device
state	I-Device
disks	I-Device
to	O
the	O
message	B-Architecture
passing	I-Architecture
performance	O
on	O
very	O
large	O
computer	B-Architecture
clusters	I-Architecture
.	O
</s>
<s>
For	O
instance	O
,	O
in	O
the	O
case	O
of	O
large	O
computer	B-Architecture
cluster	I-Architecture
design	O
,	O
the	O
execution	O
takes	O
place	O
on	O
a	O
small	O
number	O
of	O
nodes	O
,	O
and	O
traces	O
are	O
left	O
in	O
log	O
files	O
.	O
</s>
