<s>
The	O
compressed	O
loop	B-Application
device	I-Application
(	O
cloop	B-Application
)	O
is	O
a	O
module	B-Application
for	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
.	O
</s>
<s>
It	O
is	O
not	O
a	O
compressed	O
file	B-Application
system	I-Application
:	O
cloop	B-Application
is	O
mostly	O
used	O
as	O
a	O
convenient	O
way	O
to	O
compress	O
conventional	O
file	B-Application
systems	I-Application
onto	O
Live	O
CDs	O
.	O
</s>
<s>
Cloop	B-Application
was	O
originally	O
written	O
for	O
the	O
Levanta	O
Bootable	O
Business	O
Card	O
by	O
Rusty	O
Russell	O
,	O
but	O
is	O
now	O
maintained	O
by	O
Klaus	O
Knopper	O
,	O
the	O
author	O
of	O
Knoppix	O
.	O
</s>
<s>
The	O
Knoppix	O
cloop	B-Application
image	O
,	O
for	O
example	O
,	O
is	O
700	O
MB	O
compressed	O
and	O
around	O
1.8	O
GB	O
uncompressed	O
.	O
</s>
<s>
cloop	B-Application
images	O
contain	O
:	O
</s>
<s>
Apple	O
uses	O
a	O
similar	O
file	O
format	O
in	O
the	O
compressed	O
variant	O
of	O
its	O
DMG	B-Operating_System
disk	O
images	O
.	O
</s>
<s>
The	O
design	O
of	O
the	O
cloop	B-Application
driver	O
requires	O
that	O
compressed	O
blocks	O
be	O
read	O
whole	O
from	O
disk	O
.	O
</s>
<s>
This	O
makes	O
cloop	B-Application
access	O
inherently	O
slower	O
when	O
there	O
are	O
many	O
scattered	O
reads	O
,	O
which	O
can	O
happen	O
if	O
the	O
system	O
is	O
low	O
on	O
memory	O
or	O
when	O
a	O
large	O
program	O
with	O
many	O
shared	O
libraries	O
is	O
starting	O
.	O
</s>
<s>
reiserfs	B-Application
,	O
btrfs	B-Operating_System
)	O
,	O
especially	O
for	O
small	O
files	O
.	O
</s>
<s>
Some	O
performance	O
tests	O
related	O
to	O
cloop	B-Application
have	O
been	O
conducted	O
.	O
</s>
