<s>
Scratch	B-General_Concept
space	I-General_Concept
is	O
space	O
on	O
the	O
hard	B-Device
disk	I-Device
drive	I-Device
that	O
is	O
dedicated	O
for	O
storage	O
of	O
temporary	O
user	O
data	O
.	O
</s>
<s>
It	O
is	O
unreliable	O
by	O
intention	O
and	O
has	O
no	O
back	B-Protocol
up	I-Protocol
.	O
</s>
<s>
Scratch	B-General_Concept
disks	I-General_Concept
may	O
occasionally	O
be	O
set	O
to	O
erase	O
all	O
data	O
at	O
regular	O
intervals	O
so	O
that	O
the	O
disk	O
space	O
is	O
left	O
free	O
for	O
future	O
use	O
.	O
</s>
<s>
The	O
management	O
of	O
scratch	B-General_Concept
disk	I-General_Concept
space	O
is	O
typically	O
dynamic	O
,	O
occurring	O
when	O
needed	O
.	O
</s>
<s>
Scratch	B-General_Concept
space	I-General_Concept
is	O
commonly	O
used	O
in	O
scientific	O
computing	O
workstations	O
,	O
and	O
in	O
graphic	O
design	O
programs	O
such	O
as	O
Adobe	B-Operating_System
Photoshop	I-Operating_System
.	O
</s>
<s>
It	O
is	O
used	O
when	O
programs	O
need	O
to	O
use	O
more	O
data	O
than	O
can	O
be	O
stored	O
in	O
system	O
RAM	B-Architecture
.	O
</s>
<s>
A	O
common	O
error	O
in	O
that	O
program	O
is	O
"	O
scratch	B-General_Concept
disks	I-General_Concept
full	O
"	O
,	O
which	O
occurs	O
when	O
one	O
has	O
the	O
scratch	B-General_Concept
disks	I-General_Concept
configured	O
to	O
be	O
on	O
the	O
boot	O
drive	O
.	O
</s>
<s>
Many	O
computer	O
users	O
gradually	O
fill	O
up	O
their	O
primary	O
hard	B-Device
drive	I-Device
with	O
permanent	O
data	O
,	O
slowly	O
reducing	O
the	O
amount	O
of	O
space	O
the	O
scratch	B-General_Concept
disk	I-General_Concept
may	O
take	O
up	O
.	O
</s>
<s>
Partitioning	O
off	O
a	O
significant	O
fraction	O
of	O
the	O
boot	O
hard	B-Device
drive	I-Device
and	O
leaving	O
that	O
space	O
empty	O
will	O
ensure	O
a	O
reliable	O
scratch	B-General_Concept
disk	I-General_Concept
.	O
</s>
<s>
Hard	B-Device
drive	I-Device
space	O
,	O
on	O
a	O
per-gigabyte	O
basis	O
,	O
is	O
far	O
cheaper	O
than	O
RAM	B-Architecture
,	O
though	O
performs	O
far	O
slower	O
.	O
</s>
<s>
Though	O
dedicating	O
a	O
separate	O
physical	O
drive	O
from	O
the	O
main	O
operating	O
system	O
and	O
software	O
can	O
improve	O
performance	O
,	O
a	O
scratch	B-General_Concept
disk	I-General_Concept
will	O
not	O
match	O
RAM	B-Architecture
for	O
speed	O
.	O
</s>
