<s>
Core	B-Operating_System
Storage	I-Operating_System
is	O
a	O
logical	B-Application
volume	I-Application
management	I-Application
system	O
on	O
macOS	O
that	O
was	O
introduced	O
by	O
Apple	O
to	O
Mac	B-Application
OS	I-Application
X	I-Application
Lion	I-Application
.	O
</s>
<s>
Core	B-Operating_System
Storage	I-Operating_System
is	O
a	O
layer	O
between	O
the	O
disk	B-Application
partition	I-Application
and	O
the	O
file	B-Application
system	I-Application
.	O
</s>
<s>
Core	B-Operating_System
Storage	I-Operating_System
is	O
the	O
basis	O
for	O
Apple	O
's	O
Fusion	B-Device
Drive	I-Device
technology	O
,	O
which	O
presents	O
several	O
partitions	B-Application
on	O
multiple	O
drives	O
as	O
a	O
single	O
logical	B-Application
volume	I-Application
.	O
</s>
<s>
It	O
does	O
this	O
by	O
using	O
tiered	B-General_Concept
storage	I-General_Concept
,	O
whereby	O
it	O
keeps	O
the	O
most	O
frequently	O
used	O
blocks	O
on	O
the	O
fastest	O
storage	O
device	O
in	O
the	O
pool	O
,	O
which	O
is	O
,	O
by	O
default	O
,	O
an	O
SSD	O
.	O
</s>
<s>
Apple	O
CoreStorage	B-Operating_System
defines	O
four	O
types	O
of	O
objects	O
,	O
instances	O
of	O
which	O
are	O
uniquely	O
represented	O
by	O
a	O
UUID	O
:	O
</s>
<s>
A	O
disk	O
offered	O
to	O
be	O
a	O
PV	O
must	O
be	O
a	O
partition	B-Application
and	O
the	O
encompassing	O
scheme	O
must	O
be	O
GPT	O
.	O
</s>
<s>
This	O
is	O
the	O
equivalent	O
of	O
volume	B-Application
groups	I-Application
in	O
Linux	B-Application
LVM	I-Application
.	O
</s>
<s>
The	O
Logical	B-Application
Volume	I-Application
Group	O
(	O
LVG	O
)	O
is	O
the	O
top	O
or	O
"	O
pool	O
"	O
level	O
;	O
zero	O
or	O
more	O
may	O
exist	O
during	O
any	O
OS	O
boot	O
time	O
session	O
.	O
</s>
<s>
An	O
LVG	O
exports	O
zero	O
or	O
more	O
Logical	B-Application
Volume	I-Application
Families	O
(	O
LVFs	O
)	O
.	O
</s>
<s>
An	O
LVF	O
contains	O
properties	O
which	O
govern	O
and	O
bind	O
together	O
all	O
of	O
its	O
descendant	O
Logical	B-Application
Volumes	I-Application
(	O
LVs	O
)	O
.	O
</s>
<s>
A	O
logical	B-Application
volume	I-Application
exports	O
a	O
dev	O
node	O
,	O
upon	O
which	O
a	O
file	B-Application
system	I-Application
(	O
such	O
as	O
Journaled	O
HFS+	O
)	O
resides	O
.	O
</s>
