<s>
Distributed	B-General_Concept
block	I-General_Concept
storage	I-General_Concept
is	O
a	O
computer	B-General_Concept
data	I-General_Concept
storage	I-General_Concept
architecture	O
that	O
the	O
data	O
is	O
stored	O
in	O
volumes	O
(	O
known	O
as	O
blocks	O
:	O
)	O
across	O
multiple	O
physical	O
servers	O
,	O
as	O
opposed	O
to	O
other	O
storage	O
architectures	O
like	O
file	O
systems	O
which	O
manages	O
data	O
as	O
a	O
file	O
hierarchy	O
,	O
and	O
object	O
storage	O
which	O
manages	O
data	O
as	O
objects	O
.	O
</s>
<s>
A	O
common	O
distributed	B-General_Concept
block	I-General_Concept
storage	I-General_Concept
system	O
is	O
a	O
Storage	O
Area	O
Network	O
(	O
SAN	O
)	O
.	O
</s>
<s>
Scalability	O
:	O
support	O
to	O
scale	O
the	O
storage	B-General_Concept
system	I-General_Concept
horizontally	O
by	O
adding	O
or	O
removing	O
storage	O
units	O
to	O
the	O
system	O
.	O
</s>
<s>
Storage	O
blocks	O
are	O
generally	O
accessed	O
by	O
iSCSI	B-Protocol
,	O
Fibre	B-Architecture
Channel	I-Architecture
or	O
Fibre	B-Protocol
Channel	I-Protocol
over	I-Protocol
Ethernet	I-Protocol
(	O
FCoE	B-Protocol
)	O
protocols	O
.	O
</s>
