<s>
Disaggregated	B-General_Concept
storage	I-General_Concept
is	O
a	O
type	O
of	O
data	B-General_Concept
storage	I-General_Concept
within	O
computer	O
data	B-Operating_System
centers	I-Operating_System
.	O
</s>
<s>
It	O
allows	O
compute	O
resources	O
within	O
a	O
computer	B-Application
server	I-Application
to	O
be	O
separated	O
from	O
storage	O
resources	O
without	O
modifying	O
any	O
physical	O
connections	O
.	O
</s>
<s>
A	O
form	O
of	O
composable	B-Architecture
disaggregated	I-Architecture
infrastructure	I-Architecture
,	O
disaggregated	B-General_Concept
storage	I-General_Concept
allows	O
resources	O
to	O
be	O
connected	O
via	O
a	O
network	B-Architecture
fabric	O
providing	O
flexibility	O
when	O
upgrading	O
,	O
replacing	O
,	O
or	O
adding	O
individual	O
resources	O
.	O
</s>
<s>
It	O
also	O
allows	O
servers	O
to	O
be	O
built	O
for	O
future	O
growth	O
,	O
offering	O
greater	O
storage	O
efficiency	O
,	O
scale	O
and	O
performance	O
than	O
traditional	O
data	B-General_Concept
storage	I-General_Concept
without	O
compromising	O
throughput	O
and	O
latency	O
.	O
</s>
<s>
In	O
the	O
past	O
,	O
data	B-Operating_System
center	I-Operating_System
storage	O
existed	O
in	O
two	O
forms	O
.	O
</s>
<s>
Direct-attached	B-General_Concept
storage	I-General_Concept
–	O
disks	O
or	O
drives	O
attached	O
to	O
a	O
single	O
server	O
.	O
</s>
<s>
Disk	B-General_Concept
capacity	I-General_Concept
and	O
performance	O
were	O
available	O
to	O
that	O
server	O
,	O
and	O
only	O
that	O
server	O
.	O
</s>
<s>
Capacity	O
expansion	O
was	O
limited	O
to	O
the	O
number	O
of	O
drive	B-Device
bays	I-Device
in	O
the	O
server	O
or	O
the	O
limits	O
of	O
expansion	O
chassis	O
.	O
</s>
<s>
Storage	O
area	O
networks	O
–	O
disks	O
or	O
drives	O
in	O
a	O
storage	B-General_Concept
array	I-General_Concept
which	O
could	O
be	O
provisioned	O
to	O
one	O
or	O
many	O
servers	O
on	O
the	O
network	B-Architecture
.	O
</s>
<s>
Direct-attached	B-General_Concept
storage	I-General_Concept
has	O
one	O
critical	O
advantage	O
—	O
it	O
offers	O
high-performance	O
for	O
any	O
workloads	O
running	O
on	O
that	O
server	O
.	O
</s>
<s>
Overall	O
performance	O
across	O
the	O
network	B-Architecture
is	O
low	O
,	O
as	O
storage	O
ca	O
n't	O
be	O
shared	O
over	O
the	O
network	B-Architecture
without	O
performance	O
impact	O
.	O
</s>
<s>
Capacity	O
utilization	O
is	O
low	O
because	O
disk	B-General_Concept
capacity	I-General_Concept
ca	O
n't	O
be	O
directly	O
used	O
by	O
other	O
servers	O
.	O
</s>
<s>
Storage	O
area	O
networks	O
are	O
used	O
to	O
allocate	O
storage	O
to	O
dozens	O
or	O
possibly	O
hundreds	O
of	O
servers	O
,	O
which	O
increases	O
capacity	O
utilization	O
,	O
but	O
storage	O
area	O
networks	O
use	O
specialized	O
network	B-Device
hardware	I-Device
and/or	O
protocols	O
that	O
can	O
come	O
with	O
disadvantages	O
.	O
</s>
<s>
Conventional	O
storage	O
networking	O
does	O
not	O
provide	O
sufficient	O
throughput	O
or	O
latency	O
minimization	O
needed	O
by	O
many	O
applications	O
,	O
and	O
fails	O
to	O
provide	O
enough	O
bandwidth	O
to	O
utilize	O
the	O
full	O
performance	O
of	O
new	O
flash	B-Device
technologies	I-Device
.	O
</s>
<s>
Disaggregated	B-General_Concept
storage	I-General_Concept
is	O
a	O
form	O
of	O
scale-out	O
storage	O
,	O
built	O
with	O
some	O
number	O
of	O
storage	O
devices	O
that	O
function	O
as	O
a	O
logical	O
pool	O
of	O
storage	O
that	O
can	O
be	O
allocated	O
to	O
any	O
server	O
on	O
the	O
network	B-Architecture
over	O
a	O
very	O
high	O
performance	O
network	B-Architecture
fabric	O
.	O
</s>
<s>
Disaggregated	B-General_Concept
storage	I-General_Concept
solves	O
the	O
limitations	O
of	O
storage	O
area	O
networks	O
or	O
direct-attached	B-General_Concept
storage	I-General_Concept
.	O
</s>
<s>
Disaggregated	B-General_Concept
storage	I-General_Concept
is	O
dynamically	O
reconfigurable	O
and	O
optimally	O
reconfigures	O
physical	O
resources	O
to	O
maximize	O
performance	O
and	O
limit	O
latency	O
.	O
</s>
<s>
Disaggregated	B-General_Concept
storage	I-General_Concept
provides	O
the	O
performance	O
of	O
local	O
storage	O
with	O
the	O
flexibility	O
of	O
storage	O
area	O
networks	O
.	O
</s>
<s>
The	O
shift	O
toward	O
NVMe	B-Application
:	O
The	O
shift	O
from	O
disk	O
to	O
SAS/SATA	O
flash	O
,	O
and	O
now	O
NVMe	B-Application
flash	O
,	O
puts	O
pressure	O
on	O
servers	O
and	O
networks	O
alike	O
.	O
</s>
<s>
A	O
single	O
NVMe	B-Application
drive	O
delivers	O
millions	O
of	O
IOPS	O
,	O
far	O
beyond	O
the	O
usual	O
capabilities	O
of	O
conventional	O
storage	O
networking	O
.	O
</s>
<s>
10Gb/25Gb/40Gb/100Gb	O
Ethernet	O
.	O
</s>
<s>
More	O
and	O
more	O
data	B-Operating_System
centers	I-Operating_System
are	O
replacing	O
slower	O
network	B-Architecture
connections	O
with	O
faster	O
Ethernet	O
,	O
removing	O
bandwidth	O
limitations	O
and	O
bottlenecks	O
.	O
</s>
<s>
Protocols	O
like	O
NVMe-oF	O
on	O
these	O
very	O
high	O
bandwidth	O
connections	O
take	O
full	O
advantage	O
of	O
network	B-Architecture
improvements	O
,	O
removing	O
bottlenecks	O
,	O
boosting	O
performance	O
and	O
reducing	O
latency	O
.	O
</s>
<s>
Different	O
levels	O
of	O
storage	O
disaggregation	O
functionality	O
exist	O
,	O
with	O
the	O
most	O
flexible	O
,	O
full	O
disaggregation	O
,	O
enabling	O
storage	B-General_Concept
capacity	I-General_Concept
and/or	O
performance	O
to	O
be	O
provisioned	O
from	O
any	O
storage	O
device	O
to	O
any	O
server	O
on	O
the	O
network	B-Architecture
,	O
then	O
expanded	O
,	O
shrunk	O
,	O
or	O
reprovisioned	O
as	O
new	O
requirements	O
emerge	O
.	O
</s>
