<s>
Lustre	B-Application
is	O
a	O
type	O
of	O
parallel	O
distributed	B-Protocol
file	I-Protocol
system	I-Protocol
,	O
generally	O
used	O
for	O
large-scale	O
cluster	B-Architecture
computing	I-Architecture
.	O
</s>
<s>
The	O
name	O
Lustre	B-Application
is	O
a	O
portmanteau	O
word	O
derived	O
from	O
Linux	B-Application
and	O
cluster	B-Architecture
.	O
</s>
<s>
Lustre	B-Application
file	B-Application
system	I-Application
software	O
is	O
available	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
version	O
2	O
only	O
)	O
and	O
provides	O
high	O
performance	O
file	B-Application
systems	I-Application
for	O
computer	B-Architecture
clusters	I-Architecture
ranging	O
in	O
size	O
from	O
small	O
workgroup	O
clusters	O
to	O
large-scale	O
,	O
multi-site	O
systems	O
.	O
</s>
<s>
Since	O
June	O
2005	O
,	O
Lustre	B-Application
has	O
consistently	O
been	O
used	O
by	O
at	O
least	O
half	O
of	O
the	O
top	O
ten	O
,	O
and	O
more	O
than	O
60	O
of	O
the	O
top	O
100	O
fastest	B-Operating_System
supercomputers	I-Operating_System
in	O
the	O
world	O
,	O
</s>
<s>
1	O
ranked	O
TOP500	B-Operating_System
supercomputer	B-Architecture
in	O
November	O
2022	O
,	O
Frontier	B-Device
,	O
as	O
well	O
as	O
previous	O
top	O
supercomputers	B-Architecture
such	O
as	O
Fugaku	B-Device
,	O
Titan	B-Device
and	O
Sequoia	B-Device
.	O
</s>
<s>
Lustre	B-Application
file	B-Application
systems	I-Application
are	O
scalable	O
and	O
can	O
be	O
part	O
of	O
multiple	O
computer	B-Architecture
clusters	I-Architecture
with	O
tens	O
of	O
thousands	O
of	O
client	B-Protocol
nodes	O
,	O
tens	O
of	O
petabytes	O
(	O
PB	O
)	O
of	O
storage	O
on	O
hundreds	O
of	O
servers	O
,	O
and	O
more	O
than	O
a	O
terabyte	O
per	O
second	O
(	O
TB/s	O
)	O
of	O
aggregate	O
I/O	O
throughput	O
.	O
</s>
<s>
This	O
makes	O
Lustre	B-Application
file	B-Application
systems	I-Application
a	O
popular	O
choice	O
for	O
businesses	O
with	O
large	O
data	O
centers	O
,	O
including	O
those	O
in	O
industries	O
such	O
as	O
meteorology	O
,	O
simulation	O
,	O
oil	O
and	O
gas	O
,	O
life	O
science	O
,	O
rich	O
media	O
,	O
and	O
finance	O
.	O
</s>
<s>
The	O
I/O	O
performance	O
of	O
Lustre	B-Application
has	O
widespread	O
impact	O
on	O
these	O
applications	O
and	O
has	O
attracted	O
broad	O
attention	O
.	O
</s>
<s>
The	O
Lustre	B-Application
file	B-Application
system	I-Application
architecture	O
was	O
started	O
as	O
a	O
research	O
project	O
in	O
1999	O
by	O
Peter	O
J	O
.	O
Braam	O
,	O
who	O
was	O
a	O
staff	O
of	O
Carnegie	O
Mellon	O
University	O
(	O
CMU	O
)	O
at	O
the	O
time	O
.	O
</s>
<s>
Braam	O
went	O
on	O
to	O
found	O
his	O
own	O
company	O
Cluster	B-Application
File	I-Application
Systems	I-Application
in	O
2001	O
,	O
starting	O
from	O
work	O
on	O
the	O
InterMezzo	B-Application
file	I-Application
system	I-Application
in	O
the	O
Coda	B-Application
project	I-Application
at	O
CMU	O
.	O
</s>
<s>
Lustre	B-Application
was	O
developed	O
under	O
the	O
Accelerated	B-General_Concept
Strategic	I-General_Concept
Computing	I-General_Concept
Initiative	I-General_Concept
Path	O
Forward	O
project	O
funded	O
by	O
the	O
United	O
States	O
Department	O
of	O
Energy	O
,	O
which	O
included	O
Hewlett-Packard	O
and	O
Intel	O
.	O
</s>
<s>
In	O
September	O
2007	O
,	O
Sun	O
Microsystems	O
acquired	O
the	O
assets	O
of	O
Cluster	B-Application
File	I-Application
Systems	I-Application
Inc	O
.	O
including	O
its	O
”	O
intellectual	O
property	O
“	O
.	O
</s>
<s>
Sun	O
included	O
Lustre	B-Application
with	O
its	O
high-performance	B-Architecture
computing	I-Architecture
hardware	O
offerings	O
,	O
with	O
the	O
intent	O
to	O
bring	O
Lustre	B-Application
technologies	O
to	O
Sun	O
's	O
ZFS	B-Application
file	B-Application
system	I-Application
and	O
the	O
Solaris	B-Application
operating	I-Application
system	I-Application
.	O
</s>
<s>
In	O
2010	O
Oracle	B-Application
Corporation	I-Application
,	O
by	O
way	O
of	O
its	O
acquisition	O
of	O
Sun	O
,	O
began	O
to	O
manage	O
and	O
release	O
Lustre	B-Application
.	O
</s>
<s>
In	O
December	O
2010	O
,	O
Oracle	B-Application
announced	O
that	O
they	O
would	O
cease	O
Lustre	B-Application
2.x	O
development	O
and	O
place	O
Lustre	B-Application
1.8	O
into	O
maintenance-only	O
support	O
,	O
creating	O
uncertainty	O
around	O
the	O
future	O
development	O
of	O
the	O
file	B-Application
system	I-Application
.	O
</s>
<s>
Open	O
Scalable	O
File	B-Application
Systems	I-Application
,	O
Inc	O
.	O
(	O
OpenSFS	B-Application
)	O
,	O
EUROPEAN	O
Open	O
File	B-Application
Systems	I-Application
(	O
EOFS	B-Application
)	O
and	O
others	O
.	O
</s>
<s>
By	O
the	O
end	O
of	O
2010	O
,	O
most	O
Lustre	B-Application
developers	O
had	O
left	O
Oracle	B-Application
.	O
</s>
<s>
while	O
Barton	O
,	O
Dilger	O
,	O
and	O
others	O
formed	O
software	O
startup	O
Whamcloud	O
,	O
where	O
they	O
continued	O
to	O
work	O
on	O
Lustre	B-Application
.	O
</s>
<s>
In	O
August	O
2011	O
,	O
OpenSFS	B-Application
awarded	O
a	O
contract	O
for	O
Lustre	B-Application
feature	O
development	O
to	O
Whamcloud	O
.	O
</s>
<s>
This	O
contract	O
covered	O
the	O
completion	O
of	O
features	O
,	O
including	O
improved	O
Single	O
Server	O
Metadata	O
Performance	O
scaling	O
,	O
which	O
allows	O
Lustre	B-Application
to	O
better	O
take	O
advantage	O
of	O
many-core	O
metadata	O
server	O
;	O
online	O
Lustre	B-Application
distributed	O
filesystem	B-Application
checking	O
(	O
LFSCK	O
)	O
,	O
which	O
allows	O
verification	O
of	O
the	O
distributed	O
filesystem	B-Application
state	O
between	O
data	O
and	O
metadata	O
servers	O
while	O
the	O
filesystem	B-Application
is	O
mounted	O
and	O
in	O
use	O
;	O
and	O
Distributed	O
Namespace	O
Environment	O
(	O
DNE	O
)	O
,	O
formerly	O
Clustered	O
Metadata	O
(	O
CMD	O
)	O
,	O
which	O
allows	O
the	O
Lustre	B-Application
metadata	O
to	O
be	O
distributed	O
across	O
multiple	O
servers	O
.	O
</s>
<s>
Development	O
also	O
continued	O
on	O
ZFS-based	O
back-end	O
object	B-Application
storage	I-Application
at	O
Lawrence	O
Livermore	O
National	O
Laboratory	O
.	O
</s>
<s>
These	O
features	O
were	O
in	O
the	O
Lustre	B-Application
2.2	O
through	O
2.4	O
community	O
release	O
roadmap	O
.	O
</s>
<s>
In	O
November	O
2011	O
,	O
a	O
separate	O
contract	O
was	O
awarded	O
to	O
Whamcloud	O
for	O
the	O
maintenance	O
of	O
the	O
Lustre	B-Application
2.x	O
source	O
code	O
to	O
ensure	O
that	O
the	O
Lustre	B-Application
code	O
would	O
receive	O
sufficient	O
testing	O
and	O
bug	O
fixing	O
while	O
new	O
features	O
were	O
being	O
developed	O
.	O
</s>
<s>
In	O
July	O
2012	O
Whamcloud	O
was	O
acquired	O
by	O
Intel	O
,	O
after	O
Whamcloud	O
won	O
the	O
FastForward	O
DOE	O
contract	O
to	O
extend	O
Lustre	B-Application
for	O
exascale	B-General_Concept
computing	I-General_Concept
systems	O
in	O
the	O
2012	O
timeframe	O
.	O
</s>
<s>
OpenSFS	B-Application
then	O
transitioned	O
contracts	O
for	O
Lustre	B-Application
development	O
to	O
Intel	O
.	O
</s>
<s>
In	O
February	O
2013	O
,	O
Xyratex	O
Ltd.	O
,	O
announced	O
it	O
acquired	O
the	O
original	O
Lustre	B-Application
trademark	O
,	O
logo	O
,	O
website	O
and	O
associated	O
intellectual	O
property	O
from	O
Oracle	B-Application
.	O
</s>
<s>
In	O
June	O
2013	O
,	O
Intel	O
began	O
expanding	O
Lustre	B-Application
usage	O
beyond	O
traditional	O
HPC	O
,	O
such	O
as	O
within	O
Hadoop	B-Application
.	O
</s>
<s>
For	O
2013	O
as	O
a	O
whole	O
,	O
OpenSFS	B-Application
announced	O
request	O
for	O
proposals	O
(	O
RFP	O
)	O
to	O
cover	O
Lustre	B-Application
feature	O
development	O
,	O
parallel	O
file	B-Application
system	I-Application
tools	O
,	O
addressing	O
Lustre	B-Application
technical	O
debt	O
,	O
and	O
parallel	O
file	B-Application
system	I-Application
incubators	O
.	O
</s>
<s>
OpenSFS	B-Application
also	O
established	O
the	O
Lustre	B-Application
Community	O
Portal	O
,	O
a	O
technical	O
site	O
that	O
provides	O
a	O
collection	O
of	O
information	O
and	O
documentation	O
in	O
one	O
area	O
for	O
reference	O
and	O
guidance	O
to	O
support	O
the	O
Lustre	B-Application
open	O
source	O
community	O
.	O
</s>
<s>
In	O
June	O
2018	O
,	O
the	O
Lustre	B-Application
team	O
and	O
assets	O
were	O
acquired	O
from	O
Intel	O
by	O
DDN	O
.	O
</s>
<s>
In	O
November	O
2019	O
,	O
OpenSFS	B-Application
and	O
EOFS	B-Application
announced	O
at	O
the	O
SC19	O
Lustre	B-Application
BOF	O
that	O
the	O
Lustre	B-Application
trademark	O
had	O
been	O
transferred	O
to	O
them	O
jointly	O
from	O
Seagate	O
.	O
</s>
<s>
Lustre	B-Application
file	B-Application
system	I-Application
was	O
first	O
installed	O
for	O
production	O
use	O
in	O
March	O
2003	O
on	O
the	O
MCR	O
Linux	B-Architecture
Cluster	I-Architecture
at	O
the	O
Lawrence	O
Livermore	O
National	O
Laboratory	O
,	O
one	O
of	O
the	O
largest	O
supercomputers	B-Architecture
at	O
the	O
time	O
.	O
</s>
<s>
Lustre	B-Application
1.0.0	O
was	O
released	O
in	O
December	O
2003	O
,	O
and	O
provided	O
basic	O
Lustre	B-Application
filesystem	B-Application
functionality	O
,	O
including	O
server	O
failover	O
and	O
recovery	O
.	O
</s>
<s>
Lustre	B-Application
1.2.0	O
,	O
released	O
in	O
March	O
2004	O
,	O
worked	O
on	O
Linux	B-Operating_System
kernel	I-Operating_System
2.6	I-Operating_System
,	O
and	O
had	O
a	O
"	O
size	O
glimpse	O
"	O
feature	O
to	O
avoid	O
lock	O
revocation	O
on	O
files	O
undergoing	O
write	O
,	O
and	O
client	B-Protocol
side	O
data	O
write-back	O
cache	O
accounting	O
(	O
grant	O
)	O
.	O
</s>
<s>
Lustre	B-Application
1.4.0	O
,	O
released	O
in	O
November	O
2004	O
,	O
provided	O
protocol	O
compatibility	O
between	O
versions	O
,	O
could	O
use	O
InfiniBand	B-Architecture
networks	O
,	O
and	O
could	O
exploit	O
extents/mballoc	O
in	O
the	O
ldiskfs	B-Application
on-disk	O
filesystem	B-Application
.	O
</s>
<s>
Lustre	B-Application
1.6.0	O
,	O
released	O
in	O
April	O
2007	O
,	O
allowed	O
mount	O
configuration	O
(	O
“	O
mountconf	O
”	O
)	O
allowing	O
servers	O
to	O
be	O
configured	O
with	O
"	O
mkfs	O
"	O
and	O
"	O
mount	O
"	O
,	O
allowed	O
dynamic	O
addition	O
of	O
object	B-Application
storage	I-Application
targets	O
(	O
OSTs	O
)	O
,	O
enabled	O
Lustre	B-Application
distributed	B-Operating_System
lock	I-Operating_System
manager	I-Operating_System
(	O
LDLM	O
)	O
scalability	O
on	O
symmetric	B-Operating_System
multiprocessing	I-Operating_System
(	O
SMP	O
)	O
servers	O
,	O
and	O
provided	O
free	O
space	O
management	O
for	O
object	O
allocations	O
.	O
</s>
<s>
Lustre	B-Application
1.8.0	O
,	O
released	O
in	O
May	O
2009	O
,	O
provided	O
OSS	O
Read	O
Cache	O
,	O
improved	O
recovery	O
in	O
the	O
face	O
of	O
multiple	O
failures	O
,	O
added	O
basic	O
heterogeneous	O
storage	O
management	O
via	O
OST	O
Pools	O
,	O
adaptive	O
network	O
timeouts	O
,	O
and	O
version-based	O
recovery	O
.	O
</s>
<s>
It	O
was	O
a	O
transition	O
release	O
,	O
being	O
interoperable	O
with	O
both	O
Lustre	B-Application
1.6	O
and	O
Lustre	B-Application
2.0	O
.	O
</s>
<s>
Lustre	B-Application
2.0	O
,	O
released	O
in	O
August	O
2010	O
,	O
was	O
based	O
on	O
significant	O
internally	O
restructured	O
code	O
to	O
prepare	O
for	O
major	O
architectural	O
advancements	O
.	O
</s>
<s>
Lustre	B-Application
2.x	O
clients	O
cannot	O
interoperate	O
with	O
1.8	O
or	O
earlier	O
servers	O
.	O
</s>
<s>
However	O
,	O
Lustre	B-Application
1.8.6	O
and	O
later	O
clients	O
can	O
interoperate	O
with	O
Lustre	B-Application
2.0	O
and	O
later	O
servers	O
.	O
</s>
<s>
The	O
Metadata	O
Target	O
(	O
MDT	O
)	O
and	O
OST	O
on-disk	O
format	O
from	O
1.8	O
can	O
be	O
upgraded	O
to	O
2.0	O
and	O
later	O
without	O
the	O
need	O
to	O
reformat	O
the	O
filesystem	B-Application
.	O
</s>
<s>
Lustre	B-Application
2.1	O
,	O
released	O
in	O
September	O
2011	O
,	O
was	O
a	O
community-wide	O
initiative	O
in	O
response	O
to	O
Oracle	B-Application
suspending	O
development	O
on	O
Lustre	B-Application
2.x	O
releases	O
.	O
</s>
<s>
It	O
added	O
the	O
ability	O
to	O
run	O
servers	O
on	O
Red	O
Hat	O
Linux	B-Application
6	O
and	O
increased	O
the	O
maximum	O
ext4-based	O
OST	O
size	O
from	O
24TB	O
to	O
128TB	O
,	O
as	O
well	O
as	O
a	O
number	O
of	O
performance	O
and	O
stability	O
improvements	O
.	O
</s>
<s>
Lustre	B-Application
2.1	O
servers	O
remained	O
inter-operable	O
with	O
1.8.6	O
and	O
later	O
clients	O
.	O
</s>
<s>
Lustre	B-Application
2.2	O
,	O
released	O
in	O
March	O
2012	O
,	O
focused	O
on	O
providing	O
metadata	O
performance	O
improvements	O
and	O
new	O
features	O
.	O
</s>
<s>
It	O
added	O
parallel	O
directory	O
operations	O
allowing	O
multiple	O
clients	O
to	O
traverse	O
and	O
modify	O
a	O
single	O
large	O
directory	O
concurrently	O
,	O
faster	O
recovery	O
from	O
server	O
failures	O
,	O
increased	O
stripe	O
counts	O
for	O
a	O
single	O
file	O
(	O
across	O
up	O
to	O
2000	O
OSTs	O
)	O
,	O
and	O
improved	O
single-client	O
directory	O
traversal	O
performance	O
.	O
</s>
<s>
Lustre	B-Application
2.3	O
,	O
released	O
in	O
October	O
2012	O
,	O
continued	O
to	O
improve	O
the	O
metadata	O
server	O
code	O
to	O
remove	O
internal	O
locking	O
bottlenecks	O
on	O
nodes	O
with	O
many	O
CPU	O
cores	O
(	O
over	O
16	O
)	O
.	O
</s>
<s>
The	O
object	O
store	O
added	O
a	O
preliminary	O
ability	O
to	O
use	O
ZFS	B-Application
as	O
the	O
backing	O
file	B-Application
system	I-Application
.	O
</s>
<s>
The	O
Lustre	B-Application
File	B-Application
System	I-Application
ChecK	O
(	O
LFSCK	O
)	O
feature	O
can	O
verify	O
and	O
repair	O
the	O
MDS	O
Object	O
Index	O
(	O
OI	O
)	O
while	O
the	O
file	B-Application
system	I-Application
is	O
in	O
use	O
,	O
after	O
a	O
file-level	O
backup/restore	O
or	O
in	O
case	O
of	O
MDS	O
corruption	O
.	O
</s>
<s>
The	O
server-side	O
IO	O
statistics	O
were	O
enhanced	O
to	O
allow	O
integration	O
with	O
batch	O
job	O
schedulers	O
such	O
as	O
SLURM	B-Operating_System
to	O
track	O
per-job	O
statistics	O
.	O
</s>
<s>
Client-side	O
software	O
was	O
updated	O
to	O
work	O
with	O
Linux	B-Operating_System
kernels	I-Operating_System
up	O
to	O
version	O
3.0	O
.	O
</s>
<s>
Lustre	B-Application
2.4	O
,	O
released	O
in	O
May	O
2013	O
,	O
added	O
a	O
considerable	O
number	O
of	O
major	O
features	O
,	O
many	O
funded	O
directly	O
through	O
OpenSFS	B-Application
.	O
</s>
<s>
ZFS	B-Application
can	O
now	O
be	O
used	O
as	O
the	O
backing	O
filesystem	B-Application
for	O
both	O
MDT	O
and	O
OST	O
storage	O
.	O
</s>
<s>
(	O
NRS	O
)	O
adds	O
policies	O
to	O
optimize	O
client	B-Protocol
request	O
processing	O
for	O
disk	O
ordering	O
or	O
fairness	O
.	O
</s>
<s>
Client-side	O
software	O
was	O
updated	O
to	O
work	O
with	O
Linux	B-Operating_System
kernels	I-Operating_System
up	O
to	O
version	O
3.6	O
,	O
and	O
is	O
still	O
interoperable	O
with	O
1.8	O
clients	O
.	O
</s>
<s>
Lustre	B-Application
2.5	O
,	O
released	O
in	O
October	O
2013	O
,	O
added	O
the	O
highly	O
anticipated	O
feature	O
,	O
Hierarchical	B-Application
Storage	I-Application
Management	I-Application
(	O
HSM	B-Application
)	O
.	O
</s>
<s>
A	O
core	O
requirement	O
in	O
enterprise	O
environments	O
,	O
HSM	B-Application
allows	O
customers	O
to	O
easily	O
implement	O
tiered	O
storage	O
solutions	O
in	O
their	O
operational	O
environment	O
.	O
</s>
<s>
This	O
release	O
is	O
the	O
current	O
OpenSFS-designated	O
Maintenance	O
Release	O
branch	O
of	O
Lustre	B-Application
.	O
</s>
<s>
Lustre	B-Application
2.6	O
,	O
released	O
in	O
July	O
2014	O
,	O
was	O
a	O
more	O
modest	O
release	O
feature	O
wise	O
,	O
adding	O
LFSCK	O
functionality	O
to	O
do	O
local	O
consistency	O
checks	O
on	O
the	O
OST	O
as	O
well	O
as	O
consistency	O
checks	O
between	O
MDT	O
and	O
OST	O
objects	O
.	O
</s>
<s>
(	O
TBF	B-Algorithm
)	O
policy	O
was	O
added	O
.	O
</s>
<s>
Single-client	O
IO	O
performance	O
was	O
improved	O
over	O
the	O
previous	O
releases	O
.	O
</s>
<s>
Lustre	B-Application
2.7	O
,	O
released	O
in	O
March	O
2015	O
,	O
added	O
LFSCK	O
functionality	O
to	O
verify	O
DNE	O
consistency	O
of	O
remote	O
and	O
striped	O
directories	O
between	O
multiple	O
MDTs	O
.	O
</s>
<s>
Lustre	B-Application
2.8	O
,	O
released	O
in	O
March	O
2016	O
,	O
finished	O
the	O
DNE	O
striped	O
directory	O
feature	O
,	O
including	O
support	O
for	O
migrating	O
directories	O
between	O
MDTs	O
,	O
and	O
cross-MDT	O
hard	B-Application
link	I-Application
and	O
rename	O
.	O
</s>
<s>
As	O
well	O
,	O
it	O
included	O
improved	O
support	O
for	O
Security-Enhanced	B-Application
Linux	I-Application
(	O
SELinux	B-Application
)	O
on	O
the	O
client	B-Protocol
,	O
Kerberos	B-Protocol
authentication	O
and	O
RPC	O
encryption	O
over	O
the	O
network	O
,	O
and	O
performance	O
improvements	O
for	O
LFSCK	O
.	O
</s>
<s>
The	O
Shared	O
Secret	O
Key	O
security	O
flavour	O
uses	O
the	O
same	O
GSSAPI	O
mechanism	O
as	O
Kerberos	B-Protocol
to	O
provide	O
client	B-Protocol
and	O
server	O
node	O
authentication	O
,	O
and	O
RPC	O
message	O
integrity	O
and	O
security	O
(	O
encryption	O
)	O
.	O
</s>
<s>
The	O
Nodemap	O
feature	O
allows	O
categorizing	O
client	B-Protocol
nodes	O
into	O
groups	O
and	O
then	O
mapping	O
the	O
UID/GID	O
for	O
those	O
clients	O
,	O
allowing	O
remotely	O
administered	O
clients	O
to	O
transparently	O
use	O
a	O
shared	O
filesystem	B-Application
without	O
having	O
a	O
single	O
set	O
of	O
UID/GIDs	O
for	O
all	O
client	B-Protocol
nodes	O
.	O
</s>
<s>
The	O
subdirectory	O
mount	O
feature	O
allows	O
clients	O
to	O
mount	O
a	O
subset	O
of	O
the	O
filesystem	B-Application
namespace	O
from	O
the	O
MDS	O
.	O
</s>
<s>
There	O
was	O
improved	O
support	O
for	O
specifying	O
filesystem-wide	O
default	O
OST	O
pools	O
,	O
and	O
improved	O
inheritance	O
of	O
OST	O
pools	O
in	O
conjunction	O
with	O
other	O
file	O
layout	O
parameters	O
.	O
</s>
<s>
The	O
(	O
LMR	O
)	O
feature	O
allows	O
bonding	B-Architecture
multiple	O
network	O
interfaces	O
(	O
InfiniBand	B-Architecture
,	O
Omni-Path	B-Operating_System
,	O
and/or	O
Ethernet	O
)	O
on	O
a	O
client	B-Protocol
and	O
server	O
to	O
increase	O
aggregate	O
I/O	O
bandwidth	O
.	O
</s>
<s>
The	O
NRS	O
Token	B-Algorithm
Bucket	I-Algorithm
Filter	I-Algorithm
(	O
TBF	B-Algorithm
)	O
server-side	O
scheduler	O
has	O
implemented	O
new	O
rule	O
types	O
,	O
including	O
RPC-type	O
scheduling	O
and	O
the	O
ability	O
to	O
specify	O
multiple	O
parameters	O
such	O
as	O
JobID	O
and	O
NID	O
for	O
rule	O
matching	O
.	O
</s>
<s>
Tools	O
for	O
managing	O
ZFS	B-Application
snapshots	O
of	O
Lustre	B-Application
filesystems	B-Application
have	O
been	O
added	O
,	O
to	O
simplify	O
the	O
creation	O
,	O
mounting	O
,	O
and	O
management	O
of	O
MDT	O
and	O
OST	O
ZFS	B-Application
snapshots	O
as	O
separate	O
Lustre	B-Application
mountpoints	O
.	O
</s>
<s>
The	O
(	O
DoM	O
)	O
feature	O
allows	O
small	O
(	O
few	O
MiB	O
)	O
files	O
to	O
be	O
stored	O
on	O
the	O
MDT	O
to	O
leverage	O
typical	O
flash-based	O
RAID-10	O
storage	O
for	O
lower	O
latency	O
and	O
reduced	O
IO	O
contention	O
,	O
instead	O
of	O
the	O
typical	O
HDD	O
RAID-6	O
storage	O
used	O
on	O
OSTs	O
.	O
</s>
<s>
The	O
LDLM	O
Lock	O
Ahead	O
feature	O
allows	O
appropriately	O
modified	O
applications	O
and	O
libraries	O
to	O
pre-fetch	O
DLM	O
extent	B-Application
locks	O
from	O
the	O
OSTs	O
for	O
files	O
,	O
if	O
the	O
application	O
knows	O
(	O
or	O
predicts	O
)	O
that	O
this	O
file	B-Application
extent	I-Application
will	O
be	O
modified	O
in	O
the	O
near	O
future	O
,	O
which	O
can	O
reduce	O
lock	O
contention	O
for	O
multiple	O
clients	O
writing	O
to	O
the	O
same	O
file	O
.	O
</s>
<s>
Lustre	B-Application
2.12	O
was	O
released	O
on	O
December	O
21	O
,	O
2018	O
and	O
focused	O
on	O
improving	O
Lustre	B-Application
usability	O
and	O
stability	O
,	O
with	O
improvements	O
the	O
performance	O
and	O
functionality	O
of	O
the	O
FLR	O
and	O
DoM	O
features	O
added	O
in	O
Lustre	B-Application
2.11	O
,	O
as	O
well	O
as	O
smaller	O
changes	O
to	O
NRS	O
TBF	B-Algorithm
,	O
HSM	B-Application
,	O
and	O
JobStats	O
.	O
</s>
<s>
It	O
added	O
to	O
allow	O
the	O
LNet	O
Multi-Rail	O
feature	O
from	O
Lustre	B-Application
2.10	O
to	O
better	O
handle	O
network	O
faults	O
when	O
a	O
node	O
has	O
multiple	O
network	O
interfaces	O
.	O
</s>
<s>
The	O
Lazy	O
Size	O
on	O
MDT	O
(	O
LSOM	O
)	O
feature	O
allows	O
storing	O
an	O
estimate	O
of	O
the	O
file	O
size	O
on	O
the	O
MDT	O
for	O
use	O
by	O
policy	O
engines	O
,	O
filesystem	B-Application
scanners	O
,	O
and	O
other	O
management	O
tools	O
that	O
can	O
more	O
efficiently	O
make	O
decisions	O
about	O
files	O
without	O
a	O
fully	O
accurate	O
file	O
sizes	O
or	O
blocks	O
count	O
without	O
having	O
to	O
query	O
the	O
OSTs	O
for	O
this	O
information	O
.	O
</s>
<s>
The	O
Lustre	B-Application
RPC	O
data	O
checksum	O
added	O
SCSI	B-Error_Name
T10-PI	I-Error_Name
integrated	O
data	O
checksums	O
from	O
the	O
client	B-Protocol
to	O
the	O
kernel	B-Operating_System
block	O
layer	O
,	O
SCSI	O
host	B-Architecture
adapter	I-Architecture
,	O
and	O
T10-enabled	O
hard	B-Device
drives	I-Device
.	O
</s>
<s>
Lustre	B-Application
2.13	O
was	O
released	O
on	O
December	O
5	O
,	O
2019	O
and	O
added	O
a	O
new	O
performance-related	O
features	O
Persistent	O
Client	B-Protocol
Cache	O
(	O
PCC	O
)	O
,	O
which	O
allows	O
direct	O
use	O
of	O
NVMe	B-Application
and	O
NVRAM	B-General_Concept
storage	O
on	O
the	O
client	B-Protocol
nodes	O
while	O
keeping	O
the	O
files	O
part	O
of	O
the	O
global	O
filesystem	B-Application
namespace	O
,	O
and	O
OST	O
Overstriping	O
which	O
allows	O
files	O
to	O
store	O
multiple	O
stripes	O
on	O
a	O
single	O
OST	O
to	O
better	O
utilize	O
fast	O
OSS	O
hardware	O
.	O
</s>
<s>
As	O
well	O
,	O
the	O
LNet	O
Multi-Rail	O
Network	O
Health	O
functionality	O
was	O
improved	O
to	O
work	O
with	O
LNet	O
RDMA	B-General_Concept
router	O
nodes	O
.	O
</s>
<s>
The	O
PFL	O
functionality	O
was	O
enhanced	O
with	O
Self-Extending	O
Layouts	O
(	O
SEL	O
)	O
to	O
allow	O
file	O
components	O
to	O
be	O
dynamically	O
sized	O
,	O
to	O
better	O
deal	O
with	O
flash	O
OSTs	O
that	O
may	O
be	O
much	O
smaller	O
than	O
disk	O
OSTs	O
within	O
the	O
same	O
filesystem	B-Application
.	O
</s>
<s>
The	O
release	O
also	O
included	O
a	O
number	O
of	O
smaller	O
improvements	O
,	O
such	O
as	O
balancing	O
DNE	O
remote	O
directory	O
creation	O
across	O
MDTs	O
,	O
using	O
Lazy-size-on-MDT	O
to	O
reduce	O
the	O
overhead	O
of	O
"	O
lfs	O
find	O
"	O
,	O
directories	O
with	O
10M	O
files	O
per	O
shard	B-General_Concept
for	O
ldiskfs	B-Application
,	O
and	O
bulk	O
RPC	O
sizes	O
up	O
to	O
64MB	O
.	O
</s>
<s>
Lustre	B-Application
2.14	O
was	O
released	O
on	O
February	O
19	O
,	O
2021	O
and	O
includes	O
three	O
main	O
features	O
.	O
</s>
<s>
Client	B-Protocol
Data	O
Encryption	O
implements	O
fscrypt	O
to	O
allow	O
file	O
data	O
to	O
be	O
encrypted	O
on	O
the	O
client	B-Protocol
before	O
network	O
transfer	O
and	O
persistent	O
storage	O
on	O
the	O
OST	O
and	O
MDT	O
.	O
</s>
<s>
Lustre	B-Application
2.15	O
was	O
released	O
on	O
June	O
16	O
,	O
2022	O
and	O
includes	O
three	O
main	O
features	O
.	O
</s>
<s>
expands	O
on	O
the	O
fscrypt	O
data	O
encryption	O
in	O
the	O
2.14	O
release	O
to	O
also	O
allow	O
file	O
and	O
directory	O
names	O
to	O
be	O
encrypted	O
on	O
the	O
client	B-Protocol
before	O
network	O
transfer	O
and	O
persistent	O
storage	O
on	O
the	O
MDT	O
.	O
</s>
<s>
DNE	O
MDT	O
space	O
balancing	O
automatically	O
balances	O
new	O
directory	O
creation	O
across	O
MDTs	O
in	O
the	O
filesystem	B-Application
in	O
round-robin	B-Algorithm
and/or	O
based	O
on	O
available	O
inodes	B-Application
and	O
space	O
,	O
which	O
in	O
turn	O
helps	O
distribute	O
client	B-Protocol
metadata	O
workload	O
over	O
MDTs	O
more	O
evenly	O
.	O
</s>
<s>
the	O
Lustre	B-Application
client	B-Protocol
can	O
do	O
zero-copy	O
RDMA	B-General_Concept
read	O
and	O
write	O
from	O
the	O
storage	O
server	O
directly	O
into	O
the	O
GPU	O
memory	O
to	O
avoid	O
an	O
extra	O
data	O
copy	O
from	O
CPU	O
memory	O
and	O
extra	O
processing	O
overhead	O
.	O
</s>
<s>
A	O
Lustre	B-Application
file	B-Application
system	I-Application
has	O
three	O
major	O
functional	O
units	O
:	O
</s>
<s>
One	O
or	O
more	O
metadata	O
servers	O
(	O
MDS	O
)	O
nodes	O
that	O
have	O
one	O
or	O
more	O
metadata	O
target	O
(	O
MDT	O
)	O
devices	O
per	O
Lustre	B-Application
filesystem	B-Application
that	O
stores	O
namespace	O
metadata	O
,	O
such	O
as	O
filenames	O
,	O
directories	O
,	O
access	O
permissions	O
,	O
and	O
file	O
layout	O
.	O
</s>
<s>
The	O
MDT	O
data	O
is	O
stored	O
in	O
a	O
local	O
disk	O
filesystem	B-Application
.	O
</s>
<s>
However	O
,	O
unlike	O
block-based	O
distributed	O
filesystems	B-Application
,	O
such	O
as	O
GPFS	B-Application
and	O
PanFS	O
,	O
where	O
the	O
metadata	O
server	O
controls	O
all	O
of	O
the	O
block	O
allocation	O
,	O
the	O
Lustre	B-Application
metadata	O
server	O
is	O
only	O
involved	O
in	O
pathname	O
and	O
permission	O
checks	O
,	O
and	O
is	O
not	O
involved	O
in	O
any	O
file	O
I/O	O
operations	O
,	O
avoiding	O
I/O	O
scalability	O
bottlenecks	O
on	O
the	O
metadata	O
server	O
.	O
</s>
<s>
The	O
ability	O
to	O
have	O
multiple	O
MDTs	O
in	O
a	O
single	O
filesystem	B-Application
is	O
a	O
new	O
feature	O
in	O
Lustre	B-Application
2.4	O
,	O
and	O
allows	O
directory	O
subtrees	O
to	O
reside	O
on	O
the	O
secondary	O
MDTs	O
,	O
while	O
2.7	O
and	O
later	O
allow	O
large	O
single	O
directories	O
to	O
be	O
distributed	O
across	O
multiple	O
MDTs	O
as	O
well	O
.	O
</s>
<s>
One	O
or	O
more	O
object	B-Application
storage	I-Application
server	O
(	O
OSS	O
)	O
nodes	O
that	O
store	O
file	O
data	O
on	O
one	O
or	O
more	O
object	B-Application
storage	I-Application
target	O
(	O
OST	O
)	O
devices	O
.	O
</s>
<s>
Depending	O
on	O
the	O
server	O
's	O
hardware	O
,	O
an	O
OSS	O
typically	O
serves	O
between	O
two	O
and	O
eight	O
OSTs	O
,	O
with	O
each	O
OST	O
managing	O
a	O
single	O
local	O
disk	O
filesystem	B-Application
.	O
</s>
<s>
The	O
capacity	O
of	O
a	O
Lustre	B-Application
file	B-Application
system	I-Application
is	O
the	O
sum	O
of	O
the	O
capacities	O
provided	O
by	O
the	O
OSTs	O
.	O
</s>
<s>
Client(s )	O
that	O
access	O
and	O
use	O
the	O
data	O
.	O
</s>
<s>
Lustre	B-Application
presents	O
all	O
clients	O
with	O
a	O
unified	O
namespace	O
for	O
all	O
of	O
the	O
files	O
and	O
data	O
in	O
the	O
filesystem	B-Application
,	O
using	O
standard	O
POSIX	O
semantics	O
,	O
and	O
allows	O
concurrent	O
and	O
coherent	O
read	O
and	O
write	O
access	O
to	O
the	O
files	O
in	O
the	O
filesystem	B-Application
.	O
</s>
<s>
The	O
MDT	O
,	O
OST	O
,	O
and	O
client	B-Protocol
may	O
be	O
on	O
the	O
same	O
node	O
(	O
usually	O
for	O
testing	O
purposes	O
)	O
,	O
but	O
in	O
typical	O
production	O
installations	O
these	O
devices	O
are	O
on	O
separate	O
nodes	O
communicating	O
over	O
a	O
network	O
.	O
</s>
<s>
Each	O
MDT	O
and	O
OST	O
may	O
be	O
part	O
of	O
only	O
a	O
single	O
filesystem	B-Application
,	O
though	O
it	O
is	O
possible	O
to	O
have	O
multiple	O
MDTs	O
or	O
OSTs	O
on	O
a	O
single	O
node	O
that	O
are	O
part	O
of	O
different	O
filesystems	B-Application
.	O
</s>
<s>
The	O
Lustre	B-Application
Network	O
(	O
LNet	O
)	O
layer	O
can	O
use	O
several	O
types	O
of	O
network	O
interconnects	O
,	O
including	O
native	O
InfiniBand	B-Architecture
verbs	O
,	O
Omni-Path	B-Operating_System
,	O
RoCE	B-Operating_System
,	O
and	O
iWARP	B-Device
via	O
OFED	O
,	O
TCP/IP	B-Protocol
on	O
Ethernet	O
,	O
and	O
other	O
proprietary	O
network	O
technologies	O
such	O
as	O
the	O
Cray	O
Gemini	O
interconnect	O
.	O
</s>
<s>
In	O
Lustre	B-Application
2.3	O
and	O
earlier	O
,	O
Myrinet	B-General_Concept
,	O
Quadrics	B-General_Concept
,	O
Cray	O
SeaStar	O
and	O
RapidArray	O
networks	O
were	O
also	O
supported	O
,	O
but	O
these	O
network	O
drivers	O
were	O
deprecated	O
when	O
these	O
networks	O
were	O
no	O
longer	O
commercially	O
available	O
,	O
and	O
support	O
was	O
removed	O
completely	O
in	O
Lustre	B-Application
2.8	O
.	O
</s>
<s>
Lustre	B-Application
will	O
take	O
advantage	O
of	O
remote	B-General_Concept
direct	I-General_Concept
memory	I-General_Concept
access	I-General_Concept
(	O
RDMA	B-General_Concept
)	O
transfers	O
,	O
when	O
available	O
,	O
to	O
improve	O
throughput	O
and	O
reduce	O
CPU	O
usage	O
.	O
</s>
<s>
The	O
storage	O
used	O
for	O
the	O
MDT	O
and	O
OST	O
backing	O
filesystems	B-Application
is	O
normally	O
provided	O
by	O
hardware	O
RAID	B-Architecture
devices	O
,	O
though	O
will	O
work	O
with	O
any	O
block	O
devices	O
.	O
</s>
<s>
Since	O
Lustre	B-Application
2.4	O
,	O
the	O
MDT	O
and	O
OST	O
can	O
also	O
use	O
ZFS	B-Application
for	O
the	O
backing	O
filesystem	B-Application
in	O
addition	O
to	O
ext4	B-Application
,	O
allowing	O
them	O
to	O
effectively	O
use	O
JBOD	O
storage	O
instead	O
of	O
hardware	O
RAID	B-Architecture
devices	O
.	O
</s>
<s>
The	O
Lustre	B-Application
OSS	O
and	O
MDS	O
servers	O
read	O
,	O
write	O
,	O
and	O
modify	O
data	O
in	O
the	O
format	O
imposed	O
by	O
the	O
backing	O
filesystem	B-Application
and	O
return	O
this	O
data	O
to	O
the	O
clients	O
.	O
</s>
<s>
This	O
allows	O
Lustre	B-Application
to	O
take	O
advantage	O
of	O
improvements	O
and	O
features	O
in	O
the	O
underlying	O
filesystem	B-Application
,	O
such	O
as	O
compression	O
and	O
data	O
checksums	O
in	O
ZFS	B-Application
.	O
</s>
<s>
Clients	O
do	O
not	O
have	O
any	O
direct	O
access	O
to	O
the	O
underlying	O
storage	O
,	O
which	O
ensures	O
that	O
a	O
malfunctioning	O
or	O
malicious	O
client	B-Protocol
cannot	O
corrupt	O
the	O
filesystem	B-Application
structure	O
.	O
</s>
<s>
An	O
OST	O
is	O
a	O
dedicated	O
filesystem	B-Application
that	O
exports	O
an	O
interface	O
to	O
byte	O
ranges	O
of	O
file	O
objects	O
for	O
read/write	O
operations	O
,	O
with	O
extent	B-Application
locks	O
to	O
protect	O
data	O
consistency	O
.	O
</s>
<s>
An	O
MDT	O
is	O
a	O
dedicated	O
filesystem	B-Application
that	O
stores	O
inodes	B-Application
,	O
directories	O
,	O
POSIX	O
and	O
extended	B-Application
file	I-Application
attributes	I-Application
,	O
controls	O
file	B-Application
access	I-Application
permissions/ACLs	O
,	O
and	O
tells	O
clients	O
the	O
layout	O
of	O
the	O
object(s )	O
that	O
make	O
up	O
each	O
regular	O
file	O
.	O
</s>
<s>
MDTs	O
and	O
OSTs	O
currently	O
use	O
either	O
an	O
enhanced	O
version	O
of	O
ext4	B-Application
called	O
ldiskfs	B-Application
,	O
or	O
ZFS/DMU	O
for	O
back-end	O
data	O
storage	O
to	O
store	O
files/objects	O
using	O
the	O
open	O
source	O
ZFS-on-Linux	O
port	O
.	O
</s>
<s>
The	O
client	B-Protocol
mounts	O
the	O
Lustre	B-Application
filesystem	B-Application
locally	O
with	O
a	O
VFS	B-Application
driver	O
for	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
that	O
connects	O
the	O
client	B-Protocol
to	O
the	O
server(s )	O
.	O
</s>
<s>
Upon	O
initial	O
mount	O
,	O
the	O
client	B-Protocol
is	O
provided	O
a	O
File	O
Identifier	O
(	O
FID	O
)	O
for	O
the	O
root	B-Application
directory	I-Application
of	O
the	O
mountpoint	O
.	O
</s>
<s>
When	O
the	O
client	B-Protocol
accesses	O
a	O
file	O
,	O
it	O
performs	O
a	O
filename	O
lookup	O
on	O
the	O
MDS	O
.	O
</s>
<s>
When	O
the	O
MDS	O
filename	O
lookup	O
is	O
complete	O
and	O
the	O
user	O
and	O
client	B-Protocol
have	O
permission	O
to	O
access	O
and/or	O
create	O
the	O
file	O
,	O
either	O
the	O
layout	O
of	O
an	O
existing	O
file	O
is	O
returned	O
to	O
the	O
client	B-Protocol
or	O
a	O
new	O
file	O
is	O
created	O
on	O
behalf	O
of	O
the	O
client	B-Protocol
,	O
if	O
requested	O
.	O
</s>
<s>
For	O
read	O
or	O
write	O
operations	O
,	O
the	O
client	B-Protocol
then	O
interprets	O
the	O
file	O
layout	O
in	O
the	O
logical	O
object	O
volume	O
(	O
LOV	O
)	O
layer	O
,	O
which	O
maps	O
the	O
file	O
logical	O
offset	O
and	O
size	O
to	O
one	O
or	O
more	O
objects	O
.	O
</s>
<s>
The	O
client	B-Protocol
then	O
locks	O
the	O
file	O
range	O
being	O
operated	O
on	O
and	O
executes	O
one	O
or	O
more	O
parallel	O
read	O
or	O
write	O
operations	O
directly	O
to	O
the	O
OSS	O
nodes	O
that	O
hold	O
the	O
data	O
objects	O
.	O
</s>
<s>
With	O
this	O
approach	O
,	O
bottlenecks	O
for	O
client-to-OSS	O
communications	O
are	O
eliminated	O
,	O
so	O
the	O
total	O
bandwidth	O
available	O
for	O
the	O
clients	O
to	O
read	O
and	O
write	O
data	O
scales	O
almost	O
linearly	O
with	O
the	O
number	O
of	O
OSTs	O
in	O
the	O
filesystem	B-Application
.	O
</s>
<s>
Clients	O
do	O
not	O
directly	O
modify	O
the	O
objects	O
or	O
data	O
on	O
the	O
OST	O
filesystems	B-Application
,	O
but	O
instead	O
delegate	O
this	O
task	O
to	O
OSS	O
nodes	O
.	O
</s>
<s>
This	O
approach	O
ensures	O
scalability	O
for	O
large-scale	O
clusters	O
and	O
supercomputers	B-Architecture
,	O
as	O
well	O
as	O
improved	O
security	O
and	O
reliability	O
.	O
</s>
<s>
In	O
contrast	O
,	O
shared	O
block-based	O
filesystems	B-Application
such	O
as	O
GPFS	B-Application
and	O
OCFS	B-Application
allow	O
direct	O
access	O
to	O
the	O
underlying	O
storage	O
by	O
all	O
of	O
the	O
clients	O
in	O
the	O
filesystem	B-Application
,	O
which	O
requires	O
a	O
large	O
back-end	O
SAN	O
attached	O
to	O
all	O
clients	O
,	O
and	O
increases	O
the	O
risk	O
of	O
filesystem	B-Application
corruption	O
from	O
misbehaving/defective	O
clients	O
.	O
</s>
<s>
In	O
a	O
typical	O
Lustre	B-Application
installation	O
on	O
a	O
Linux	B-Application
client	B-Protocol
,	O
a	O
Lustre	B-Application
filesystem	B-Application
driver	O
module	O
is	O
loaded	O
into	O
the	O
kernel	B-Operating_System
and	O
the	O
filesystem	B-Application
is	O
mounted	O
like	O
any	O
other	O
local	O
or	O
network	O
filesystem	B-Application
.	O
</s>
<s>
Client	B-Protocol
applications	I-Protocol
see	O
a	O
single	O
,	O
unified	O
filesystem	B-Application
even	O
though	O
it	O
may	O
be	O
composed	O
of	O
tens	O
to	O
thousands	O
of	O
individual	O
servers	O
and	O
MDT/OST	O
filesystems	B-Application
.	O
</s>
<s>
On	O
some	O
massively	B-Operating_System
parallel	I-Operating_System
processor	I-Operating_System
(	O
MPP	O
)	O
installations	O
,	O
computational	O
processors	O
can	O
access	O
a	O
Lustre	B-Application
file	B-Application
system	I-Application
by	O
redirecting	O
their	O
I/O	O
requests	O
to	O
a	O
dedicated	O
I/O	O
node	O
configured	O
as	O
a	O
Lustre	B-Application
client	B-Protocol
.	O
</s>
<s>
This	O
approach	O
is	O
used	O
in	O
the	O
Blue	B-Operating_System
Gene	I-Operating_System
installation	O
at	O
Lawrence	O
Livermore	O
National	O
Laboratory	O
.	O
</s>
<s>
Another	O
approach	O
used	O
in	O
the	O
early	O
years	O
of	O
Lustre	B-Application
is	O
the	O
liblustre	O
library	O
on	O
the	O
Cray	B-Device
XT3	I-Device
using	O
the	O
Catamount	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
on	O
systems	O
such	O
as	O
Sandia	B-Operating_System
Red	I-Operating_System
Storm	I-Operating_System
,	O
which	O
provided	O
userspace	O
applications	O
with	O
direct	O
filesystem	B-Application
access	O
.	O
</s>
<s>
Liblustre	O
was	O
a	O
user-level	O
library	O
that	O
allows	O
computational	O
processors	O
to	O
mount	O
and	O
use	O
the	O
Lustre	B-Application
file	B-Application
system	I-Application
as	O
a	O
client	B-Protocol
.	O
</s>
<s>
Using	O
liblustre	O
,	O
the	O
computational	O
processors	O
could	O
access	O
a	O
Lustre	B-Application
file	B-Application
system	I-Application
even	O
if	O
the	O
service	O
node	O
on	O
which	O
the	O
job	O
was	O
launched	O
is	O
not	O
a	O
Linux	B-Application
client	B-Protocol
.	O
</s>
<s>
Liblustre	O
allowed	O
data	O
movement	O
directly	O
between	O
application	O
space	O
and	O
the	O
Lustre	B-Application
OSSs	O
without	O
requiring	O
an	O
intervening	O
data	O
copy	O
through	O
the	O
kernel	B-Operating_System
,	O
thus	O
providing	O
access	O
from	O
computational	O
processors	O
to	O
the	O
Lustre	B-Application
file	B-Application
system	I-Application
directly	O
in	O
a	O
constrained	O
operating	O
environment	O
.	O
</s>
<s>
The	O
liblustre	O
functionality	O
was	O
deleted	O
from	O
Lustre	B-Application
2.7.0	O
after	O
having	O
been	O
disabled	O
since	O
Lustre	B-Application
2.6.0	O
,	O
and	O
was	O
untested	O
since	O
Lustre	B-Application
2.3.0	O
.	O
</s>
<s>
In	O
Linux	B-Operating_System
Kernel	I-Operating_System
version	O
4.18	O
,	O
the	O
incomplete	O
port	O
of	O
the	O
Lustre	B-Application
client	B-Protocol
was	O
removed	O
from	O
the	O
kernel	B-Operating_System
staging	O
area	O
in	O
order	O
to	O
speed	O
up	O
development	O
and	O
porting	O
to	O
newer	O
kernels	B-Operating_System
.	O
</s>
<s>
The	O
out-of-tree	O
Lustre	B-Application
client	B-Protocol
and	O
server	O
is	O
still	O
available	O
for	O
RHEL	O
,	O
SLES	O
,	O
and	O
Ubuntu	O
distro	O
kernels	B-Operating_System
,	O
as	O
well	O
as	O
vanilla	O
kernels	B-Operating_System
.	O
</s>
<s>
In	O
a	O
traditional	O
Unix	O
disk	B-Application
file	I-Application
system	I-Application
,	O
an	O
inode	B-Application
data	O
structure	O
contains	O
basic	O
information	O
about	O
each	O
file	O
,	O
such	O
as	O
where	O
the	O
data	O
contained	O
in	O
the	O
file	O
is	O
stored	O
.	O
</s>
<s>
The	O
Lustre	B-Application
file	B-Application
system	I-Application
also	O
uses	O
inodes	B-Application
,	O
but	O
inodes	B-Application
on	O
MDTs	O
point	O
to	O
one	O
or	O
more	O
OST	O
objects	O
associated	O
with	O
the	O
file	O
rather	O
than	O
to	O
data	O
blocks	O
.	O
</s>
<s>
When	O
a	O
client	B-Protocol
opens	O
a	O
file	O
,	O
the	O
file	O
open	O
operation	O
transfers	O
a	O
set	O
of	O
object	O
identifiers	O
and	O
their	O
layout	O
from	O
the	O
MDS	O
to	O
the	O
client	B-Protocol
,	O
so	O
that	O
the	O
client	B-Protocol
can	O
directly	O
interact	O
with	O
the	O
OSS	O
node	O
where	O
the	O
object	O
is	O
stored	O
.	O
</s>
<s>
This	O
allows	O
the	O
client	B-Protocol
to	O
perform	O
I/O	O
in	O
parallel	O
across	O
all	O
of	O
the	O
OST	O
objects	O
in	O
the	O
file	O
without	O
further	O
communication	O
with	O
the	O
MDS	O
.	O
</s>
<s>
If	O
only	O
one	O
OST	O
object	O
is	O
associated	O
with	O
an	O
MDT	O
inode	B-Application
,	O
that	O
object	O
contains	O
all	O
the	O
data	O
in	O
the	O
Lustre	B-Application
file	O
.	O
</s>
<s>
When	O
more	O
than	O
one	O
object	O
is	O
associated	O
with	O
a	O
file	O
,	O
data	O
in	O
the	O
file	O
is	O
"	O
striped	O
"	O
in	O
chunks	O
in	O
a	O
round-robin	B-Algorithm
manner	O
across	O
the	O
OST	O
objects	O
similar	O
to	O
RAID	B-Architecture
0	O
in	O
chunks	O
typically	O
1MB	O
or	O
larger	O
.	O
</s>
<s>
Each	O
file	O
created	O
in	O
the	O
filesystem	B-Application
may	O
specify	O
different	O
layout	O
parameters	O
,	O
such	O
as	O
the	O
stripe	O
count	O
(	O
number	O
of	O
OST	O
objects	O
making	O
up	O
that	O
file	O
)	O
,	O
stripe	O
size	O
(	O
unit	O
of	O
data	O
stored	O
on	O
each	O
OST	O
before	O
moving	O
to	O
the	O
next	O
)	O
,	O
and	O
OST	O
selection	O
,	O
so	O
that	O
performance	O
and	O
capacity	O
can	O
be	O
tuned	O
optimally	O
for	O
each	O
file	O
.	O
</s>
<s>
In	O
the	O
Lustre	B-Application
2.10	O
release	O
,	O
the	O
ability	O
to	O
specify	O
composite	O
layouts	O
was	O
added	O
to	O
allow	O
files	O
to	O
have	O
different	O
layout	O
parameters	O
for	O
different	O
regions	O
of	O
the	O
file	O
.	O
</s>
<s>
The	O
composite	O
layouts	O
are	O
further	O
enhanced	O
in	O
the	O
2.11	O
release	O
with	O
the	O
File	O
Level	O
Redundancy	O
(	O
FLR	O
)	O
feature	O
,	O
which	O
allows	O
a	O
file	O
to	O
have	O
multiple	O
overlapping	O
layouts	O
for	O
a	O
file	O
,	O
providing	O
RAID	B-Architecture
0+1	O
redundancy	O
for	O
these	O
files	O
as	O
well	O
as	O
improved	O
read	O
performance	O
.	O
</s>
<s>
The	O
Lustre	B-Application
2.11	O
release	O
also	O
added	O
the	O
Data-on-Metadata	O
(	O
DoM	O
)	O
feature	O
,	O
which	O
allows	O
the	O
first	O
component	O
of	O
a	O
PFL	O
file	O
to	O
be	O
stored	O
directly	O
on	O
the	O
MDT	O
with	O
the	O
inode	B-Application
.	O
</s>
<s>
DoM	O
also	O
improves	O
performance	O
for	O
small	O
files	O
if	O
the	O
MDT	O
is	O
SSD-based	O
,	O
while	O
the	O
OSTs	O
are	O
disk-based	O
.	O
</s>
<s>
In	O
Lustre	B-Application
2.13	O
the	O
OST	O
Overstriping	O
feature	O
allows	O
a	O
single	O
component	O
to	O
have	O
multiple	O
stripes	O
on	O
one	O
OST	O
,	O
while	O
the	O
Self-Extending	O
Layout	O
feature	O
allows	O
the	O
component	O
size	O
to	O
be	O
dynamic	O
during	O
write	O
so	O
that	O
it	O
can	O
cope	O
with	O
(	O
flash	O
)	O
OSTs	O
running	O
out	O
of	O
space	O
before	O
the	O
whole	O
filesystem	B-Application
is	O
out	O
of	O
space	O
.	O
</s>
<s>
When	O
a	O
client	B-Protocol
initially	O
mounts	O
a	O
filesystem	B-Application
,	O
it	O
is	O
provided	O
the	O
128-bit	O
Lustre	B-Application
File	O
Identifier	O
(	O
FID	O
,	O
composed	O
of	O
the	O
64-bit	O
Sequence	O
number	O
,	O
32-bit	O
Object	O
ID	O
,	O
and	O
32-bit	O
Version	O
)	O
of	O
the	O
root	B-Application
directory	I-Application
for	O
the	O
mountpoint	O
.	O
</s>
<s>
When	O
doing	O
a	O
filename	O
lookup	O
,	O
the	O
client	B-Protocol
performs	O
a	O
lookup	O
of	O
each	O
pathname	O
component	O
by	O
mapping	O
the	O
parent	O
directory	O
FID	O
Sequence	O
number	O
to	O
a	O
specific	O
MDT	O
via	O
the	O
FID	O
Location	O
Database	O
(	O
FLDB	O
)	O
,	O
and	O
then	O
does	O
a	O
lookup	O
on	O
the	O
MDS	O
managing	O
this	O
MDT	O
using	O
the	O
parent	O
FID	O
and	O
filename	O
.	O
</s>
<s>
The	O
Logical	O
Metadata	O
Volume	O
(	O
LMV	O
)	O
on	O
the	O
client	B-Protocol
hashes	O
the	O
filename	O
and	O
maps	O
it	O
to	O
a	O
specific	O
MDT	O
directory	O
shard	B-General_Concept
,	O
which	O
will	O
handle	O
further	O
operations	O
on	O
that	O
file	O
in	O
an	O
identical	O
manner	O
to	O
a	O
non-striped	O
directory	O
.	O
</s>
<s>
For	O
readdir( )	O
operations	O
,	O
the	O
entries	O
from	O
each	O
directory	O
shard	B-General_Concept
are	O
returned	O
to	O
the	O
client	B-Protocol
sorted	O
in	O
the	O
local	O
MDT	O
directory	O
hash	O
order	O
,	O
and	O
the	O
client	B-Protocol
performs	O
a	O
merge	O
sort	O
to	O
interleave	O
the	O
filenames	O
in	O
hash	O
order	O
so	O
that	O
a	O
single	O
64-bit	O
cookie	O
can	O
be	O
used	O
to	O
determine	O
the	O
current	O
offset	O
within	O
the	O
directory	O
.	O
</s>
<s>
The	O
Lustre	B-Application
distributed	B-Operating_System
lock	I-Operating_System
manager	I-Operating_System
(	O
LDLM	O
)	O
,	O
implemented	O
in	O
the	O
OpenVMS	B-Operating_System
style	O
,	O
protects	O
the	O
integrity	O
of	O
each	O
file	O
's	O
data	O
and	O
metadata	O
.	O
</s>
<s>
Access	O
and	O
modification	O
of	O
a	O
Lustre	B-Application
file	O
is	O
completely	O
cache	B-General_Concept
coherent	I-General_Concept
among	O
all	O
of	O
the	O
clients	O
.	O
</s>
<s>
Metadata	O
locks	O
are	O
managed	O
by	O
the	O
MDT	O
that	O
stores	O
the	O
inode	B-Application
for	O
the	O
file	O
,	O
using	O
FID	O
as	O
the	O
resource	O
name	O
.	O
</s>
<s>
The	O
metadata	O
locks	O
are	O
split	O
into	O
separate	O
bits	O
that	O
protect	O
the	O
lookup	O
of	O
the	O
file	O
(	O
file	O
owner	O
and	O
group	O
,	O
permission	O
and	O
mode	O
,	O
and	O
access	O
control	O
list	O
(	O
ACL	O
)	O
)	O
,	O
the	O
state	O
of	O
the	O
inode	B-Application
(	O
directory	O
size	O
,	O
directory	O
contents	O
,	O
link	O
count	O
,	O
timestamps	O
)	O
,	O
layout	O
(	O
file	O
striping	O
,	O
since	O
Lustre	B-Application
2.4	O
)	O
,	O
and	O
extended	B-Application
attributes	I-Application
(	O
xattrs	B-Application
,	O
since	O
Lustre	B-Application
2.5	O
)	O
.	O
</s>
<s>
A	O
client	B-Protocol
can	O
fetch	O
multiple	O
metadata	O
lock	O
bits	O
for	O
a	O
single	O
inode	B-Application
with	O
a	O
single	O
RPC	O
request	O
,	O
but	O
currently	O
they	O
are	O
only	O
ever	O
granted	O
a	O
read	O
lock	O
for	O
the	O
inode	B-Application
.	O
</s>
<s>
The	O
MDS	O
manages	O
all	O
modifications	O
to	O
the	O
inode	B-Application
in	O
order	O
to	O
avoid	O
lock	O
resource	B-General_Concept
contention	I-General_Concept
and	O
is	O
currently	O
the	O
only	O
node	O
that	O
gets	O
write	O
locks	O
on	O
inodes	B-Application
.	O
</s>
<s>
File	O
data	O
locks	O
are	O
managed	O
by	O
the	O
OST	O
on	O
which	O
each	O
object	O
of	O
the	O
file	O
is	O
striped	O
,	O
using	O
byte-range	O
extent	B-Application
locks	O
.	O
</s>
<s>
Clients	O
can	O
be	O
granted	O
overlapping	O
read	O
extent	B-Application
locks	O
for	O
part	O
or	O
all	O
of	O
the	O
file	O
,	O
allowing	O
multiple	O
concurrent	O
readers	O
of	O
the	O
same	O
file	O
,	O
and/or	O
non-overlapping	O
write	O
extent	B-Application
locks	O
for	O
independent	O
regions	O
of	O
the	O
file	O
.	O
</s>
<s>
This	O
allows	O
many	O
Lustre	B-Application
clients	O
to	O
access	O
a	O
single	O
file	O
concurrently	O
for	O
both	O
read	O
and	O
write	O
,	O
avoiding	O
bottlenecks	O
during	O
file	O
I/O	O
.	O
</s>
<s>
In	O
practice	O
,	O
because	O
Linux	B-Application
clients	O
manage	O
their	O
data	O
cache	O
in	O
units	O
of	O
pages	B-General_Concept
,	O
the	O
clients	O
will	O
request	O
locks	O
that	O
are	O
always	O
an	O
integer	O
multiple	O
of	O
the	O
page	B-General_Concept
size	I-General_Concept
(	O
4096	O
bytes	O
on	O
most	O
clients	O
)	O
.	O
</s>
<s>
When	O
a	O
client	B-Protocol
is	O
requesting	O
an	O
extent	B-Application
lock	O
the	O
OST	O
may	O
grant	O
a	O
lock	O
for	O
a	O
larger	O
extent	B-Application
than	O
originally	O
requested	O
,	O
in	O
order	O
to	O
reduce	O
the	O
number	O
of	O
lock	O
requests	O
that	O
the	O
client	B-Protocol
makes	O
.	O
</s>
<s>
The	O
actual	O
size	O
of	O
the	O
granted	O
lock	O
depends	O
on	O
several	O
factors	O
,	O
including	O
the	O
number	O
of	O
currently	O
granted	O
locks	O
on	O
that	O
object	O
,	O
whether	O
there	O
are	O
conflicting	O
write	O
locks	O
for	O
the	O
requested	O
lock	O
extent	B-Application
,	O
and	O
the	O
number	O
of	O
pending	O
lock	O
requests	O
on	O
that	O
object	O
.	O
</s>
<s>
The	O
granted	O
lock	O
is	O
never	O
smaller	O
than	O
the	O
originally	O
requested	O
extent	B-Application
.	O
</s>
<s>
OST	O
extent	B-Application
locks	O
use	O
the	O
Lustre	B-Application
FID	O
of	O
the	O
object	O
as	O
the	O
resource	O
name	O
for	O
the	O
lock	O
.	O
</s>
<s>
Since	O
the	O
number	O
of	O
extent	B-Application
lock	O
servers	O
scales	O
with	O
the	O
number	O
of	O
OSTs	O
in	O
the	O
filesystem	B-Application
,	O
this	O
also	O
scales	O
the	O
aggregate	O
locking	O
performance	O
of	O
the	O
filesystem	B-Application
,	O
and	O
of	O
a	O
single	O
file	O
if	O
it	O
is	O
striped	O
over	O
multiple	O
OSTs	O
.	O
</s>
<s>
The	O
communication	O
between	O
the	O
Lustre	B-Application
clients	O
and	O
servers	O
is	O
implemented	O
using	O
Lustre	B-Application
Networking	O
(	O
LNet	O
)	O
,	O
which	O
was	O
originally	O
based	O
on	O
the	O
Sandia	O
Portals	B-Operating_System
network	I-Operating_System
programming	I-Operating_System
application	I-Operating_System
programming	I-Operating_System
interface	I-Operating_System
.	O
</s>
<s>
Disk	O
storage	O
is	O
connected	O
to	O
the	O
Lustre	B-Application
MDS	O
and	O
OSS	O
server	O
nodes	O
using	O
direct	O
attached	O
storage	O
(	O
SAS	O
,	O
FC	B-Architecture
,	O
iSCSI	B-Protocol
)	O
or	O
traditional	O
storage	O
area	O
network	O
(	O
SAN	O
)	O
technologies	O
,	O
which	O
is	O
independent	O
of	O
the	O
client-to-server	O
network	O
.	O
</s>
<s>
LNet	O
can	O
use	O
many	O
commonly	O
used	O
network	O
types	O
,	O
such	O
as	O
InfiniBand	B-Architecture
and	O
TCP	O
(	O
commonly	O
Ethernet	O
)	O
networks	O
,	O
and	O
allows	O
simultaneous	O
availability	O
across	O
multiple	O
network	O
types	O
with	O
routing	O
between	O
them	O
.	O
</s>
<s>
Remote	B-General_Concept
Direct	I-General_Concept
Memory	I-General_Concept
Access	I-General_Concept
(	O
RDMA	B-General_Concept
)	O
is	O
used	O
for	O
data	O
and	O
metadata	O
transfer	O
between	O
nodes	O
when	O
provided	O
by	O
the	O
underlying	O
networks	O
,	O
such	O
as	O
InfiniBand	B-Architecture
,	O
RoCE	B-Operating_System
,	O
iWARP	B-Device
,	O
and	O
Omni-Path	B-Operating_System
,	O
as	O
well	O
as	O
proprietary	O
high-speed	O
networks	O
such	O
as	O
Cray	O
Aries	O
and	O
Gemini	O
,	O
and	O
Atos	O
BXI	O
.	O
</s>
<s>
allows	O
link	B-Architecture
aggregation	I-Architecture
of	O
two	O
or	O
more	O
network	O
interfaces	O
between	O
a	O
client	B-Protocol
and	O
server	O
to	O
improve	O
bandwidth	O
.	O
</s>
<s>
LNet	O
provides	O
end-to-end	O
throughput	O
over	O
Gigabit	O
Ethernet	O
networks	O
in	O
excess	O
of	O
100MB/s	O
,	O
throughput	O
up	O
to	O
11	O
GB/s	O
using	O
InfiniBand	B-Architecture
enhanced	O
data	O
rate	O
(	O
EDR	O
)	O
links	O
,	O
and	O
throughput	O
over	O
11GB/s	O
across	O
100	B-Protocol
Gigabit	I-Protocol
Ethernet	I-Protocol
interfaces	O
.	O
</s>
<s>
Lustre	B-Application
file	B-Application
system	I-Application
high	O
availability	O
features	O
include	O
a	O
robust	O
failover	O
and	O
recovery	O
mechanism	O
,	O
making	O
server	O
failures	O
and	O
reboots	O
transparent	O
.	O
</s>
<s>
Version	O
interoperability	O
between	O
successive	O
minor	O
versions	O
of	O
the	O
Lustre	B-Application
software	O
enables	O
a	O
server	O
to	O
be	O
upgraded	O
by	O
taking	O
it	O
offline	O
(	O
or	O
failing	O
it	O
over	O
to	O
a	O
standby	O
server	O
)	O
,	O
performing	O
the	O
upgrade	O
,	O
and	O
restarting	O
it	O
,	O
while	O
all	O
active	O
jobs	O
continue	O
to	O
run	O
,	O
experiencing	O
a	O
delay	O
while	O
the	O
backup	O
server	O
takes	O
over	O
the	O
storage	O
.	O
</s>
<s>
Lustre	B-Application
MDSes	O
are	O
configured	O
as	O
an	O
active/passive	O
pair	O
exporting	O
a	O
single	O
MDT	O
,	O
or	O
one	O
or	O
more	O
active/active	O
MDS	O
pairs	O
with	O
DNE	O
exporting	O
two	O
or	O
more	O
separate	O
MDTs	O
,	O
while	O
OSSes	O
are	O
typically	O
deployed	O
in	O
an	O
active/active	O
configuration	O
exporting	O
separate	O
OSTs	O
to	O
provide	O
redundancy	O
without	O
extra	O
system	O
overhead	O
.	O
</s>
<s>
In	O
single-MDT	O
filesystems	B-Application
,	O
the	O
standby	O
MDS	O
for	O
one	O
filesystem	B-Application
is	O
the	O
MGS	O
and/or	O
monitoring	O
node	O
,	O
or	O
the	O
active	O
MDS	O
for	O
another	O
file	B-Application
system	I-Application
,	O
so	O
no	O
nodes	O
are	O
idle	O
in	O
the	O
cluster	B-Architecture
.	O
</s>
<s>
Lustre	B-Application
provides	O
the	O
capability	O
to	O
have	O
multiple	O
storage	O
tiers	O
within	O
a	O
single	O
filesystem	B-Application
namespace	O
.	O
</s>
<s>
It	O
allows	O
traditional	O
HSM	B-Application
functionality	O
to	O
copy	O
(	O
archive	O
)	O
files	O
off	O
the	O
primary	O
filesystem	B-Application
to	O
a	O
secondary	O
archive	O
storage	O
tier	O
.	O
</s>
<s>
Once	O
a	O
file	O
is	O
archived	O
,	O
it	O
can	O
be	O
released	O
from	O
the	O
main	O
filesystem	B-Application
,	O
leaving	O
only	O
a	O
stub	O
that	O
references	O
the	O
archive	O
copy	O
.	O
</s>
<s>
In	O
addition	O
to	O
external	O
storage	O
tiering	O
,	O
it	O
is	O
possible	O
to	O
have	O
multiple	O
storage	O
tiers	O
within	O
a	O
single	O
filesystem	B-Application
namespace	O
.	O
</s>
<s>
HDD	O
and	O
SSD	B-Device
)	O
can	O
be	O
declared	O
in	O
named	O
storage	O
pools	O
.	O
</s>
<s>
Since	O
Lustre	B-Application
2.11	O
,	O
it	O
is	O
also	O
possible	O
to	O
mirror	O
a	O
file	O
to	O
different	O
OST	O
pools	O
with	O
a	O
FLR	O
file	O
layout	O
,	O
for	O
example	O
to	O
pre-stage	O
files	O
into	O
flash	O
for	O
a	O
computing	O
job	O
.	O
</s>
<s>
HSM	B-Application
includes	O
some	O
additional	O
Lustre	B-Application
components	O
to	O
manage	O
the	O
interface	O
between	O
the	O
primary	O
filesystem	B-Application
and	O
the	O
archive	O
:	O
</s>
<s>
Copytools	O
are	O
also	O
available	O
for	O
the	O
High	B-Application
Performance	I-Application
Storage	I-Application
System	I-Application
(	O
HPSS	O
)	O
,	O
Tivoli	B-General_Concept
Storage	I-General_Concept
Manager	I-General_Concept
(	O
TSM	O
)	O
,	O
Amazon	B-General_Concept
S3	I-General_Concept
,	O
and	O
Google	B-Application
Drive	I-Application
.	O
</s>
<s>
Policy	O
Engine	O
:	O
watches	O
filesystem	B-Application
Changelogs	O
for	O
new	O
files	O
to	O
archive	O
,	O
applies	O
policies	O
to	O
release	O
files	O
based	O
on	O
age	O
or	O
space	O
usage	O
,	O
and	O
communicates	O
with	O
MDT	O
and	O
Coordinator	O
.	O
</s>
<s>
HSM	B-Application
also	O
defines	O
new	O
states	O
for	O
files	O
including	O
:	O
</s>
<s>
Exist	O
:	O
Some	O
copy	O
,	O
possibly	O
incomplete	O
exists	O
in	O
a	O
HSM	B-Application
.	O
</s>
<s>
Archive	O
:	O
A	O
full	O
copy	O
exists	O
on	O
the	O
archive	O
side	O
of	O
the	O
HSM	B-Application
.	O
</s>
<s>
Released	O
:	O
A	O
stub	O
inode	B-Application
exists	O
on	O
an	O
MDT	O
,	O
but	O
the	O
data	O
objects	O
have	O
been	O
removed	O
and	O
the	O
only	O
copy	O
exists	O
in	O
the	O
archive	O
.	O
</s>
<s>
Lustre	B-Application
is	O
used	O
by	O
many	O
of	O
the	O
TOP500	B-Operating_System
supercomputers	B-Architecture
and	O
large	O
multi-cluster	O
sites	O
.	O
</s>
<s>
Six	O
of	O
the	O
top	O
10	O
and	O
more	O
than	O
60	O
of	O
the	O
top	O
100	O
supercomputers	B-Architecture
use	O
Lustre	B-Application
file	B-Application
systems	I-Application
.	O
</s>
<s>
These	O
include	O
the	O
700TB	O
5GB/s	O
Orion	O
filesystem	B-Application
for	O
the	O
Frontier	B-Device
supercomputer	I-Device
at	O
Oak	O
Ridge	O
National	O
Laboratory	O
(	O
ORNL	O
)	O
,	O
</s>
<s>
Fugaku	B-Device
and	O
K	B-Device
Computer	I-Device
at	O
the	O
RIKEN	O
Advanced	O
Institute	O
for	O
Computational	O
Science	O
,	O
Tianhe-1A	O
at	O
the	O
National	B-Device
Supercomputing	I-Device
Center	I-Device
in	O
Tianjin	O
,	O
China	O
,	O
LUMI	B-Device
at	O
CSC	O
,	O
Jaguar	B-Device
and	O
Titan	B-Device
at	O
ORNL	O
,	O
Blue	B-Device
Waters	I-Device
at	O
the	O
University	O
of	O
Illinois	O
,	O
and	O
Sequoia	B-Device
and	O
Blue	B-Operating_System
Gene/L	I-Operating_System
at	O
Lawrence	O
Livermore	O
National	O
Laboratory	O
(	O
LLNL	O
)	O
.	O
</s>
<s>
There	O
are	O
also	O
large	O
Lustre	B-Application
filesystems	B-Application
at	O
the	O
National	O
Energy	O
Research	O
Scientific	O
Computing	O
Center	O
,	O
Pacific	O
Northwest	O
National	O
Laboratory	O
,	O
Texas	O
Advanced	O
Computing	O
Center	O
,	O
Brazilian	O
National	O
Laboratory	O
of	O
Scientific	O
Computing	O
,	O
and	O
NASA	O
in	O
North	O
America	O
,	O
in	O
Asia	O
at	O
Tokyo	O
Institute	O
of	O
Technology	O
,	O
in	O
Europe	O
at	O
CEA	O
,	O
and	O
many	O
others	O
.	O
</s>
<s>
Commercial	O
technical	O
support	O
for	O
Lustre	B-Application
is	O
often	O
bundled	O
along	O
with	O
the	O
computing	O
system	O
or	O
storage	O
hardware	O
sold	O
by	O
the	O
vendor	O
.	O
</s>
<s>
Vendors	O
selling	O
storage	O
hardware	O
with	O
bundled	O
Lustre	B-Application
support	O
include	O
Hitachi	O
Data	O
Systems	O
(	O
2012	O
)	O
,	O
DataDirect	O
Networks	O
(	O
DDN	O
)	O
,	O
,	O
and	O
others	O
.	O
</s>
<s>
It	O
is	O
also	O
possible	O
to	O
get	O
software-only	O
support	O
for	O
Lustre	B-Application
file	B-Application
systems	I-Application
from	O
some	O
vendors	O
,	O
including	O
Whamcloud	O
.	O
</s>
<s>
Amazon	B-Application
Web	I-Application
Services	I-Application
offers	O
Amazon	O
FSx	O
for	O
Lustre	B-Application
,	O
a	O
fully	O
managed	O
service	O
,	O
making	O
it	O
easy	O
to	O
launch	O
and	O
run	O
high-performance	O
file	B-Application
systems	I-Application
cost	O
effectively	O
in	O
their	O
cloud	O
.	O
</s>
