<s>
MOSIX	B-Operating_System
is	O
a	O
proprietary	B-Application
distributed	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
.	O
</s>
<s>
Although	O
early	O
versions	O
were	O
based	O
on	O
older	O
UNIX	B-Application
systems	I-Application
,	O
since	O
1999	O
it	O
focuses	O
on	O
Linux	B-Architecture
clusters	I-Architecture
and	O
grids	O
.	O
</s>
<s>
In	O
a	O
MOSIX	B-Operating_System
cluster/grid	O
there	O
is	O
no	O
need	O
to	O
modify	O
or	O
to	O
link	O
applications	O
with	O
any	O
library	O
,	O
to	O
copy	O
files	O
or	O
login	O
to	O
remote	O
nodes	O
,	O
or	O
even	O
to	O
assign	O
processes	O
to	O
different	O
nodes	O
–	O
it	O
is	O
all	O
done	O
automatically	O
,	O
like	O
in	O
an	O
SMP	B-Operating_System
.	O
</s>
<s>
MOSIX	B-Operating_System
has	O
been	O
researched	O
and	O
developed	O
at	O
The	O
Hebrew	O
University	O
of	O
Jerusalem	O
by	O
the	O
research	O
team	O
of	O
Prof	O
.	O
Amnon	O
Barak	O
.	O
</s>
<s>
The	O
first	O
version	O
,	O
called	O
MOS	O
,	O
for	O
Multicomputer	O
OS	O
,	O
(	O
1981	O
–	O
83	O
)	O
was	O
based	O
on	O
Bell	O
Lab	O
's	O
Seventh	B-Operating_System
Edition	I-Operating_System
Unix	I-Operating_System
and	O
ran	O
on	O
a	O
cluster	B-Architecture
of	O
PDP-11	B-Device
computers	O
.	O
</s>
<s>
Later	O
versions	O
were	O
based	O
on	O
Unix	B-Operating_System
System	I-Operating_System
V	I-Operating_System
Release	O
2	O
(	O
1987	O
–	O
89	O
)	O
and	O
ran	O
on	O
a	O
cluster	B-Architecture
of	O
VAX	B-Device
and	O
NS32332-based	O
computers	O
,	O
followed	O
by	O
a	O
BSD/OS	B-Operating_System
-derived	O
version	O
(	O
1991	O
–	O
93	O
)	O
for	O
a	O
cluster	B-Architecture
of	O
486/Pentium	O
computers	O
.	O
</s>
<s>
Since	O
1999	O
MOSIX	B-Operating_System
is	O
tuned	O
to	O
Linux	B-Application
for	O
x86	B-Operating_System
platforms	O
.	O
</s>
<s>
The	O
second	O
version	O
of	O
MOSIX	B-Operating_System
,	O
called	O
MOSIX2	O
,	O
compatible	O
with	O
Linux-2.6	O
and	O
3.0	O
kernels	B-Operating_System
.	O
</s>
<s>
MOSIX2	O
is	O
implemented	O
as	O
an	O
OS	O
virtualization	B-Application
layer	O
that	O
provides	O
users	O
and	O
applications	O
with	O
a	O
single	B-Operating_System
system	I-Operating_System
image	I-Operating_System
with	O
the	O
Linux	B-Application
run-time	O
environment	O
.	O
</s>
<s>
Users	O
run	O
their	O
regular	O
(	O
sequential	O
and	O
parallel	O
)	O
applications	O
while	O
MOSIX	B-Operating_System
transparently	O
and	O
automatically	O
seek	O
resources	O
and	O
migrate	O
processes	O
among	O
nodes	O
to	O
improve	O
the	O
overall	O
performance	O
.	O
</s>
<s>
MOSIX2	O
can	O
manage	O
a	O
cluster	B-Architecture
and	O
a	O
multicluster	O
(	O
grid	B-Architecture
)	O
as	O
well	O
as	O
workstations	O
and	O
other	O
shared	O
resources	O
.	O
</s>
<s>
Flexible	O
management	O
of	O
a	O
grid	B-Architecture
allows	O
owners	O
of	O
clusters	B-Architecture
to	O
share	O
their	O
computational	O
resources	O
,	O
while	O
still	O
preserving	O
their	O
autonomy	O
over	O
their	O
own	O
clusters	B-Architecture
and	O
their	O
ability	O
to	O
disconnect	O
their	O
nodes	O
from	O
the	O
grid	B-Architecture
at	O
any	O
time	O
,	O
without	O
disrupting	O
already	O
running	O
programs	O
.	O
</s>
<s>
A	O
MOSIX	B-Operating_System
grid	B-Architecture
can	O
extend	O
indefinitely	O
as	O
long	O
as	O
there	O
is	O
trust	O
between	O
its	O
cluster	B-Architecture
owners	O
.	O
</s>
<s>
This	O
must	O
include	O
guarantees	O
that	O
guest	O
applications	O
will	O
not	O
be	O
modified	O
while	O
running	O
in	O
remote	O
clusters	B-Architecture
and	O
that	O
no	O
hostile	O
computers	O
can	O
be	O
connected	O
to	O
the	O
local	O
network	O
.	O
</s>
<s>
Nowadays	O
these	O
requirements	O
are	O
standard	O
within	O
clusters	B-Architecture
and	O
organizational	O
grids	O
.	O
</s>
<s>
MOSIX2	O
can	O
run	O
in	O
native	B-Language
mode	I-Language
or	O
in	O
a	O
virtual	B-Architecture
machine	I-Architecture
(	O
VM	O
)	O
.	O
</s>
<s>
In	O
native	B-Language
mode	I-Language
,	O
performance	O
is	O
better	O
,	O
but	O
it	O
requires	O
modifications	O
to	O
the	O
base	O
Linux	B-Operating_System
kernel	I-Operating_System
,	O
whereas	O
a	O
VM	O
can	O
run	O
on	O
top	O
of	O
any	O
unmodified	O
operating	O
system	O
that	O
supports	O
virtualization	B-Application
,	O
including	O
Microsoft	B-Application
Windows	I-Application
,	O
Linux	B-Application
and	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
.	O
</s>
<s>
MOSIX2	O
is	O
most	O
suitable	O
for	O
running	O
compute	O
intensive	O
applications	O
with	O
low	O
to	O
moderate	O
amount	O
of	O
input/output	B-General_Concept
(	O
I/O	B-General_Concept
)	O
.	O
</s>
<s>
Tests	O
of	O
MOSIX2	O
show	O
that	O
the	O
performance	O
of	O
several	O
such	O
applications	O
over	O
a	O
1Gbit/s	O
campus	O
grid	B-Architecture
is	O
nearly	O
identical	O
to	O
that	O
of	O
a	O
single	O
cluster	B-Architecture
.	O
</s>
<s>
Provides	O
aspects	O
of	O
a	O
single-system	B-Operating_System
image	I-Operating_System
:	O
</s>
<s>
Load-balancing	B-Application
.	O
</s>
<s>
Migrating	O
processes	O
from	O
slower	O
to	O
faster	O
nodes	O
and	O
from	O
nodes	O
that	O
run	O
out	O
of	O
free	B-Application
memory	O
.	O
</s>
<s>
Live	O
queuing	O
–	O
queued	O
jobs	O
preserve	O
their	O
full	O
generic	O
Linux	B-Application
environment	O
.	O
</s>
<s>
MOSIX	B-Operating_System
is	O
most	O
suitable	O
for	O
running	O
HPC	B-Architecture
applications	O
with	O
low	O
to	O
moderate	O
amount	O
of	O
I/O	B-General_Concept
.	O
</s>
<s>
Tests	O
of	O
MOSIX	B-Operating_System
show	O
that	O
the	O
performance	O
of	O
several	O
such	O
applications	O
over	O
a	O
1Gbit/s	O
campus	O
grid	B-Architecture
is	O
nearly	O
identical	O
to	O
that	O
of	O
a	O
single	O
cluster	B-Architecture
.	O
</s>
<s>
Efficient	O
utilization	O
of	O
grid-wide	O
resources	O
,	O
by	O
automatic	O
resource	O
discovery	O
and	O
load-balancing	B-Application
.	O
</s>
<s>
Running	O
long	O
processes	O
,	O
which	O
are	O
automatically	O
sent	O
to	O
grid	B-Architecture
nodes	O
and	O
are	O
migrated	O
back	O
when	O
these	O
nodes	O
are	O
disconnected	O
from	O
the	O
grid	B-Architecture
.	O
</s>
<s>
Scientific	O
applications	O
–	O
genomic	O
,	O
protein	O
sequences	O
,	O
molecular	O
dynamics	O
,	O
quantum	O
dynamics	O
,	O
nano-technology	O
and	O
other	O
parallel	O
HPC	B-Architecture
applications	O
.	O
</s>
<s>
Engineering	O
applications	O
–	O
CFD	O
,	O
weather	O
forecasting	O
,	O
crash	O
simulations	O
,	O
oil	O
industry	O
,	O
ASIC	O
design	O
,	O
pharmaceutical	O
and	O
other	O
HPC	B-Architecture
applications	O
.	O
</s>
<s>
As	O
of	O
version	O
4	O
,	O
MOSIX	B-Operating_System
does	O
n't	O
require	O
kernel	B-Operating_System
patching	O
.	O
</s>
<s>
After	O
MOSIX	B-Operating_System
became	O
proprietary	B-Application
software	I-Application
in	O
late	O
2001	O
,	O
Moshe	O
Bar	O
forked	B-Application
the	O
last	O
free	B-Application
version	O
and	O
started	O
the	O
openMosix	B-Operating_System
project	O
on	O
February	O
10	O
,	O
2002	O
.	O
</s>
<s>
On	O
July	O
15	O
,	O
2007	O
,	O
Bar	O
decided	O
to	O
end	O
the	O
openMosix	B-Operating_System
project	O
effective	O
March	O
1	O
,	O
2008	O
,	O
claiming	O
that	O
"	O
the	O
increasing	O
power	O
and	O
availability	O
of	O
low	O
cost	O
multi-core	O
processors	O
is	O
rapidly	O
making	O
single-system	B-Operating_System
image	I-Operating_System
(	O
SSI	O
)	O
clustering	O
less	O
of	O
a	O
factor	O
in	O
computing	O
"	O
.	O
</s>
<s>
The	O
LinuxPMI	B-Operating_System
project	O
is	O
continuing	O
development	O
of	O
the	O
former	O
openMosix	B-Operating_System
code	O
.	O
</s>
