<s>
Linux	B-Operating_System
Containers	B-Application
(	O
LXC	B-Application
)	O
is	O
an	O
operating-system-level	B-Application
virtualization	I-Application
method	O
for	O
running	O
multiple	O
isolated	O
Linux	B-Operating_System
systems	O
(	O
containers	B-Application
)	O
on	O
a	O
control	O
host	O
using	O
a	O
single	O
Linux	B-Operating_System
kernel	I-Operating_System
.	O
</s>
<s>
The	O
Linux	B-Operating_System
kernel	I-Operating_System
provides	O
the	O
cgroups	B-Application
functionality	O
that	O
allows	O
limitation	O
and	O
prioritization	O
of	O
resources	O
(	O
CPU	O
,	O
memory	O
,	O
block	O
I/O	O
,	O
network	O
,	O
etc	O
.	O
)	O
</s>
<s>
without	O
the	O
need	O
for	O
starting	O
any	O
virtual	B-Architecture
machines	I-Architecture
,	O
and	O
also	O
the	O
namespace	B-Architecture
isolation	I-Architecture
functionality	O
that	O
allows	O
complete	O
isolation	O
of	O
an	O
application	O
's	O
view	O
of	O
the	O
operating	O
environment	O
,	O
including	O
process	B-Operating_System
trees	O
,	O
networking	B-Architecture
,	O
user	B-Application
IDs	I-Application
and	O
mounted	B-Application
file	B-Application
systems	I-Application
.	O
</s>
<s>
LXC	B-Application
combines	O
the	O
kernel	B-Operating_System
's	O
cgroups	B-Application
and	O
support	O
for	O
isolated	O
namespaces	O
to	O
provide	O
an	O
isolated	O
environment	O
for	O
applications	O
.	O
</s>
<s>
Early	O
versions	O
of	O
Docker	B-Language
used	O
LXC	B-Application
as	O
the	O
container	B-Application
execution	O
driver	O
,	O
though	O
LXC	B-Application
was	O
made	O
optional	O
in	O
v0.9	O
and	O
support	O
was	O
dropped	O
in	O
Docker	B-Language
v1.10	O
.	O
</s>
<s>
References	O
to	O
Linux	B-Operating_System
containers	B-Application
commonly	O
refer	O
to	O
Docker	B-Language
containers	B-Application
running	O
on	O
Linux	B-Operating_System
.	O
</s>
<s>
LXC	B-Application
provides	O
operating	B-Application
system-level	I-Application
virtualization	I-Application
through	O
a	O
virtual	O
environment	O
that	O
has	O
its	O
own	O
process	B-Operating_System
and	O
network	O
space	O
,	O
instead	O
of	O
creating	O
a	O
full-fledged	O
virtual	B-Architecture
machine	I-Architecture
.	O
</s>
<s>
LXC	B-Application
relies	O
on	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
cgroups	B-Application
functionality	O
that	O
was	O
released	O
in	O
version	O
2.6.24	O
.	O
</s>
<s>
It	O
also	O
relies	O
on	O
other	O
kinds	O
of	O
namespace	B-Architecture
isolation	I-Architecture
functionality	O
,	O
which	O
were	O
developed	O
and	O
integrated	O
into	O
the	O
mainline	O
Linux	B-Operating_System
kernel	I-Operating_System
.	O
</s>
<s>
Originally	O
,	O
LXC	B-Application
containers	B-Application
were	O
not	O
as	O
secure	O
as	O
other	O
OS-level	B-Application
virtualization	I-Application
methods	O
such	O
as	O
OpenVZ	B-Language
:	O
in	O
Linux	B-Operating_System
kernels	I-Operating_System
before	O
3.8	O
,	O
the	O
root	B-Application
user	I-Application
of	O
the	O
guest	O
system	O
could	O
run	O
arbitrary	O
code	O
on	O
the	O
host	O
system	O
with	O
root	B-Application
privileges	I-Application
,	O
just	O
as	O
they	O
can	O
in	O
chroot	B-Application
jails	I-Application
.	O
</s>
<s>
Starting	O
with	O
the	O
LXC1.0	O
release	O
,	O
it	O
is	O
possible	O
to	O
run	O
containers	B-Application
as	O
regular	O
users	O
on	O
the	O
host	O
using	O
"	O
unprivileged	O
containers	B-Application
"	O
.	O
</s>
<s>
Unprivileged	O
containers	B-Application
are	O
more	O
limited	O
in	O
that	O
they	O
cannot	O
access	O
hardware	O
directly	O
.	O
</s>
<s>
However	O
,	O
even	O
privileged	O
containers	B-Application
should	O
provide	O
adequate	O
isolation	O
in	O
the	O
LXC1.0	O
security	O
model	O
,	O
if	O
properly	O
configured	O
.	O
</s>
<s>
LXC	B-Application
is	O
similar	O
to	O
other	O
OS-level	B-Application
virtualization	I-Application
technologies	O
on	O
Linux	B-Operating_System
such	O
as	O
OpenVZ	B-Language
and	O
Linux-VServer	B-Application
,	O
as	O
well	O
as	O
those	O
on	O
other	O
operating	O
systems	O
such	O
as	O
FreeBSD	B-Language
jails	I-Language
,	O
AIX	B-Application
Workload	B-Operating_System
Partitions	I-Operating_System
and	O
Solaris	O
Containers	B-Application
.	O
</s>
<s>
In	O
contrast	O
to	O
OpenVZ	B-Language
,	O
LXC	B-Application
works	O
in	O
the	O
vanilla	O
Linux	B-Operating_System
kernel	I-Operating_System
requiring	O
no	O
additional	O
patches	O
to	O
be	O
applied	O
to	O
the	O
kernel	B-Operating_System
sources	O
.	O
</s>
<s>
Version	O
1	O
of	O
LXC	B-Application
,	O
which	O
was	O
released	O
on	O
20	O
February	O
2014	O
as	O
a	O
long-term	O
supported	O
version	O
,	O
was	O
supported	O
for	O
five	O
years	O
.	O
</s>
<s>
LXC	B-Application
3.0	O
will	O
be	O
supported	O
until	O
June	O
1	O
,	O
2023	O
;	O
LXC	B-Application
4.0	O
until	O
June	O
1	O
,	O
2025	O
;	O
and	O
LX	O
5.0	O
until	O
June	O
1	O
,	O
2027	O
.	O
</s>
<s>
LXD	O
is	O
an	O
alternative	O
Linux	B-Operating_System
container	B-Application
manager	O
.	O
</s>
<s>
It	O
is	O
built	O
on	O
top	O
of	O
LXC	B-Application
and	O
aims	O
to	O
provide	O
a	O
better	O
user	O
experience	O
.	O
</s>
