<s>
Proxmox	B-Language
Virtual	I-Language
Environment	I-Language
(	O
Proxmox	O
VE	O
or	O
PVE	O
)	O
is	O
a	O
hyper-converged	B-Architecture
infrastructure	I-Architecture
open-source	B-Application
software	I-Application
.	O
</s>
<s>
It	O
is	O
a	O
hosted	O
hypervisor	B-Operating_System
that	O
can	O
run	O
operating	O
systems	O
including	O
Linux	B-Application
and	O
Windows	O
on	O
x64	B-Device
hardware	O
.	O
</s>
<s>
It	O
is	O
a	O
Debian-based	O
Linux	B-Application
distribution	I-Application
with	O
a	O
modified	O
Ubuntu	B-Operating_System
LTS	I-Operating_System
kernel	B-Operating_System
and	O
allows	O
deployment	O
and	O
management	O
of	O
virtual	B-Architecture
machines	I-Architecture
and	O
containers	B-Application
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
includes	O
a	O
web	O
console	O
and	O
command-line	O
tools	O
,	O
and	O
provides	O
a	O
REST	B-Protocol
API	I-Protocol
for	O
third-party	O
tools	O
.	O
</s>
<s>
Two	O
types	O
of	O
virtualization	O
are	O
supported	O
:	O
container-based	O
with	O
LXC	B-Application
(	O
starting	O
from	O
version	O
4.0	O
replacing	O
OpenVZ	B-Language
used	O
in	O
version	O
up	O
to	O
3.4	O
,	O
included	O
)	O
,	O
and	O
full	O
virtualization	O
with	O
KVM	B-Application
.	O
</s>
<s>
It	O
includes	O
a	O
web-based	B-Application
management	O
interface	O
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
is	O
licensed	O
under	O
the	O
GNU	B-Application
Affero	I-Application
General	I-Application
Public	I-Application
License	I-Application
,	O
version	O
3	O
.	O
</s>
<s>
Development	O
of	O
Proxmox	B-Language
VE	I-Language
started	O
when	O
Dietmar	O
Maurer	O
and	O
Martin	O
Maurer	O
,	O
two	O
Linux	B-Application
developers	O
,	O
found	O
out	O
OpenVZ	B-Language
had	O
no	O
backup	B-Protocol
tool	O
and	O
no	O
management	O
GUI	O
.	O
</s>
<s>
KVM	B-Application
was	O
appearing	O
at	O
the	O
same	O
time	O
in	O
Linux	B-Application
,	O
and	O
was	O
added	O
shortly	O
afterwards	O
.	O
</s>
<s>
It	O
supported	O
container	B-Application
and	O
full	O
virtualization	O
,	O
managed	O
with	O
a	O
web-based	B-Application
user	O
interface	O
similar	O
to	O
other	O
commercial	O
offerings	O
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
is	O
an	O
open-source	B-Application
server	O
virtualization	O
platform	O
to	O
manage	O
two	O
virtualization	O
technologies	O
:	O
Kernel-based	B-Application
Virtual	I-Application
Machine	I-Application
(	O
KVM	B-Application
)	O
for	O
virtual	B-Architecture
machines	I-Architecture
and	O
LXC	B-Application
for	O
containers	B-Application
-	O
with	O
a	O
single	O
web-based	B-Application
interface	O
.	O
</s>
<s>
The	O
source	O
is	O
open	O
,	O
based	O
on	O
the	O
GNU	B-Application
AGPL	I-Application
,	I-Application
v3	I-Application
.	O
</s>
<s>
With	O
a	O
subscription	O
,	O
users	O
get	O
access	O
to	O
an	O
enterprise	O
software	B-Application
repository	I-Application
.	O
</s>
<s>
Since	O
Proxmox	B-Language
VE	I-Language
for	O
Virtual	B-Architecture
Machines	I-Architecture
are	O
using	O
KVM	B-Application
( +QEMU	O
)	O
as	O
hypervisor	B-Operating_System
,	O
it	O
natively	O
(	O
from	O
the	O
GUI	O
)	O
supports	O
many	O
emulated	O
and	O
paravirtualized	O
hardware	O
components	O
such	O
as	O
:	O
</s>
<s>
Support	O
for	O
QEMU	B-Application
guest	O
agent	O
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
also	O
supports	O
PCI	B-Protocol
and	O
USB	B-Protocol
pass-through	O
devices	O
from	O
the	O
physical	O
server	O
.	O
</s>
<s>
Additional	O
options	O
like	O
CPU	O
flags	O
,	O
different	O
type	O
of	O
emulated	O
hardware	O
(	O
that	O
QEMU	B-Application
supports	O
)	O
etc	O
.	O
</s>
<s>
Since	O
Proxmox	B-Language
VE	I-Language
is	O
using	O
KVM	B-Application
in	O
the	O
background	O
,	O
it	O
supports	O
all	O
operating	O
systems	O
that	O
KVM	B-Application
supports	O
for	O
virtual	B-Architecture
machines	I-Architecture
,	O
like	O
:	O
</s>
<s>
Linux	B-Application
:	O
any	O
distribution	O
(	O
Red	O
Hat	O
Enterprise	O
Linux	B-Application
,	O
CentOS	O
,	O
Rocky	O
Linux	B-Application
,	O
Fedora	O
,	O
Oracle	O
Enterprise	O
Linux	B-Application
,	O
Debian	O
,	O
Ubuntu	B-Operating_System
,	O
SUSE	O
Linux	B-Application
Enterprise	O
Server	O
,	O
openSUSE	B-Operating_System
,	O
Gentoo	B-Application
,	O
Arch	O
Linux	B-Application
,	O
...	O
)	O
.	O
</s>
<s>
BSD	B-Operating_System
:	O
FreeBSD	B-Operating_System
,	O
OpenBSD	B-Operating_System
,	O
NetBSD	B-Device
,	O
DragonflyBSD	B-Application
,	O
...	O
</s>
<s>
Solaris	B-Application
(	O
like	O
)	O
:	O
Solaris	B-Application
,	O
OpenSolaris	B-Operating_System
,	O
OpenIndiana	B-Application
,	O
Nexenta	B-Application
Core	I-Application
,	O
...	O
</s>
<s>
Windows	B-Application
:	I-Application
almost	O
any	O
version	O
starting	O
from	O
Windows	B-Application
95	I-Application
(	O
Windows	B-Application
95	I-Application
,	O
Windows	B-Device
NT	I-Device
,	O
Windows	O
98SE	O
,	O
Windows	O
Server	O
2000	O
,	O
Windows	B-Application
2000	I-Application
,	O
Windows	B-Application
XP	I-Application
,	O
Windows	O
Server	O
2003/R2	O
,	O
Windows	B-Application
Vista	I-Application
,	O
Windows	O
Server	O
2008/R2	O
,	O
Windows	O
7/8	O
,	O
Windows	B-Operating_System
10	I-Operating_System
,	O
Windows	B-Device
Server	I-Device
2008R2	I-Device
,	O
Windows	O
Server	O
2012/R2	O
,	O
Windows	B-Application
11	I-Application
)	O
.	O
</s>
<s>
Haiku	B-Language
,	O
ReactOS	B-Application
,	O
Plan	B-Operating_System
9	I-Operating_System
,	O
AROS	B-Application
Research	I-Application
Operating	I-Application
System	I-Application
and	O
macOS	B-Application
.	O
</s>
<s>
In	O
addition	O
it	O
supports	O
:	O
Android	B-Application
,	O
GNU/Hurd	B-Application
(	O
Debian	O
K16	O
)	O
,	O
Minix	B-Application
3.1.2a	I-Application
,	O
together	O
with	O
other	O
operating	O
systems	O
.	O
</s>
<s>
Relating	O
to	O
Linux	B-Application
containers	B-Application
,	O
since	O
Proxmox	B-Language
VE	I-Language
is	O
using	O
LXC	B-Application
Linux	I-Application
containers	I-Application
,	O
it	O
supports	O
any	O
Linux	B-Application
distribution	I-Application
as	O
a	O
Linux	B-Application
container	B-Application
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
also	O
supports	O
so-called	O
nested	O
virtualization	O
,	O
and	O
it	O
refers	O
to	O
the	O
operating	O
mode	O
in	O
which	O
it	O
is	O
possible	O
to	O
run	O
a	O
hypervisor	B-Operating_System
,	O
such	O
as	O
PVE	O
or	O
others	O
(	O
eg	O
.	O
</s>
<s>
VMware	B-Operating_System
ESXi	I-Operating_System
,	O
Microsoft	O
Hyper-V	O
,	O
VirtualBox	B-Operating_System
and	O
others	O
)	O
,	O
inside	O
a	O
virtual	B-Architecture
computer	I-Architecture
,	O
which	O
runs	O
on	O
another	O
hypervisor	B-Operating_System
,	O
instead	O
of	O
on	O
real	O
hardware	O
.	O
</s>
<s>
In	O
other	O
words	O
,	O
you	O
have	O
a	O
hypervisor	B-Operating_System
installed	O
on	O
hardware	O
,	O
which	O
runs	O
a	O
guest	O
hypervisor	B-Operating_System
(	O
as	O
a	O
virtual	B-Architecture
machine	I-Architecture
)	O
,	O
which	O
in	O
turn	O
can	O
run	O
its	O
own	O
virtual	B-Architecture
machines	I-Architecture
.	O
</s>
<s>
It	O
is	O
very	O
useful	O
for	O
testing	O
;	O
for	O
example	O
,	O
if	O
you	O
want	O
to	O
run	O
a	O
new	O
version	O
of	O
Proxmox	B-Language
VE	I-Language
on	O
an	O
existing	O
Proxmox	B-Language
VE	I-Language
server	O
(	O
hypervisor	B-Operating_System
)	O
and	O
test	O
new	O
features	O
inside	O
it	O
and	O
run	O
virtual	B-Architecture
computers	I-Architecture
under	O
it	O
.	O
</s>
<s>
It	O
's	O
the	O
same	O
with	O
other	O
hypervisors	B-Operating_System
(	O
eg	O
.	O
</s>
<s>
VMware	B-Operating_System
ESXi	I-Operating_System
,	O
Microsoft	O
Hyper-V	O
,	O
VirtualBox	B-Operating_System
,	O
etc	O
.	O
)	O
</s>
<s>
that	O
you	O
might	O
just	O
want	O
to	O
run	O
inside	O
Proxmox	B-Language
VE	I-Language
(	O
as	O
a	O
hypervisor	B-Operating_System
)	O
and	O
test	O
something	O
on	O
them	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
test	O
application	O
,	O
it	O
is	O
possible	O
to	O
run	O
virtual	B-Architecture
computers	I-Architecture
within	O
this	O
kind	O
of	O
nested	O
virtualization	O
that	O
can	O
act	O
as	O
hypervisors	B-Operating_System
only	O
when	O
necessary	O
.	O
</s>
<s>
This	O
is	O
specifically	O
the	O
case	O
with	O
some	O
network	B-Protocol
device	O
and	O
network	B-Protocol
emulators	O
,	O
such	O
as	O
:	O
</s>
<s>
GNS3	B-Application
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
use	O
integrated	O
web	B-Application
based	I-Application
management	I-Application
based	O
on	O
cluster	B-Architecture
and	O
Proxmox	B-Language
VE	I-Language
cluster	B-Architecture
filesystem	B-Application
(	O
pmxcfs	O
)	O
.	O
</s>
<s>
It	O
means	O
that	O
there	O
is	O
no	B-Architecture
single	I-Architecture
point	I-Architecture
of	I-Architecture
failure	I-Architecture
in	O
cluster	B-Architecture
,	O
since	O
every	O
node	B-Protocol
(	O
physical	O
host	O
)	O
has	O
all	O
the	O
configuration	O
files	O
stored	O
in	O
database-driver	O
multi	O
master	O
cluster	B-Architecture
wide	O
filesystem	B-Application
,	O
shared	O
among	O
the	O
nodes	O
via	O
corosync	B-Operating_System
.	O
</s>
<s>
Even	O
more	O
,	O
every	O
node	B-Protocol
has	O
all	O
the	O
roles/functions	O
(	O
management/firewall/storage/network/...	O
)	O
needed	O
for	O
work	O
.	O
</s>
<s>
As	O
the	O
cluster	B-Architecture
grows	O
,	O
level	O
of	O
redundancy	O
also	O
grows	O
with	O
them	O
.	O
</s>
<s>
It	O
also	O
means	O
that	O
user	O
can	O
configure	O
anything	O
on	O
any	O
node	B-Protocol
inside	O
the	O
cluster	B-Architecture
,	O
since	O
all	O
the	O
changes	O
are	O
synchronized	O
inside	O
the	O
cluster	B-Architecture
and	O
immediately	O
available	O
to	O
the	O
other	O
nodes	O
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
use	O
bridge	B-Protocol
model	O
by	O
default	O
.	O
</s>
<s>
Bridges	O
are	O
like	O
physical	O
network	B-Protocol
switches	O
that	O
work	O
in	O
OSI	O
layer	O
2	O
(	O
OSI	O
2	O
)	O
,	O
but	O
implemented	O
in	O
software	O
.	O
</s>
<s>
All	O
virtual	B-Architecture
machines	I-Architecture
or	O
Linux	B-Application
containers	B-Application
can	O
share	O
a	O
single	O
bridge	B-Protocol
,	O
or	O
you	O
can	O
create	O
multiple	O
bridges	O
to	O
isolate	O
(	O
segment	O
)	O
the	O
network	B-Protocol
.	O
</s>
<s>
For	O
the	O
bridge	B-Protocol
itself	O
you	O
can	O
choose	O
between	O
Linux	B-Application
native	O
bridge	B-Protocol
and/or	O
Open	B-Language
vSwitch	I-Language
bridge	B-Protocol
.	O
</s>
<s>
In	O
addition	O
to	O
that	O
you	O
can	O
also	O
natively	O
use	O
a	O
bond	B-Architecture
(	O
aggregation	O
)	O
:	O
Linux	B-Application
native	O
or	O
Open	B-Language
vSwitch	I-Language
kind	O
,	O
with	O
the	O
mode	O
that	O
is	O
best	O
suited	O
for	O
you	O
(	O
e.g.	O
</s>
<s>
balance-rr	O
,	O
active-backup	O
,	O
balance-xor	O
,	O
broadcast	O
,	O
LACP	O
,	O
balance-tlb	O
,	O
balance-alb	O
)	O
.	O
</s>
<s>
All	O
of	O
the	O
above	O
interfaces	O
support	O
VLANs	B-General_Concept
(	O
802.1Q	O
)	O
.	O
</s>
<s>
There	O
is	O
an	O
additional	O
SDN	O
module	O
(	O
currently	O
in	O
testing	O
in	O
v.7.2.x	O
)	O
with	O
which	O
you	O
can	O
utilize	O
:	O
VLAN	B-General_Concept
,	O
QinQ	O
,	O
VxLAN	B-Protocol
and	O
EVPN	B-Protocol
for	O
network	B-Protocol
isolation/segmentation	O
,	O
among	O
the	O
other	O
options	O
specific	O
to	O
the	O
SDN	O
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
supports	O
flexible	O
local	O
and	O
remote	O
(	O
network	B-Protocol
)	O
storages	O
.	O
</s>
<s>
LVM	B-Application
group	O
,	O
LVM-Thin	B-Application
,	O
directory	O
,	O
ZFS	B-Application
and	O
Btrfs	B-Operating_System
.	O
</s>
<s>
Supported	O
remote	O
(	O
network	B-Protocol
)	O
storage	O
types	O
are	O
:	O
</s>
<s>
iSCSI	B-Protocol
,	O
Fibre	B-Architecture
Channel	I-Architecture
,	O
NFS	B-Protocol
,	O
GlusterFS	B-Application
,	O
SMB/CIFS	B-Operating_System
,	O
ZFS	B-Application
over	O
iSCSI	B-Protocol
,	O
Ceph	B-Operating_System
(	O
Ceph	B-Operating_System
FS	O
and/or	O
RBD	O
)	O
and	O
Proxmox	B-Application
Backup	I-Application
Server	I-Application
.	O
</s>
<s>
File	O
level	O
storage	O
-	O
which	O
allow	O
access	O
to	O
fully	O
featured	O
POSIX	O
compliant	O
filesystem	B-Application
.	O
</s>
<s>
Even	O
more	O
,	O
there	O
is	O
a	O
need	O
(	O
and	O
possibilities	O
)	O
to	O
define	O
the	O
type	O
of	O
the	O
storage	O
(	O
for	O
each	O
and	O
every	O
storage	O
)	O
,	O
depending	O
on	O
the	O
usage	O
of	O
the	O
specific	O
storage	O
(	O
for	O
storing	O
the	O
VM/Container	O
disk	O
images	O
,	O
ISO	O
images	O
,	O
LXC	B-Application
templates	O
,	O
backups	B-Protocol
,	O
etc	O
)	O
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
supports	O
redundancy	O
for	O
guests	O
that	O
are	O
using	O
the	O
local	O
storage	O
in	O
the	O
way	O
that	O
it	O
can	O
replicate	O
guest	O
volumes	O
to	O
another	O
PVE	O
node	B-Protocol
(	O
host	O
)	O
using	O
the	O
method	O
so	O
called	O
storage	O
replication	O
(	O
available	O
only	O
for	O
ZFS	B-Application
)	O
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
(	O
PVE	O
)	O
can	O
be	O
clustered	O
across	O
multiple	O
server	O
nodes	O
.	O
</s>
<s>
Official	O
documentation	O
guarantees/tested	O
the	O
cluster	B-Architecture
size	O
of	O
up	O
to	O
32	O
physical	O
servers	O
(	O
nodes	O
)	O
,	O
no	O
matter	O
the	O
CPU	O
core	O
number	O
or	O
any	O
other	O
hardware	O
limitations	O
,	O
but	O
even	O
bigger	O
cluster	B-Architecture
size	O
is	O
possible	O
.	O
</s>
<s>
Those	O
limitation	O
are	O
not	O
imposed	O
by	O
PVE	O
itself	O
,	O
but	O
come	O
from	O
Corosync	B-Operating_System
limits	O
.	O
</s>
<s>
Since	O
version	O
2.0	O
,	O
Proxmox	B-Language
VE	I-Language
offers	O
a	O
high	O
availability	O
option	O
for	O
clusters	O
based	O
on	O
the	O
Corosync	B-Operating_System
communication	O
stack	O
.	O
</s>
<s>
Starting	O
from	O
the	O
PVE	O
v.6.0	O
Corosync	B-Operating_System
v.3.x	O
is	O
in	O
use	O
(	O
not	O
compatible	O
with	O
the	O
earlier	O
PVE	O
versions	O
)	O
.	O
</s>
<s>
If	O
a	O
Proxmox	O
node	B-Protocol
becomes	O
unavailable	O
or	O
fails	O
,	O
the	O
virtual	O
servers	O
can	O
be	O
automatically	O
moved	O
to	O
another	O
node	B-Protocol
and	O
restarted	O
.	O
</s>
<s>
The	O
database	O
and	O
FUSE-based	O
Proxmox	O
Cluster	B-Architecture
filesystem	B-Application
(	O
pmxcfs	O
)	O
makes	O
it	O
possible	O
to	O
perform	O
the	O
configuration	O
of	O
each	O
cluster	B-Architecture
node	B-Protocol
via	O
the	O
Corosync	B-Operating_System
communication	O
stack	O
with	O
SQlite	B-Language
engine	O
.	O
</s>
<s>
At	O
least	O
since	O
2012	O
,	O
in	O
a	O
HA	O
cluster	B-Architecture
,	O
live	O
virtual	B-Architecture
machines	I-Architecture
can	O
be	O
moved	O
from	O
one	O
physical	O
host	O
to	O
another	O
without	O
downtime	O
.	O
</s>
<s>
Since	O
Proxmox	B-Language
VE	I-Language
1.0	O
,	O
released	O
29.10.2008	O
KVM	B-Application
and	O
OpenVZ	B-Language
live	O
migration	O
is	O
supported	O
(	O
starting	O
from	O
version	O
4.0	O
OpenVZ	B-Language
is	O
replaced	O
by	O
LXC	B-Application
)	O
.	O
</s>
<s>
Related	O
to	O
migration	O
,	O
PVE	O
support	O
next	O
VM/Container	O
migration	O
types	O
:	O
</s>
<s>
Also	O
PVE	O
supports	O
VM/Container	O
migration	O
from	O
local	O
storage	O
's	O
(	O
local	O
to	O
Host/Hypervisor	O
)	O
or	O
from	O
(	O
using	O
)	O
a	O
shared	O
storages	O
(	O
e.g.	O
</s>
<s>
NFS/iSCSI/Ceph	O
)	O
.	O
</s>
<s>
Clones	O
are	O
exact	O
copy	O
of	O
the	O
VM/container	O
and	O
a	O
template	O
can	O
be	O
created	O
from	O
VM/Container	O
.	O
</s>
<s>
One	O
can	O
use	O
the	O
template(s )	O
to	O
clone	O
them	O
to	O
the	O
new	O
VM/container	O
.	O
</s>
<s>
Proxmox	B-Language
VE	I-Language
has	O
pre-packaged	O
server	O
software	B-Application
appliances	I-Application
which	O
can	O
be	O
downloaded	O
via	O
the	O
GUI	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
download	O
and	O
deploy	O
appliances	O
from	O
the	O
TurnKey	B-General_Concept
Linux	I-General_Concept
Virtual	I-General_Concept
Appliance	I-General_Concept
Library	I-General_Concept
.	O
</s>
<s>
PVE	O
includes	O
backup	B-Protocol
software	O
,	O
vzdump	O
,	O
which	O
allows	O
data	B-General_Concept
compression	I-General_Concept
and	O
on-line	O
operation	O
(	O
snapshot	B-Application
mode	O
)	O
.	O
</s>
<s>
Since	O
2020	O
there	O
's	O
also	O
an	O
advanced	O
client-server	B-Operating_System
software	O
for	O
that	O
called	O
Proxmox	B-Application
Backup	I-Application
Server	I-Application
(	O
PBS	O
)	O
,	O
which	O
offers	O
deduplication	B-General_Concept
,	O
compression	O
,	O
authenticated	B-Algorithm
encryption	I-Algorithm
and	O
incremental	B-General_Concept
backups	I-General_Concept
.	O
</s>
<s>
Backup	B-Protocol
can	O
be	O
made	O
only	O
on	O
storages	O
selected	O
as	O
a	O
backup	B-Protocol
(	O
type	O
)	O
of	O
the	O
storage	O
,	O
and	O
they	O
may	O
be	O
on	O
:	O
</s>
<s>
There	O
are	O
a	O
few	O
levels	O
of	O
backup	B-Protocol
:	O
</s>
<s>
There	O
are	O
also	O
a	O
few	O
backup	B-Protocol
modes	O
:	O
</s>
<s>
Stop	O
mode	O
-	O
provides	O
highest	O
consistency	O
,	O
it	O
includes	O
stopping	O
VM/container	O
,	O
creating	O
backup	B-Protocol
and	O
when	O
finished	O
,	O
starting	O
it	O
again	O
.	O
</s>
<s>
Suspend	O
mode	O
-	O
provides	O
a	O
little	O
bit	O
lower	O
consistency	O
,	O
it	O
includes	O
suspending	O
VM/container	O
,	O
then	O
starting	O
snapshot	B-Application
mode	O
and	O
creating	O
backup	B-Protocol
and	O
when	O
finished	O
,	O
starting	O
it	O
again	O
(	O
from	O
suspend	O
)	O
.	O
</s>
<s>
Snapshot	B-Application
mode	O
-	O
provides	O
lowest	O
operation	O
downtime	O
,	O
it	O
includes	O
snapshoting	O
the	O
VM/container	O
,	O
creating	O
backup	B-Protocol
(	O
live	O
)	O
without	O
stopping	O
the	O
VM/container	O
(	O
usage	O
of	O
the	O
guest	O
agent	O
is	O
advised	O
in	O
this	O
mode	O
)	O
.	O
</s>
<s>
PVE	O
also	O
support	O
creating	O
the	O
snapshot	B-Application
of	O
the	O
VM/container	O
in	O
time	O
.	O
</s>
<s>
You	O
can	O
create	O
many	O
snapshots	B-Application
(	O
for	O
example	O
before	O
updating	O
the	O
VM/container	O
)	O
and	O
switch	O
back	O
to	O
any	O
one	O
of	O
them	O
.	O
</s>
<s>
PVE	O
includes	O
integrated	O
firewall	B-Application
in	O
three	O
levels	O
:	O
</s>
<s>
Cluster	B-Architecture
wide	O
.	O
</s>
<s>
Per	O
PVE	O
node	B-Protocol
(	O
host/hypervisor	O
)	O
.	O
</s>
<s>
Per	O
VM/Linux	O
container	B-Application
(	O
guests	O
)	O
.	O
</s>
<s>
In	O
Proxmox	B-Language
VE	I-Language
7.2	O
(	O
May	O
2022	O
)	O
there	O
are	O
known	O
limitations	O
:	O
</s>
<s>
Number	O
of	O
hosts	O
(	O
physical	O
servers	O
)	O
in	O
high	O
availability	O
cluster	B-Architecture
:	O
32+	O
(	O
official	O
,	O
but	O
more	O
is	O
possible	O
)	O
.	O
</s>
<s>
Maximum	O
number	O
of	O
logical	O
networks	O
when	O
using	O
VLANs	B-General_Concept
:	O
4094	O
.	O
</s>
<s>
Maximum	O
number	O
of	O
logical	O
networks	O
when	O
using	O
VxLANs	B-Protocol
(	O
with	O
SDN	O
)	O
:	O
16	O
777	O
216	O
.	O
</s>
<s>
Maximum	O
number	O
of	O
logical	O
networks	O
when	O
using	O
QinQ	O
(	O
so	O
called	O
Stacked	O
VLAN	B-General_Concept
)	O
:	O
16	O
777	O
216	O
.	O
</s>
