factor out cleanup method

[pve-docs.git] / pve-faq.adoc

Frequently Asked Questions
==========================
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NOTE: New FAQs are appended to the bottom of this section.

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[qanda]

What distribution is {pve} based on?::

{pve} is based on http://www.debian.org[Debian GNU/Linux]

What license does the {pve} project use?::

{pve} code is licensed under the GNU Affero General Public License,
version 3.

Will {pve} run on a 32bit processor?::

{pve} works only on 64-bit CPUs (AMD or Intel). There is no plan
for 32-bit for the platform.
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NOTE: VMs and Containers can be both 32-bit and/or 64-bit.

Does my CPU support virtualization?::

To check if your CPU is virtualization compatible, check for the `vmx`
or `svm` tag in this command output:
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----
egrep '(vmx|svm)' /proc/cpuinfo
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Supported Intel CPUs::

64-bit processors with
http://en.wikipedia.org/wiki/Virtualization_Technology#Intel_virtualization_.28VT-x.29[Intel
Virtualization Technology (Intel VT-x)] support. (http://ark.intel.com/search/advanced/?s=t&VTX=true&InstructionSet=64-bit[List of processors with Intel VT and 64-bit])

Supported AMD CPUs::

64-bit processors with
http://en.wikipedia.org/wiki/Virtualization_Technology#AMD_virtualization_.28AMD-V.29[AMD
Virtualization Technology (AMD-V)] support.

What is a container, CT, VE, Virtual Private Server, VPS?::

Operating-system-level virtualization is a server-virtualization
method where the kernel of an operating system allows for multiple
isolated user-space instances, instead of just one. We call such
instances containers. As containers use the host's kernel they are
limited to Linux guests.

What is a QEMU/KVM guest (or VM)?::

A QEMU/KVM guest (or VM) is a guest system running virtualized under
{pve} using QEMU and the Linux KVM kernel module.

What is QEMU?::

QEMU is a generic and open source machine emulator and
virtualizer. QEMU uses the Linux KVM kernel module to achieve near
native performance by executing the guest code directly on the host
CPU.
It is not limited to Linux guests but allows arbitrary operating systems
to run.

How long will my {pve} version be supported?::

{pve} versions are supported at least as long as the corresponding
Debian Version is
https://wiki.debian.org/DebianOldStable[oldstable]. {pve} uses a
rolling release model and using the latest stable version is always
recommended.
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[width="100%",cols="5*d",options="header"]
|===========================================================
| {pve} Version | Debian Version    | First Release | Debian EOL | Proxmox EOL
| {pve} 4.x     | Debian 8 (Jessie) | 2015-10       | 2018-05    | tba
| {pve} 3.x     | Debian 7 (Wheezy) | 2013-05       | 2016-04    | 2017-02
| {pve} 2.x     | Debian 6 (Squeeze)| 2012-04       | 2014-05    | 2014-05
| {pve} 1.x     | Debian 5 (Lenny)  | 2008-10       | 2012-03    | 2013-01
|===========================================================

LXC vs LXD vs Proxmox Containers vs Docker::

LXC is a userspace interface for the Linux kernel containment
features. Through a powerful API and simple tools, it lets Linux users
easily create and manage system containers. LXC, as well as the former
OpenVZ, aims at *system virtualization*, i.e. allows you to run a
complete OS inside a container, where you log in as ssh, add users,
run apache, etc...
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LXD is building on top of LXC to provide a new, better user
experience. Under the hood, LXD uses LXC through `liblxc` and its Go
binding to create and manage the containers. It's basically an
alternative to LXC's tools and distribution template system with the
added features that come from being controllable over the network.
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Proxmox Containers also aims at *system virtualization*, and thus uses
LXC as the basis of its own container offer. The Proxmox Container
Toolkit is called `pct`, and is tightly coupled with {pve}. That means
that it is aware of the cluster setup, and it can use the same network
and storage resources as fully virtualized VMs. You can even use the
{pve} firewall, create and restore backups, or manage containers using
the HA framework. Everything can be controlled over the network using
the {pve} API.
+
Docker aims at running a *single* application running in a contained
environment. Hence you're managing a docker instance from the host with the
docker toolkit. It is not recommended to run docker directly on your
{pve} host.
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NOTE: You can however perfectly install and use docker inside a Proxmox Qemu
VM, and thus getting the benefit of software containerization with the very
strong isolation that VMs provide.