{{Warning|This document briefly article describes the steps needed to install legacy version of OpenVZ on your machine.For current version, see [[Quick installation]].}}

<!--T:1-->This document is also available in briefly describes the following languages: [http://forum.openvz.org/index.php?t=tree&amp;goto=35&amp;#msg_35 French]steps needed to install '''legacy''' OpenVZ on your '''RHEL 6''' (CentOS 6, [http://forum.openvz.org/index.php?t=tree&amp;goto=1805&amp;#msg_1805 German]Scientific Linux 6) machine.

OpenVZ consists of a kernel, user<!--T:2--level tools>For '''Debian''' based systems, and VE templates. This guide tells how to install the kernel and the toolsplease see [[Installation on Debian]].

== Requirements ==<!--T:3-->This guide assumes you are running recent release {{Out|A commercial version of Fedora Core (like FC5) or RHEL/CentOS 4. CurrentlyOpenVZ is available, OpenVZ kernel tries to support the same hardware that Red Hat kernels supportwhich simplifies installation with a single disk as well as supports networked installation using PXE boot. For full hardware compatibility listTo learn more about Virtuozzo and request a free trial, please see [httphttps://www.virtuozzo.com/enopenvz/products/virtuozzo/hcl/ Virtuozzo HCL].}}

=== rpm or yum? =Requirements ==<!--T:5-->

In case <!--T:6-->This guide assumes you have yum utility available are running '''RHEL (CentOS, Scientific Linux) 6''' on you your system. Currently, you may want this is a recommended platform to use it effectively to install and update run OpenVZ packages. In case you don't have yum, or don't want to use it, you can use plain old rpm. Instructions for both rpm and yum are provided belowon.

=== yum pre-setup /vz file system ===If you want to use yum, you should set up OpenVZ yum repository first.<!--T:7-->

Download [http<!--T:8-->It is recommended to use a separate partition for containers (by default '''//download.openvz.org/openvz.repo openvz.repo] file vz''') and put format it to your <code>/etc/yum'''ext4'''.repos.d/</code> repository. This can be achieved by the following commands, as root:<pre># cd /etc/yum.repos.d# wget http://download.openvz.org/openvz.repo</pre>

In case you can not cd to /etc/=== yum.repos.d, it means either yum is not installed on your system, or yum version is too old. In that case, just stick to rpm installation method.pre-setup === <!--T:9-->

{{Note|In case you want to recompile the kernel yourself rather than use the one provided by OpenVZ, see [[kernel build]]<!--T:11--><pre><nowiki>wget -P /etc/yum.}}repos.d/ https://download.openvz.org/openvz.repo</nowiki></pre>

First, you need to choose what “flavor” of the kernel you want to install. Please refer to [[Kernel flavors]] <!--T:12-->Import OpenVZ GPG key used for more information.signing RPM packages:

=== Using yum ===Run the following command<!--T:13--><pre># yum install ovzkernel[<nowiki>rpm --import http://download.openvz.org/RPM-GPG-Key-flavor]OpenVZ</nowiki></pre>

Here <code>[-flavor]</code> is optional, and can be <code>-smp</code> or <code>-enterprise</code>. Refer to To make sure that you are downloading tamper free versions of the signed packages you should verify the fingerprint of the key you imported into the rpm key database as described on the [[kernel flavorsPackage signatures]] for more infopage.

=== Using rpm =Kernel installation ==Get the kernel binary RPM from the [http://openvz.org/download/kernel/ Download » Kernel] page, or directly from [http<!--T://download.openvz.org/kernel/ download.openvz.org/kernel], or from one of its [[Download mirrors|mirrors]]. You need only one kernel RPM so please [[Kernel flavors|choose the appropriate one]] depending on your hardware.14-->

Next<!--T:15-->Limited OpenVZ functionality is supported when you run a recent 3.x kernel (check [[vzctl for upstream kernel]], install the so OpenVZ kernel RPM you chose:installation is optional but still recommended.

<pre!--T:16--># rpm -ihv ovzkernel[-flavor]*.rpm</pre>yum install vzkernel

Here == System configuration == <code>[!--flavor]</code> is optional, and can be <code>T:17-smp</code> or <code>-enterprise</code>. Refer to [[kernel flavors]] for more info.

{{Note|<tt>rpm !-U</tt> (where <tt>-U</tt> stands for ''upgrade'') should '''not''' be used, otherwise all currently installed kernels will be uninstalled.}} == Configuring the bootloader == In case GRUB is used as the boot loader, it will be configured automatically: lines similar to these will be added to the <tt>/boot/grub/grub.conf</tt> fileT: <pre>title Fedora Core (2.6.818-022stab029.1) root (hd0,0) kernel /vmlinuz-2.6.8-022stab029.1 ro root=/dev/sda5 quiet rhgb vga=0x31B> initrd /initrd-2{{Note|With vzctl 4.6.8-022stab029.14 or newer there is no need to do manual configuration.img</pre>Change <tt>Fedora Core</tt> Skip to <tt>OpenVZ</tt> (just for clarity reasons, so the OpenVZ kernels will not be mixed up with non OpenVZ ones)[[#Tools_installation]]. Remove extra arguments from the kernel line, leaving only the <tt>root=...</tt> parameter. The modifed portion of <tt>/etc/grub.conf</tt> should look like this: <pre>title OpenVZ (2.6.8-022stab029.1) root (hd0,0) kernel /vmlinuz-2.6.8-022stab029.1 ro root=/dev/sda5 initrd /initrd-2.6.8-022stab029.1.img</pre> == Configuring ==}}

=== sysctl ===<!--T:20-->

<!--T:21-->There is are a number of kernel parameters that should be set for OpenVZ to work correctly. These parameters are stored in <tt>/etc/sysctl.conf</tt> file. Here is are the relevant part portions of the file; please edit it accordingly.

# TCP Explict Congestion Notification#net.ipv4.tcp_ecn = 0<!--T:25--># we We do not want all our interfaces to send redirects

=== SELinux ===<!--T:26-->

<!--T:27-->SELinux should be disabled. To that effect, put the following line Put <code>SELINUX=disabled</code> to <code>/etc/sysconfig/selinux</code>:<pre>SELINUX=disabled</pre>

<!--T:28-->echo "SELINUX=== Conntracks ===disabled" > /etc/sysconfig/selinux

In the stable OpenVZ kernels (those that are 2.6.8== Tools installation == <!-based) netfilter connection tracking for [[VE0]] is disabled by default. If you have a stateful firewall enabled on the host node (it is there by default) you should either disable it, or enable connection tracking for [[VE0]].-T:29-->

To enable conntracks for VE0, add the following line to <code>/etc/modules.conf</code> file!--T:<pre30-->options ip_conntrack ip_conntrack_enable_ve0=1</pre> {{NoteOut|in kernels later than 2.6.8, connection tracking is enabled by default}} == Rebooting into OpenVZ kernel == Now reboot the machine and choose "OpenVZ" on the boot loader menu. If the OpenVZ kernel has been booted successfully, proceed to Before installing the user-level tools for OpenVZ. == Installing the utilities == OpenVZ needs some user-level tools installed. Those are: ; vzctl: A utility to control OpenVZ VPSs (create, destroy, start, stop, set parameters etc.); vzquota: A utility to manage quotas for VPSs. Mostly used indirectly (by vzctl).  === Using yum === <pre># yum install vzctl vzquota</pre> === Using rpm === Download the binary RPMs of these utilities from please read about [http://openvz.org/download/utils/ Download » Utils], or directly from [http://download.openvz.org/utils/ download.openvz.org/utilsvzstats], or from one of its [[Download mirrors|mirrors]]. Install them: <pre># rpm and opt-Uhv vzctl*out if you don't want to help the project.rpm vzquota*.rpm</pre>}}

== Starting Reboot into OpenVZ ==<!--T:33-->

As root, execute the following command<!--T: <pre34--># /sbin/service vz start</pre>Now reboot the machine and choose "OpenVZ" on the boot loader menu (it should be default choice).

This will load all the needed OpenVZ kernel modules. This script should also start all the VPSs marked to be auto== Download OS templates == <!-started on machine boot (there aren't any yet).-T:35-->

During the next reboot<!--T:36-->An OS template is a Linux distribution installed into a containerand then packed into a gzipped tarball. Using such a cache, this script should a new containercan be executed automaticallycreated in a minute.

The next step <!--T:39-->OpenVZ is to prepare the [[OS template]]: please continue now set up on your machine. Follow on to [[OS template cache preparationbasic operations in OpenVZ environment]] document.