{{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].}}

== Kernel installation Requirements ==<!--T:5-->

{{Note|In case <!--T:6-->This guide assumes you want are running '''RHEL (CentOS, Scientific Linux) 6''' on your system. Currently, this is a recommended platform to recompile the kernel yourself rather than use the one provided by run OpenVZ, see [[kernel build]]on.}}

Get the kernel binary RPM from the [http://openvz.org/download/kernel=== / Download » Kernel] page, or directly from [httpvz file system === <!--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.7-->

Next, install the kernel RPM you chose<!--T:8-->It is recommended to use a separate partition for containers (by default '''/vz''') and format it to '''ext4'''.

=== yum pre-setup === <!--T:9--> <!--T:10-->Download [https://download.openvz.org/openvz.repo openvz.repo] file and put it to your <code>/etc/yum.repos.d/</code> repository: <!--T:11--><pre><nowiki>wget -P /etc/yum.repos.d/ https://download.openvz.org/openvz.repo</nowiki></pre> <!--T:12-->Import OpenVZ GPG key used for signing RPM packages: <!--T:13--><pre><nowiki>rpm -ihv ovzkernel-name*import http://download.rpmopenvz.org/RPM-GPG-Key-OpenVZ</nowiki></pre>

{{Note|<tt>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 -U</tt> (where <tt>-U</tt> stands for ''upgrade'') should '''not''' be used, otherwise all currently installed kernels will be uninstalledkey database as described on the [[Package signatures]] page.}}

== Configuring the bootloader Kernel installation ==<!--T:14-->

In case GRUB <!--T:15-->Limited OpenVZ functionality is used as the boot loadersupported when you run a recent 3.x kernel (check [[vzctl for upstream kernel]], it will be configured automatically: lines similar to these will be added to the <tt>/boot/grub/grubso OpenVZ kernel installation is optional but still recommended.conf</tt> file:

<pre>title Fedora Core (2.6.8!-022stab029.1) root (hd0,0) kernel /vmlinuz-2.6.8T:16-022stab029.1 ro root=/dev/sda5 quiet rhgb vga=0x31B initrd /initrd-2.6.8-022stab029.1.img</pre>Change <tt>Fedora Core</tt> to <tt>OpenVZ</tt> (just for clarity reasons, so the OpenVZ kernels will not be mixed up with non OpenVZ ones). 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:# yum install vzkernel

== System configuration == <pre>title OpenVZ (2.6.8!-022stab029.1) root (hd0,0) kernel /vmlinuz-2.6.8T:17-022stab029.1 ro root=/dev/sda5 initrd /initrd-2.6.8-022stab029.1.img</pre>

=== 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 === SELinux should be disabled. To that effect, put the following line to <code>/etc/sysconfig/selinux</code>!--T:<pre>SELINUX=disabled</pre> === Conntracks === In the stable OpenVZ kernels (those that are 2.6.826--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]]. To enable conntracks for VE0, add the following line to <code>/etc/modules.conf</code> file:<pre>options ip_conntrack ip_conntrack_enable_ve0=1</pre>

{{Note|in kernels later than 2<!--T:27-->SELinux should be disabled.6.8, connection tracking is enabled by default}}Put <code>SELINUX=disabled</code> to <code>/etc/sysconfig/selinux</code>:

<!--T:28-->echo "SELINUX== Rebooting into OpenVZ kernel ==disabled" > /etc/sysconfig/selinux

Now reboot the machine and choose "OpenVZ" on the boot loader menu. If the OpenVZ kernel has been booted successfully, proceed to installing the user== Tools installation == <!-level tools for OpenVZ.-T:29-->

== Installing <!--T:30-->{{Out|Before installing tools, please read about [[vzstats]] and opt-out if you don't want to help the utilities ==project.}}

<!--T:31-->OpenVZ needs some user-level tools installed. Those are:

; vzctl <!--T: A utility to control OpenVZ VPSs (create, destroy, start, stop, set parameters etc.)32-->; # yum install vzctl vzquota: A utility to manage quotas for VPSs. Mostly used indirectly (by vzctl).ploop

Download the binary RPMs of these utilities from [http://openvz.org/download/utils/ Download » Utils], or directly from [http://download.openvz.org/utils/ download.openvz.org/utils], or from one of its [[Download mirrors|mirrors]]. Install them== Reboot into OpenVZ == <!--T:33-->

<pre>rpm !--T:34--Uhv vzctl*.rpm vzquota*.rpm</pre> If rpm complains about unresolved dependencies, you'll have to satisfy them first, then repeat Now reboot the installation. When all machine and choose "OpenVZ" on the tools are installed, start the OpenVZ subsystemboot loader menu (it should be default choice). == Starting OpenVZ == As root, execute the following command: <pre>/sbin/service vz start</pre>

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.