{{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].}}

There are also additional requirements, that affect various aspects of using disk quotas== Requirements == <!--T:<br>1) It's recomended to use separate partion for storing of VEs (by default /vz directory is used for VEs). The reason, why you should do so is that if you wish to use OpenVZ disk quotas, you won't be able to use usual Linux disk quotas on the same partion.<br5-->2) OpenVZ disk quotas currently support only ext2/ext3 filesystems. So use these filesystem types or don't use OpenVZ disk quotas.

In case you have yum utility available on your === /vz file system, you may want to use it effectively to install and update 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 below.=== <!--T:7-->

=== yum pre<!-setup ===-T:8-->If you want It is recommended to use yum, you should set up OpenVZ yum repository firsta separate partition for containers (by default '''/vz''') and format it to '''ext4'''.

Download [http://download.openvz.org/openvz.repo openvz.repo] file and put it to your <code>/etc/=== yum.repos.d/pre-setup === </code> repository. This can be achieved by the following commands, as root!--T:<pre># cd /etc/yum.repos.d# wget http://download.openvz.org/openvz.repo</pre9-->

In case you can not cd <!--T:10-->Download [https://download.openvz.org/openvz.repo openvz.repo] file and put it to your <code>/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./</code> repository:

{{Note|In case you want to recompile the kernel yourself rather than use the one provided by <!--T:12-->Import OpenVZ, see [[kernel build]].}}GPG key used for signing RPM packages:

First, you need to choose what “flavor” of the kernel you want to install<!--T:13--><pre><nowiki>rpm --import http://download. Please refer to [[Kernel flavors]] for more informationopenvz.org/RPM-GPG-Key-OpenVZ</nowiki></pre>

=== Using yum ===Run 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 following command<pre># yum install ovzkernel[-flavor[Package signatures]]</pre>page.

Here == Kernel installation == <code>[!--flavor]</code> is optional, and can be <code>T:14-smp</code> or <code>-enterprise</code>. Refer to [[kernel flavors]] for more info.

=== Using rpm ===<!--T:15-->Get the Limited OpenVZ functionality is supported when you run a recent 3.x kernel binary RPM from the (check [[http://openvz.org/download/vzctl for upstream kernel/ Download » Kernel] page, or directly from [http://download.openvz.org/kernel/ download.openvz.org/kernel], or from one of its [[Download mirrors|mirrors]]. You need only one so OpenVZ kernel RPM so please [[Kernel flavors|choose the appropriate one]] depending on your hardwareinstallation is optional but still recommended.

Next, <!--T:16--># yum install the kernel RPM you chose:vzkernel

== System configuration == <pre># rpm !--T:17-ihv ovzkernel[-flavor]*.rpm</pre>

Here <code>[!--flavor]</code> is optional, and can be <code>T:18-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 uninstalledWith vzctl 4.}} == Configuring the bootloader == In case GRUB 4 or newer there is used as the boot loader, it will be configured automatically: lines similar no need to these will be added to the <tt>/boot/grub/grubdo manual configuration.conf</tt> file: <pre>title Fedora Core (2.6.8-022stab029.1) root (hd0,0) kernel /vmlinuz-2.6.8-022stab029.1 ro root=/dev/sda5 quiet rhgb vga=0x31B initrd /initrd-2.6.8-022stab029.1.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/modprobe.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.