{{Warning|This document briefly article describes the steps needed to install legacy version of OpenVZ on your (RPM based) machine. For '''Debian''' based systems current version, see [[Installation on DebianQuick 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], [http://forum.openvz.org/index.php?t=tree&amp;goto=1805&amp;#msg_1805 German],[http://wiki.openvz.jp Japanese]steps needed to install '''legacy''' OpenVZ on your '''RHEL 6''' (CentOS 6,[[Quick_installation_(SpanishScientific Linux 6)|Spanish]]machine.

OpenVZ consists of a kernel, user<!--T:2--level tools>For '''Debian''' based systems, and container 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.swsoftvirtuozzo.com/en/products/virtuozzoopenvz/hcl/ Virtuozzo HCL].}}

==Requirements = Filesystems ===It is recommended to use a separate partition for container's private directories (by default /vz/private/<veid>). The reason why you should do so is that if you wish to use OpenVZ per!--container disk quota, you won't be able to use usual Linux disk quotas on the same partition. Bear in mind, that perT:5-container quota in this context includes not only pure per-container quota, but also usual Linux disk quota used in containers, not on [[HN]].>

At least try to avoid using the root partition for containers<!--T:6-->This guide assumes you are running '''RHEL (CentOS, Scientific Linux) 6''' on your system. Currently, because the root user of this is a container will be able recommended platform to overcome the 5% disk space barrier in some situations. This way the HN root partition can be completely filled and it will break the systemrun OpenVZ on.

OpenVZ per=== /vz file system === <!--T:7-container disk quota is supported only for ext2/ext3 filesystems. So use one of these filesystems (ext3 is recommended) if you need per-container disk quota.>

In case you have === yum utility available on your 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.pre-setup === <!--T:9-->

=== yum pre<!--T:10--setup ===>If you want Download [https://download.openvz.org/openvz.repo openvz.repo] file and put it to use yum, you should set up OpenVZ your <code>/etc/yum .repos.d/</code> repository first.:

Download [http<!--T://download.openvz.org/openvz.repo openvz.repo] file and put it to your <code11-->/etc/yum.repos.d/</codepre> repository. This can be achieved by the following commands, as root:<prenowiki># cd wget -P /etc/yum.repos.d# wget http/ https://download.openvz.org/openvz.repo# rpm --import http://download.openvz.org/RPM-GPG-Key-OpenVZ</prenowiki> 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. == Kernel installation == {{Note|In case you want to recompile the kernel yourself rather than use the one provided by OpenVZ, see [[kernel build]].}} First, you need to choose what “flavor” of the kernel you want to install. Please refer to [[Kernel flavors]] for more information. === Using yum ===Run the following command<pre># yum install ovzkernel[-flavor]</pre> Here <code>[-flavor]</code> is optional, and can be <code>-smp</code> or <code>-enterprise</code>. Refer to [[kernel flavors]] for more info. {{Note|if you need to install <code>x86_64</code> kernel and yum offers to install both <code>x86_64</code> and <code>i686</code> kernels, answer <code>No</code> and specify architecture manually, like this: <code>yum install ovzkernel[-flavor].x86_64</code>. This is fixed in newer yum versions.}}

=== Using rpm ===<!--T:12-->Get the kernel binary Import OpenVZ GPG key used for signing RPM from the [[Download/kernel]] page. You only need one kernel RPM so please [[Kernel flavors|choose the appropriate one]] depending on your hardware.packages:

Next, install the kernel <!--T:13--><pre><nowiki>rpm --import http://download.openvz.org/RPM you chose:-GPG-Key-OpenVZ</nowiki></pre>

<pre># 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 -ihv ovzkernelkey database as described on the [-flavor[Package signatures]*] page.rpm</pre>

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.

{{Note|<tt>rpm !--T:15--U</tt> Limited OpenVZ functionality is supported when you run a recent 3.x kernel (where <tt>-U</tt> stands check [[vzctl for ''upgrade'') should '''not''' be usedupstream kernel]], otherwise all currently installed kernels will be uninstalledso OpenVZ kernel installation is optional but still recommended.}}

In case GRUB is used as the boot loader, it will be configured automatically== System configuration == <!--T: lines similar to these will be added to the <tt17-->/boot/grub/grub.conf</tt> file:

<pre>title Fedora Core (2.6.8!-022stab029.1) root (hd0,0) kernel /vmlinuz-2.6.8T:18-022stab029.1 ro root=/dev/sda5 quiet rhgb vga=0x31B initrd /initrd-2.6.8-022stab029.1.img</pre>Change <tt>Fedora Core</tt> {{Note|With vzctl 4.4 or newer there is no need to <tt>OpenVZ</tt> (just for clarity reasons, so the OpenVZ kernels will not be mixed up with non-OpenVZ ones)do manual configuration. 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-2Skip to [[#Tools_installation]].6.8-022stab029.1.img</pre> == Configuring ==}}

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

<!--T:21-->There 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>:<pre>SELINUX=disabled</pre> === Conntracks === In the stable OpenVZ kernels (those that are 2.6.8!--based) netfilter connection tracking for [[CT0]] 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 [[CT0]]. To enable conntracks for CT0, add the following line to <code>/etc/modprobe.conf</code> fileT:<pre>options ip_conntrack ip_conntrack_enable_ve0=1</pre> {{Note|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 installing the user26-level tools for OpenVZ. If you are installing on x86_64 CentOS or Fedora system, you may want to continue the setup process using the [[Install_OpenVZ_on_a_x86_64_system_Centos-Fedora|x86_64 guide]]. == Installing the utilities ==>

OpenVZ needs some user<!-level tools installed-T:27-->SELinux should be disabled. Those arePut <code>SELINUX=disabled</code> to <code>/etc/sysconfig/selinux</code>:

; vzctl <!--T:28-->: A utility to control OpenVZ containers (create, destroy, start, stop, set parameters echo "SELINUX=disabled" > /etc.); vzquota: A utility to manage quotas for containers. Mostly used indirectly (by vzctl)./sysconfig/selinux

==Tools installation = Using yum === <pre># yum install vzctl vzquota</pre!--T:29-->

Download the binary RPMs of these utilities from [[Download/utils]]. Install them<!--T:31-->OpenVZ needs some user-level tools installed:

<pre!--T:32--># rpm -Uhv yum install vzctl*.rpm vzquota*.rpm</pre>ploop

When all <!--T:34-->Now reboot the tools are installed, start machine and choose "OpenVZ" on 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 containers 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.