Contents

Introduction
About OpenVZ
Alternates to OpenVZ
Installing OpenVZ
1. 8.04 Hardy
2. 10.04 LTS (Lucid)
OpenVZ Guests
Administration
1. Creating a container from OS template
2. Configuring a container
See also

Introduction

This page describes the installation of OpenVZ on "Ubuntu Server" as a host. In the Hardy release of Ubuntu, the OpenVZ packages are in the "universe" component, which does not have guarantees of support. Note that KVM is the main virtualization technology supported in Ubuntu.

To properly implement the practical steps found in this guide, the reader should be a user of Ubuntu who is comfortable with the use of command-line applications, using the Bourne Again SHell (bash) environment, and editing system configuration files with their preferred text editor application.

About OpenVZ

OpenVZ is a server virtualization solution for Linux. It enables one to create multiple virtual Linux servers which are isolated from the host and from each other, based on a technique called "Operating System Virtualization". Similar techniques are used in Solaris Zones, Linux-VServer and FreeBSD jails. This technique does not use hardware virtualization like KVM, XEN or VMware. The so called "Virtual Servers" or VPSs behave like stand alone servers. They consume less resources than their hardware virtualized counterparts, but must use the same kernel as the host. Therefor you can only have Linux VPSs on a Linux host.

The original documentation can be found here: http://openvz.org/

Alternates to OpenVZ

LXC and Xen are alternatives to OpenVZ.

Installing OpenVZ

* OpenVZ is supported on Ubuntu only for the 8.04 version.

If you are looking for a host node more recent then Ubuntu 8.04 try Proxmox (Proxmox is Debian), Debian, or Centos. In general, OpenVZ support is better on .rpm systems first, Debian second.

If you are interested in seeing OpenVZ on .deb systems, please consider working with the OpenVZ project as the OpenVZ kernel patch is not maintained by the Ubuntu developers.

8.04 Hardy

Install the kernel and tools

$ sudo apt-get install linux-openvz vzctl

Important! Please, make sure that you are using at least the linux-image-2.6.24-19-openvz kernel which is the first really stable kernel without basic usability issues.
Reboot into the openvz kernel
Remove the -server kernel or the -generic if you are on a desktop machine

$ sudo apt-get remove --purge --auto-remove linux-image-.*server

Change the sysctl variables in /etc/sysctl.conf

  # On Hardware Node we generally need
  # packet forwarding enabled and proxy arp disabled
  
  net.ipv4.conf.default.forwarding=1
  net.ipv4.conf.default.proxy_arp=1
  net.ipv4.ip_forward=1
  
  # Enables source route verification
  net.ipv4.conf.all.rp_filter = 1
  
  # Enables the magic-sysrq key
  kernel.sysrq = 1
  
  # TCP Explict Congestion Notification
  #net.ipv4.tcp_ecn = 0
  
  # we do not want all our interfaces to send redirects
  net.ipv4.conf.default.send_redirects = 1
  net.ipv4.conf.all.send_redirects = 0

Apply the sysctl changes

$ sudo sysctl -p

Create a symlink to /vz because most of the vz tools expects the OpenVZ folders to reside there. This step is not necessary, but can eliminate further problems when other vz related components are installed.

$ sudo ln -s /var/lib/vz /vz

10.04 LTS (Lucid)

The information below is old. Follow Install kernel from RPM on Ubuntu 10.04.

Before you begin, please remeber that:

OpenVZ was only supported in Ubuntu 8.04 LTS (Hardy Heron), and not in Ubuntu 10.04 (Lucid Lynx)
At writing moment (november 2010) OpenVZ patch for kernel Linux 2.6.32 works, but is not yet released as stable, and for this reason is not recommended for production environments.
Ext4 filesystem is not yet supported by vzquota, then if you want to have host kernel stability, better use Ext3 for containers space in /vz or /var/lib/vz

Be sure that the system is up-to-date (also kernel)

sudo apt-get update
sudo apt-get upgrade
sudo apt-get upgrade
# Reboot if kernel update

We need now Bash as default Shell. In the next screen, select NO to install dash.

sudo dpkg-reconfigure dash

Install Required Packages For Kernel Compilation

sudo apt-get install kernel-package libncurses5-dev fakeroot wget bzip2 module-assistant debhelper build-essential

Select OpenVZ compile configuration (only one of them):

# For 32bit platform, limited to 3GiB of RAM
Variant="linux-image-generic"
VersionAppendix="-openvz"
MyConfigFile="kernel-2.6.32-i686.config.ovz"

# For 32bit platform, PAE for big memory
Variant="linux-image-generic-pae"
VersionAppendix="-openvz-pae"
MyConfigFile="kernel-2.6.32-i686-PAE.config.ovz"

# For 64bit platform
Variant="linux-image-server"
VersionAppendix="-openvz"
MyConfigFile="kernel-2.6.32-x86_64.config.ovz"

Satisfy the build dependencies for the source package

Package="$(apt-cache showpkg $Variant | grep "^2\.6\.32" | grep "linux-image")"
Package=$(ReturnWord () { echo $3; }; ReturnWord $Package)
sudo apt-get build-dep --no-install-recommends $Package

Prepare linux headers

sudo m-a prepare

Create configuration for kernel compiler

sudo kernel-packageconfig

Optimize compiler multi-core usage (only one time)

Cores=$(Nr () { echo $#; }; Nr $(grep "processor" /proc/cpuinfo | cut -f2 -d":"))
echo "CONCURRENCY_LEVEL := $(($Cores + 1))" | sudo tee -a /etc/kernel-pkg.conf

Get Ubuntu Linux kernel source code for 2.6.32

cd /usr/src
sudo wget http://archive.ubuntu.com/ubuntu/pool/main/l/linux/linux_2.6.32.orig.tar.gz

Get OpenVZ patch for kernel (you can see here if the file has changed)

cd /usr/src
sudo wget http://download.openvz.org/kernel/branches/2.6.32/current/patches/patch-feoktistov.1-combined.gz

Now download:

cd /usr/src
sudo wget http://download.openvz.org/kernel/branches/2.6.32/current/configs/$MyConfigFile

Unpack the Kernel-Source

cd /usr/src
sudo rm -fR linux-2.6.32
sudo tar -xpf linux_2.6.32.orig.tar.gz
sudo rm -fR "linux-2.6.32$VersionAppendix"
sudo mv linux-2.6.32 "linux-2.6.32$VersionAppendix"
sudo rm linux
sudo ln -s "linux-2.6.32$VersionAppendix" linux

Apply OpenVZ patch and configuration

cd /usr/src/linux
sudo gunzip -dc /usr/src/patch-feoktistov.1-combined.gz | sudo patch -p1 --batch
sudo cp -f "/usr/src/$MyConfigFile" .config
sudo make oldconfig

Fix some bugs:

Edit file Documentation/lguest/Makefile and change

all: lguest

clean:

all:

clean:

(or you'll get a next compilation error with eventfd.h and zlib.h)

Now the long kernel compilation and pack:

cd /usr/src/linux
sudo make-kpkg --initrd --append-to-version=$VersionAppendix --revision=1 kernel_image kernel_headers

Install the Kernel

cd /usr/src
ls -l *.deb
sudo dpkg -i linux-image-2.6.32.28-openvz_1_amd64.deb
sudo dpkg -i linux-headers-2.6.32.28-openvz_1_amd64.deb

Create a Initramfs and update Grubs menu.lst or grub.cfg (check the "2.6.32.28-openvz" string according to generated packages)

sudo mkinitramfs -k 2.6.32.28-openvz -o /boot/initrd.img-2.6.32.28-openvz
sudo update-grub

Create a new file, /etc/sysctl.d/10-openvz.conf with the following sysctl variables This step might not be necessary once the vzctl package is going to be updated

### Optimized for Ubuntu 10.04
# vim:ft=sysctl
# sysctl config for OpenVZ
#net.ipv4.ip_forward=1

net.ipv4.conf.default.forwarding = 1
net.ipv4.conf.default.proxy_arp = 1
net.ipv4.ip_forward = 1

# Enables source route verification
net.ipv4.conf.all.rp_filter = 1

# Enables the magic-sysrq key
kernel.sysrq = 1

# TCP Explict Congestion Notification
#net.ipv4.tcp_ecn = 0

# we do not want all our interfaces to send redirects
net.ipv4.conf.default.send_redirects = 0

Apply the sysctl changes

$ sudo sysctl -p /etc/sysctl.d/10-openvz.conf

Install OpenVZ management tools

sudo apt-get install --no-install-recommends vzctl vzquota vzdump

(only when you know the Ext4 support is complete and stable, may want to compile from sources)

Create a Symlink to be FHS-compliant

sudo ln -s /var/lib/vz /vz

If you are using ext4, you almost certainly will encounter a kernel panic when starting a container. Some people mounts filesystem with a 'nodelalloc' option in /etc/fstab , but instead of kernel panic the system can freeze or collapse (See here: http://bugzilla.openvz.org/show_bug.cgi?id=1509)

For the moment, the only alternative to use Ext4 is to set DISK_QUOTA=no in /etc/vz/vz.conf (then space quotas haven't effect to containers)

Reboot into your new OpenVZ-Kernel

sudo reboot

Check your running Kernel

sudo uname -rvo

This Command should give something like this:

2.6.32.28-openvz #1 SMP Tue Sep 24 13:07:07 CEST 2010 GNU/Linux

Ensure that all is fine now.

sudo ps ax | grep -v "grep" | grep "vzmond"

This should give some like:

 3890 ?        S      0:00 [vzmond]

Congratulation. You're now running OpenVZ on Ubuntu 10.04 LTS

If you need FUSE mounts (such as SSHFS) and don't see the fuse module loaded (lsmod | grep fuse), you can enable it with:

sudo modprobe --first-time fuse
echo "fuse" | sudo tee -a /etc/modules

To allow a container to mount fuse devices, you need to give it permissions (container may need to be restarted):

sudo vzctl set 777 --devnodes fuse:rw --save

OpenVZ Guests

Template(s)

Before we can create a new Virtual Private Server, we first have to either download or create a template of the distro we want to use. OpenVZ uses "templates" or "cached templates". The difference is that "templates" are a sort of cookbook for "cached templates" A package manager is then used to download and create the cached template of the chosen distribution. Because most cached versions of popular distro's are already created and not that big, it is easiest to download the cached version and place it in the "/var/lib/vz/template/cache" directory (or the path you have chosen in the "/etc/vz/vz.conf" file).

"Official" cached templates can be found here http://openvz.org/download/template/cache/
"Community" or "contrib" templates can be found here http://ftp.openvz.org/template/precreated/contrib/
BodhiZazen 's - OpenVZ templates - These templates were submitted to the OpenVZ "contrib" set of templates.

Once you have downloaded a template (for example ubuntu-8.04-i386-minimal.tar.gz) and placed it in "/var/lib/vz/template/cache" you can install it using the following command:

sudo vzctl create 777 --ostemplate ubuntu-8.04-i386-minimal

In the example below CT ID of 777 is used; of course any other non-allocated ID could be used.

The section below explains how to create your own cached template. If you installed a default one as explained above, continue to #Administration to learn how to start and enter your new node.

Create Template

For more updated instructions on Ubuntu OpenVZ template creation see: bodhi.zazen's blog, Ubuntu 10.04 OpenVZ Template Creation

- Previous blog entries cover Ubuntu 9.10 -

This section describes how to create an Ubuntu 8.04 Hardy minimal template. This information is somewhat dated and are biased on the Openvz wiki - Debian template creation.

Documentation format:

Run the command on the OpenVZ host system

[HW] $ command

Run the command on the OpenVZ container

[VPS] $ command

Prerequisites

debootstrap

[HW] $ sudo apt-get install debootstrap

Creating template

Running debootstrap

Create a working directory:

[HW] $ mkdir hardy-chroot

Run debootstrap to install a minimal Hardy Heron system into that directory:

[HW] $ sudo debootstrap [--arch ''ARCH''] hardy hardy-chroot

If the ARCH of the host machine is equal to the one of the container, you can skip the --arch option, but if you need to build an OS template for another ARCH, specify it explicitly:
for AMD64/x86_64, use amd64
for i386 i386

Preparing/starting a container

Now you have an installation created by debootstrap, you can run it as a container. In the example below CT ID of 777 is used; of course any other non-allocated ID could be used.

Moving installation to container private area

[HW] $ sudo mv hardy-chroot /vz/private/777

All files needs to be owned by root

[HW] $ sudo chown -R root /vz/private/777

Setting initial container configuration

[HW] $ sudo vzctl set 777 --applyconfig vps.basic --save

Setting container's OSTEMPLATE

[HW] $ echo "OSTEMPLATE=ubuntu-8.04" | sudo tee -a /etc/vz/conf/777.conf >/dev/null

Setting container's IP address. (This is just a temporary setting for the update process to work)

[HW] $ sudo vzctl set 777 --ipadd x.x.x.x --save

Setting DNS server for the container (This is just a temporary setting for the update process to work)

[HW] $ sudo vzctl set 777 --nameserver x.x.x.x --save

Removing udev from the /etc/rcS.d and klogd from the /etc/rc2.d folders
If udev was in place the container might not start, it could be stuck and even vzctl enter would not be able to access the container's command line. If klogd was in place it might not let the runlevel 2 change finish.

[HW] $ sudo rm /vz/private/777/etc/rcS.d/S10udev /vz/private/777/etc/rc2.d/S11klogd

Starting the container

[HW] $ sudo vzctl start 777

Modify the installation

Enter a container:

[HW] $ vzctl enter 777

Warning!!! Do not run the commands below on the hardware node, they are only to be run within the container!
Note: You will not need to use sudo within the container, you enter as root when you use vzctl enter.
Remove unnecessary packages:

[VPS] $ apt-get remove --purge busybox-initramfs console-setup dmidecode eject \
ethtool initramfs-tools klibc-utils laptop-detect libiw29 libklibc \
libvolume-id0 mii-diag module-init-tools ntpdate pciutils pcmciautils ubuntu-minimal \
udev usbutils wireless-tools wpasupplicant xkb-data tasksel tasksel-data

Note: If you want to use the tasksel tool, do not remove it — but then you have to let laptop-detect stay.
Note: On removing the deb-package module-init-tools, a fake-modprobe is needed for IPv6 addresses, see below!
The DHCP client can be also removed if you know that you will not need it.

[VPS] $ apt-get remove --purge --auto-remove dhcp3-client dhcp3-common

Clean up after udev

[VPS] $ rm -fr /lib/udev

Disable getty On a usual Linux system, getty is running on a virtual terminals, which a container does not have. So, having getty running doesn't make sense; more to say, it complains it can not open a terminal device and this clutters the logs.

[VPS] $ initctl stop tty1
[VPS] $ initctl stop tty2
[VPS] $ initctl stop tty3
[VPS] $ initctl stop tty4
[VPS] $ initctl stop tty5
[VPS] $ initctl stop tty6
[VPS] $ rm /etc/event.d/tty*
[VPS] $ rm /etc/init/tty*

Set sane permissions for /root directory

[VPS] $ chmod 700 /root

Disable root login

[VPS] $ usermod -p ‘!’ root

"fake-modprobe" needed for IPv6 addresses

[VPS] $ ln -s /bin/true /sbin/modprobe

On setup IPv6, the command "modprobe -Q IPv6" is called, which fails without the "fake-modprobe"
Set the default repositories for Hardy
Make sure that you replace the <YOURCOUNTRY> with the your country code

[VPS] $ COUNTRY=<YOURCOUNTRY>. cat >/etc/apt/sources.list <<EOF
# Binary
deb http://${COUNTRY}archive.ubuntu.com/ubuntu/ hardy main restricted universe multiverse
deb http://${COUNTRY}archive.ubuntu.com/ubuntu/ hardy-updates main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu hardy-security main restricted universe multiverse

# Binary Canonical
# deb http://archive.canonical.com/ubuntu hardy partner

# Binary backport
# deb http://${COUNTRY}archive.ubuntu.com/ubuntu/ hardy-backports main restricted universe multiverse

# Source
# deb-src http://${COUNTRY}archive.ubuntu.com/ubuntu/ hardy main restricted universe multiverse
# deb-src http://${COUNTRY}archive.ubuntu.com/ubuntu/ hardy-updates main restricted universe multiverse
# deb-src http://security.ubuntu.com/ubuntu hardy-security main restricted universe multiverse

# Source backport
# deb-src http://${COUNTRY}archive.ubuntu.com/ubuntu/ hardy-backports main restricted universe multiverse

# Source Canonical
# deb-src http://archive.canonical.com/ubuntu hardy partner
EOF

Note: Only the "main restricted universe multiverse" binary repositories are enabled. Change it if you need more.
Apply new security updates

[VPS] $ apt-get update && apt-get upgrade

Install some more packages

[VPS] $ apt-get install ssh quota

Fix SSH host keys This is only useful if you installed SSH above. Each individual container should have its own pair of SSH host keys. The code below will wipe out the existing SSH keys and instruct the newly-created container to create new SSH keys on first boot.

[VPS] $ rm -f /etc/ssh/ssh_host_*
[VPS] $ cat << EOF > /etc/rc2.d/S15ssh_gen_host_keys
#!/bin/sh
ssh-keygen -f /etc/ssh/ssh_host_rsa_key -t rsa -N ''
ssh-keygen -f /etc/ssh/ssh_host_dsa_key -t dsa -N ''
rm -f \$0
EOF
[VPS] $ chmod a+x /etc/rc2.d/S15ssh_gen_host_keys

Link /etc/mtab to /proc/mounts, so df and friends will work:

[VPS] $ rm -f /etc/mtab
[VPS] $ ln -s /proc/mounts /etc/mtab

After that, it would make sense to disable mtab.sh script which messes with /etc/mtab

[VPS] $ update-rc.d -f mtab.sh remove

Disable some services In most of the cases you don't want klogd to run -- the only exception is if you configure iptables to log some events -- so you can disable it.

[VPS] $ update-rc.d -f klogd remove

Set default hostname

[VPS] $ echo "localhost" > /etc/hostname

Set /etc/hosts

[VPS] $ echo "127.0.0.1 localhost.localdomain localhost" > /etc/hosts

Add ptys to /dev
This is needed in case /dev/pts will not be mounted after container start. In case /dev/ttyp* and /dev/ptyp* files are present, and LEGACY_PTYS support is enabled in the kernel, vzctl will still be able to enter the container.

[VPS] $ cd /dev && /sbin/MAKEDEV ptyp

Remove nameserver(s)
[VPS] $ > /etc/resolv.conf
Clean aptcahche

[VPS] $ apt-get clean

Cleaning up log files

[VPS] $ > /var/log/messages; > /var/log/auth.log; > /var/log/kern.log; > /var/log/bootstrap.log; \
> /var/log/dpkg.log; > /var/log/syslog; > /var/log/daemon.log; > /var/log/apt/term.log; rm -f /var/log/*.0 /var/log/*.1

Exit the container

[VPS] $ exit

Preparing for and packing template cache

The following commands should be run on the host system (i.e. not inside a container).
We don't need an IP for the container anymore, and we definitely do not need it in template cache, so remove it

[HW] $ sudo vzctl set 777 --ipdel all --save

Stop the container

[HW] $ sudo vzctl stop 777

Change dir to the container private

[HW] $ cd /vz/private/777

Now create a cached OS tarball. In the command below, you'll want to replace <arch> with your architecture (i386, amd64).
Note the space and the dot at the end of the command.

[HW] $ sudo tar -czf /vz/template/cache/ubuntu-8.04-<arch>-minimal.tar.gz .

Cleanup

[HW] $ sudo vzctl destroy 777
[HW] $ sudo rm -f /etc/vz/conf/777.conf.destroyed

Testing template cache

We can now create a container based on the just-created template cache. Be sure to change arch to your architecture just like you did when you named the tarball above.

[HW] $ sudo vzctl create 123456 --ostemplate ubuntu-8.04-<arch>-minimal

Now make sure that your new container works

[HW] $ sudo vzctl start 123456
[HW] $ sudo vzctl exec 123456 ps axf

You should see that a few processes are running.
Cleanup

[HW] $ sudo vzctl stop 123456
[HW] $ sudo vzctl destroy 123456
[HW] $ sudo rm -f /etc/vz/conf/123456.conf.destroyed

9.10 (Karmic) VPS

Create openvz.conf in /etc/init and fix init sequence to have OpenVZ working with upstart. Original reference.

[VPS] # cat << EOF >  /etc/init/openvz.conf
description "Fix OpenVZ"
start on startup

task
pre-start script
mount -t proc proc /proc
mount -t devpts devpts /dev/pts
mount -t sysfs sys /sys
mount -t tmpfs varrun /var/run
mount -t tmpfs varlock /var/lock
mkdir -p /var/run/network
touch /var/run/utmp
chmod 664 /var/run/utmp
chown root.utmp /var/run/utmp
if [ "$(find /etc/network/ -name upstart -type f)" ]; then
chmod -x /etc/network/*/upstart || true
fi
end script

script
start networking
initctl emit filesystem --no-wait
initctl emit local-filesystems --no-wait
initctl emit virtual-filesystems --no-wait
init 2
end script
EOF

Check /bin/sh symlinked to bash?:

# file /bin/sh
/bin/sh: symbolic link to `bash'

Fix the "init: tty1 main process ended, respawning" syslog message

[VPS] # find /etc/init/ -maxdepth 1 -type f -name tty\* -print0 | /usr/bin/xargs -r0 -i -t sed -i 's/respawn/#respawn/g' {}

10.04 LTS (Lucid) VPS

To run a 10.04 VPS (VE in OpenVZ-speech) you need to make serveral adjustments inside the VPS to make it boot. The steps are outlined at http://blog.bodhizazen.net/linux/ubuntu-10-04-openvz-templates/ .

Administration

When we create a VPS, we must give it a number. This number must be unique and it is used to control the VPS during it's existence. A good guideline is to use the last three digits of the ip address you are going to use for this VPS. i.e.: 10.0.0.101 would be VPS 101!

Creating a container from OS template

Create a container

[HW] $ sudo vzctl create <VEID> --ostemplate <the name of your template>

Set the IP, nameserver, hostname and start the container as described below
Enter into the container (equivalent to chroot)

[HW] $ sudo vzctl enter [VEID]

Install the langauge support. language-pack-[LANGUAGE]-base, for english use language-pack-en-base

[VPS] $ apt-get install language-pack-en-base

You might need to run apt-get update first
Set timezone

[VPS] $ dpkg-reconfigure tzdata

Exit the container

[VPS] $ exit

Configuring a container

Adding IP address

[HW] $ sudo vzctl set [VEID|VENAME] --ipadd [IP_ADDRESS] --save

Deleting IP address

[HW] $ sudo vzctl set [VEID|VENAME] --ipdel [IP_ADDRESS] --save

Setting hostname

[HW] $ sudo vzctl set [VEID|VENAME] --hostname [HOSTNAME] --save

Setting nameserver

[HW] $ sudo vzctl set [VEID|VENAME] --nameserver [NAMESERVER_IP] --save

Setting virtual name

[HW] $ sudo vzctl set [VEID] --name [VENAME] --save

Start, stop, take snapshot or revert to snapshot

Start

[HW] $ sudo vzctl start [VEID|VENAME]

Important! As of 2008-06-04 there is a bug in the linux-image-2.6.24-18-openvz and earlier kernels. It prevents the network settings from being copied into the VE, and you cannot use the cp and mv command inside your VE.
Stop

[HW] $ sudo vzctl stop [VEID|VENAME]

Take snapshot

[HW] $ sudo vzctl chkpnt [VEID|VENAME] [--dumpfile <name>]

Revert to snapshot

[HW] $ sudo vzctl restore [VEID|VENAME] [--dumpfile <name>]

Destroying a container

[HW] $ sudo vzctl destroy [VEID|VENAME]

Monitoring

List running VPS

[HW] $ sudo vzlist

List all VPS

[HW] $ sudo vzlist -a

Networking

Networking nodes using NAT or Bridge
- http://ubuntuforums.org/showthread.php?p=3798970#post3798970

Networking, IPv6 with venet0 device

Set the NET_ADMIN:on capability.

[HW] $ sudo vzctl set VPSID --capability net_admin:on

Edit the /etc/vz/dists/scripts/debian-add_ip.sh script. Add the up route --inet6 add ::/0 venet0 line under the venet0 IPv6 configuration.

iface venet0 inet6 static
        address ::1
        netmask 128
        up route --inet6 add ::/0 venet0

Change the proxy_ndp and the ipv6 forwarding state to 1.

[HW] $ sudo echo "1" > /proc/sys/net/ipv6/conf/eth0/proxy_ndp
[HW] $ sudo echo "1" > /proc/sys/net/ipv6/conf/eth0/forwarding
[HW] $ sudo echo "1" > /proc/sys/net/ipv6/conf/venet0/forwarding

Change the sysctl variables in /etc/sysctl.conf

net.ipv6.conf.default.forwarding = 1
net.ipv6.conf.all.forwarding     = 1
net.ipv6.conf.eth0.proxy_ndp     = 1

Add the IPv6 address for the virtual node.

[HW] $ sudo vzctl set VEID --ipadd fc00::01 --save

Restart the virtual node.

[HW] $ sudo vzctl restart VEID

Test Your configuration.

[HW] $ sudo vzctl enter VEID
[VPS] $ ip addr
3: venet0: <BROADCAST,POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
    link/void
    inet 127.0.0.1/32 scope host
    inet 123.45.67.89/32 scope global
    inet6 ::1/128 scope host
    inet6 fc00::1/128 scope global
[VPS] $ ping6 -n www.6bone.net
PING www.6bone.net(2001:5c0:0:2::24) 56 data bytes
64 bytes from 2001:5c0:0:2::24: icmp_seq=1 ttl=52 time=203 ms

Ubuntu Documentation

OpenVZ