Introduction

Virtuozzo (formerly OpenVZ) is a powerful operating system-level virtualization technology that allows a single physical server to run multiple isolated Linux environments known as containers or Virtual Private Servers (VPS). These containers behave like independent servers but share the same Linux kernel, making them lightweight, fast, and resource-efficient.

Prerequisites

Before working with Virtuozzo/OpenVZ commands, ensure the following requirements are met:

A Linux-based server with Virtuozzo/OpenVZ installed

Root or sudo access to the host node

Basic knowledge of Linux command-line operations

Installed OpenVZ/Virtuozzo utilities such as:

  • vzctl (for container management)
  • vzlist (for listing containers)

IMPLEMENTATION

 
Open VZ Commands
Introduction

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vz -> recommends ext3 file system
PIM -> IP:4643
PMC -> mangaing h/w node
PPP -> for managing a single container
All the above things need a license from parallel
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Templates

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OS template -> vzpkg (cache needs to created before creating the container)
EZ template -> points to the repository that contains packages that constitute the template
Application template -> mysql template
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To create a container

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vzctl create
the container ID > 100
32 -bit integer
ID – 0 -> h/w node
ID -1 -> service container

/etc/vz/conf -> for the sample file names (only use the main part of the file name)

vzctl set – configure the container
vzctl exec – run anything on the container
vzctl status/vzlist 101

vzpkg – for adding application templates on h/w node (/vz/templates)
– the same command can be used for installing/removing the template into a the container.

Virtuozzo – User’s guide

OS virtualization – (1-2% of is spent on the virtualization s/w)
VZFS – allows sharing of common files among containers
Hardware node & Containers

/etc/vz/vz.conf
/etc/vz/conf/
/etc/vzbackup.conf

Standard migration
vzmigrate

Zero downtime migration
vzmigrate –online –require-realtime my_node.com 101

Move the container within the h/w node
vzmlocal

Backup & restore
vzabackup/vzarestore

Reinstall container
vzctl recover -> restores the VZFS symlinks
vzctl reinstall -> creates new private area for the container, copies the old private area to /old dir
– vps.configure, vps.reinstall

Delete the container
vzctl destroy

Disabling the container
vzctl set

Suspending the container
vzctl suspend

Setting up resources
disk quotas – first level(how much files or disk space the container can use) and second level (quotaugidlimit > no of entries in /etc/passwd or group files)
Container must be restarted to come this changes into effect

vzquota – to check the status of the quota info

Cleaning up containers – to move identical files from contrainers to /vz/template/vc folder
vzcache

Linking container files with application templates
vzpkg link
vzpkglink
vzpkgls

Managing CPU – cpu share and the number of processors the node can make use of.
vzcpucheck

Network traffic
/etc/vz/conf/networks_classes – after any changes, you need to service vz accrestart
class 0 – no accounting will be performed
class 1 – defined by containers to match any IP address
vznetstat

Bandwidth management (outgoing traffic)
service vz shaperon, shaperrestart, shaperoff
BANDWIDTH -> kilobites per second
TOTALRATE -> ::

For container
RATE -> ::
RATEBOUND -> to specify if the bandwidth is limited to the RATEBOUND
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Monitoring tools

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vzstat
vzps
vzpid
vztop
vzsetxinetd

Virtuozzo networks
vznetcfg if list

vznetcfg vlan add eth0 5
vznetcfg vlan del eth0.5

vznetcfg net addif vznetwork1 eth0
vznetcfg net delif eth0

vznetcfg net new vznetwork1
vznetcfg net del vznetwork1
vznetcfg net list

venet0 –?

License
vzlicload
vzlicupdate
vzlicview

Keeping system up2date
The h/w node can be updated using the normal update procedures without affecting virtuozzo
vzup2date – /etc/sysconfig/vzup2date/vzup2date.conf
vzup2date -m batch install –core
vzup2date -t -m batch install –all-os

Updating the containers
vzpkg update 101 redhat-el5-x86
vzpkg update 101
vzpkg update cache fedora-core-8-x86

Loading iptables modules
/etc/sysconfig/iptables-config
/etc/vz/vz.conf
/etc/vz/conf/.conf

VZFS-v2

Virtuozzo – Templates management guide

/vz/template
/vz/private/
/vz/root/

vzpkg – for managing VZ template
vzpkgls – for listing standard template

vzpkg install -p 110 yum

Virtuozzo – Managing UBC Resources

vzcfgvalidate

VE0CPUUNITS
SLM parameters

i-node setups

ext3 – 1 inode per every 4K

CONCLUSION

Virtuozzo/OpenVZ commands provide a simple yet powerful way to manage multiple virtual environments on a single physical server. With tools like vzctl, administrators can easily control the full lifecycle of containers—from creation and configuration to monitoring and shutdown.

By mastering these commands, system administrators can efficiently handle VPS hosting environments, improve server utilization, and maintain high performance with minimal overhead. Even though modern technologies like KVM and Docker are widely used today, OpenVZ/Virtuozzo remains relevant in many legacy hosting infrastructures.

 
 
 
 

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