Create and starting a openvz container.
To create and start a container, run the following commands:
# vzctl create CTID –ostemplate osname
# vzctl set CTID –ipadd a.b.c.d –save
# vzctl set CTID –nameserver a.b.c.d –save
# vzctl start CTID
Here CTID is the numeric ID for the container; osname is the name of the OS template for the container, and a.b.c.d is the IP address to be assigned to the container.
Example:
# vzctl create 101 –ostemplate fedora-core-5-minimal
# vzctl set 101 –ipadd 10.1.2.3 –save
# vzctl set 101 –nameserver 10.0.2.1 –save
# vzctl start 101
Installing OpenVZ
OpenVZ is operating system-level virtualization based on a modified Linux kernel that allows a physical server to run multiple isolated instances known as containers, virtual private servers (VPS), or virtual environments (VE).
Installing OpenVZ on a CentOS 4 or CentOS 5
Download - http://download.openvz.org/openvz.repo
Import the OpenVZ key
rpm –import http://download.openvz.org/RPM-GPG-Key-OpenVZ
Install the OpenVZ kernel
Depending on which kernel arch you want, simply do:
yum install ovzkernel.i386
or
yum install ovzkernel.x86_64
Reference - http://download.openvz.org/doc/OpenVZ-Users-Guide.pdf
1) Examine /etc/grub.conf to ensure the desired kernel is set to be the default,
2) Edit the /etc/sysctl.conf to enable some kernel features that are needed for OpenVZ and
3) Make sure SELINUX is disabled.
Resources available for OpenVZ containers.
Resources that can be set, include disk space usage, memory usage, CPU usage, and more.
Restricting and setting hard limits of what is permitted in a container ensures that no tasks within the container can get greedy and steal resources from other containers or the host system itself.
First, look at the vzlist tool. This will provide information on any installed containers which makes managing them simpler vzlist tool
This will provide information on any installed containers which makes managing them simpler:
How to increase the available disk space from 1GB to something more useful like 10GB.
Check disk space.
The above increases the default 1GB drive space available to a barrier of 10GB and a maximum limit of 11GB.
# vzctl set 101 –diskspace 10G:11G –save
# vzctl exec 101 df -hT
There are two ways to change settings for containers. The first is using vzctl as above (remember to use the -save option to make the changes persistent). The second is to edit the configuration file for the container. For a container with a CTID of 101, the file would be /etc/sysconfig/vz-scripts/101.conf.
