CentOS 7.x installing lxc

<yambe:breadcrumb>CentOS_7.x_lxc|CentOS 7.x lxc</yambe:breadcrumb>

CentOS 7.x installing lxc

To install lxc use following steps:

1. Install lxc package using

   yum -y install epel-release
   yum -y install debootstrap perl libvirt libcap-devel libcgroup wget bridge-utils
   yum -y install lxc lxc-templates lxc-extra

2. Check that system supports lxc

   lxc-checkconfig

   Before booting a new kernel its support for lxc-can be checked using:

   CONFIG=/boot/config-3.10.0-514.2.2.el7.x86_64 /bin/lxc-checkconfig

   where config-3.10.0-514.2.2.el7.x86_64 should be replaced with configuration file for new kernel

3. Start and enable lxc on boot

   systemctl start lxc.service
   systemctl enable lxc.service
   systemctl status lxc.service

4. Reboot base host for more stability

Refer:

• http://www.tecmint.com/install-create-run-lxc-linux-containers-on-centos/
• http://www.itzgeek.com/how-tos/linux/centos-how-tos/setup-linux-container-with-lxc-on-centos-7-rhel-7.html

Get more space for lxc containers

To get more space for lxc-containers from other partition which by default use /var use following steps: (Replace /mnt/data1 in below steps and commands with mount-point where more space is available in your installation)

1. Stop all running containers. Verify 'lxc-ls --active'
2. mkdir /mnt/data1/lxc-files
3. mkdir /mnt/data1/lxc-files/{var_cache_lxc,var_lib_lxc}
4. mv /var/cache/lxc/* /mnt/data1/lxc-files/var_cache_lxc/

   The above command can generate "No such file or directory" error if the cache is empty. This is likely on a new machine where no container has been created yet.

5. rmdir /var/cache/lxc
6. ln -s /mnt/data1/lxc-files/var_cache_lxc/ /var/cache/lxc
7. mv /var/lib/lxc/* /mnt/data1/lxc-files/var_lib_lxc/

   The above command can generate "No such file or directory" error if the lib_lxc folder is empty. This is possible if there are no containers running or stopped on current machine.

8. rmdir /var/lib/lxc
9. ln -s /mnt/data1/lxc-files/var_lib_lxc/ /var/lib/lxc
10. lxc-ls
11. Start a few containers and test

Additional configuration

After basic installation and getting more space for lxc containers consider doing:

• Disable SELinux
• CentOS 7.x lxc container networking or

  Creating bridge interfaces (br0) for virtual hosts to use shared interface

• Read CentOS 7.x lxc container hanging issue and create centos containers accordingly.
• CentOS 7.x lxc package installation issue
• Issue CentOS 7.x 100% CPU usage issue with CentOS7 or fedora lxc containers does not seems to happen on new installations so the correponding change may not be required in new installations.

<yambe:breadcrumb>CentOS_7.x_lxc|CentOS 7.x lxc</yambe:breadcrumb>