2.2.20 Linux Containers

The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.

2.2.20 Linux Containers

The Linux Containers package (lxc) is available for the x86-64 architecture with UEK R3 but not i386.
The correct operation of containers might require that you completely disable SELinux on the host system. For example, SELinux can interfere with container operation under the following conditions:
- Running the halt or shutdown command from inside the container hangs the container or results in a permission denied error. (An alternate workaround is to use the init 0 command from inside the container to shut it down.)
- Setting a password inside the container results in a permission denied error, even when run as root.
- You want to allow ssh logins to the container. ssh logins are possible with SELinux enabled if you install the lxc-0.9.0-2.0.5 package (or later version of this package).
To disable SELinux on the host:
1. Edit the configuration file for SELinux, /etc/selinux/config and set the value of the SELINUX directive to disabled.
2. Shut down and reboot the host system.
The default location for a container's configuration has changed from /etc/lxc/name to /container/name in lxc 0.8.0 onward.
To start a container that you created with a previous update of Oracle Linux, specify the -f option to lxc-start, for example:
```
# lxc-start -n ol6u3 -f /etc/lxc/ol6u3/config
```
To convert an existing container to use the new location:
1. Move the container's configuration directory to /container/name:
```
# mv /etc/lxc/name /container 
```
2. Edit the /container/name/config file and change the values of any lxc.rootfs and lxc.mount parameters to refer to /container instead of /etc/lxc.
  For example, the config file might contain the following entries:
```
lxc.rootfs = /etc/lxc/example/rootfs
lxc.mount.entry=/lib /etc/lxc/example/rootfs/lib none ro,bind 0 0
lxc.mount.entry=/usr/lib /etc/lxc/example/rootfs/usr/lib none ro,bind 0 0
lxc.mount.entry=/lib64 /etc/lxc/example/rootfs/lib64 none ro,bind 0 0
lxc.mount.entry=/usr/lib64 /etc/lxc/example/rootfs/usr/lib64 none ro,bind 0 0
```
  You would change these entries to read:
```
lxc.rootfs = /container/example/rootfs
lxc.mount.entry=/lib /container/example/rootfs/lib none ro,bind 0 0
lxc.mount.entry=/usr/lib /container/example/rootfs/usr/lib none ro,bind 0 0
lxc.mount.entry=/lib64 /container/example/rootfs/lib64 none ro,bind 0 0
lxc.mount.entry=/usr/lib64 /container/example/rootfs/usr/lib64 none ro,bind 0 0
```
After converting the container, you do not need to specify the -f option to lxc-start. (Bug ID 15967411)
Attempting to create an lxc-oracle container on a remote file system mounted using NFS v4 fails. In addition, attempting to mount a remote file system using NFS v4 from within an lxc-oracle container also fails. The workaround is to use NFS v3 instead. (Bug ID 16316266)