LXC (Linux containers)¶

LXC (also known as Linux containers) is a virtualization technology that works at the operating system level. This is different from hardware virtualization, the approach used by other hypervisors such as KVM, Xen, and VMware. LXC (as currently implemented using libvirt in the Compute service) is not a secure virtualization technology for multi-tenant environments (specifically, containers may affect resource quotas for other containers hosted on the same machine). Additional containment technologies, such as AppArmor, may be used to provide better isolation between containers, although this is not the case by default. For all these reasons, the choice of this virtualization technology is not recommended in production.

If your compute hosts do not have hardware support for virtualization, LXC will likely provide better performance than QEMU. In addition, if your guests must access specialized hardware, such as GPUs, this might be easier to achieve with LXC than other hypervisors.

To enable LXC, ensure the following options are set in /etc/nova/nova.conf on all hosts running the nova-compute service.

compute_driver = libvirt.LibvirtDriver

[libvirt]
virt_type = lxc

On Ubuntu, enable LXC support in OpenStack by installing the nova-compute-lxc package.