LXD has recently become the next-generation system container manager in Linux. While building on top of the low level LXC, it clearly improves the container orchestration, making administration easier and adding the management of tasks like container migration and the publishing of container images. 

In the realm of cloud computing, system container management solutions have yet to reach the widespread popularity of application container solutions, primarily due to the fact that there is little to no integration with neither private and public cloud management platforms, nor with Kubernetes. But OpenNebula 5.8 “Edge” complements the lack of automation in LXD as a standalone hypervisor and opens up a new set of use cases, especially for large deployments.

When looking at LXD containers as an option for your virtualized infrastructure, and comparing them to “full-fledged” hypervisors, you will see many benefits – the main ones starting with:

• a smaller space footprint and smaller memory
• lack of virtualized hardware
• faster workloads
• faster deployment times 

What do you get with OpenNebula and LXD integration?

It’s great to be able to deploy and utilize these lightweight and versatile LXD containers in your virtual infrastructure.  But the real fireworks start to go off when you contemplate what you’ll get when running OpenNebula on your LXD infrastructure!

As with KVM hypervisors, OpenNebula 5.8 integration with LXD provides advanced features for capacity management, resource optimisation, business continuity, and high availability, offering you complete and comprehensive control over your physical and virtual resources. On top of that, you can manage the provisioning of virtual data centers, creating completely elastic and multi-tenant cloud environments, all from within the simple Sunstone GUI or the available CLI’s. And where you may want to maintain the flexibility of creating a heterogeneous multi-hypervisor environment – clusters of LXD containers alongside clusters of other hypervisors – OpenNebula will manage those resources seamlessly all within the same cloud.

From a compatibility perspective, OpenNebula 5.8 and LXD provides the following:

• Supported storage backends are filesystems with raw and qcow2 devices, and ceph with rbd images. As a result, LXD drivers can use regular KVM images.
• The native network stack is fully compatible.
• The LXD drivers support scenarios with installations both from apt and snap packages. There is also a dedicated marketplace for LXD which is backed by the public image server on https://images.linuxcontainers.org/ where you have access to every officially supported containerized distribution. 

Remember, LXD containers are only suitable for Linux, and share the kernel of the host OS. Also, LXD drivers still lack some functionalities like snapshotting and live migration.  So, being able to create a heterogeneous OpenNebula cloud using both LXD and KVM, wherever necessary, brings the best of both worlds.

OpenNebula 5.8 is “worth writing home about”, and LXD support is certainly one key reason why!