LXD Ubuntu: System Container and Virtual Machine Manager
Introduction
LXD is a modern, secure system container and virtual machine manager. It aims to provide a user experience that is both powerful and isolated like virtual machines, while maintaining the lightweight and efficient nature of Linux containers. LXD is built on top of LXC (Linux Containers) and is actively developed and maintained by Canonical (the company behind Ubuntu).
With LXD, you can run multiple isolated Linux systems (containers) on a single host, each with its own environment, resources, and configuration. LXD also supports managing virtual machines, providing users with a unified platform for managing both containers and virtual machines.
Core Concepts
Understanding these core concepts will help you better use LXD:
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Containers: LXD manages system containers, meaning each container runs a complete operating system environment with its own user space, process tree, network interfaces, and filesystem. This differs from application containers (like Docker), which typically only package and run a single application.
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Virtual Machines: In addition to containers, LXD supports managing virtual machines, allowing you to run workloads that require full hardware virtualization under the same management interface.
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Images: Images are pre-built operating system templates used to create new containers or virtual machines. LXD supports multiple image sources, including official Ubuntu images, other Linux distribution images, and community-provided images. You can also create your own custom images.
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Profiles: Profiles are sets of predefined configuration options (such as CPU limits, memory limits, network devices, storage devices, etc.) that can be applied to one or more containers/virtual machines. This makes batch management and standardized configuration easy.
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Storage Pools: Storage pools define how LXD stores container/virtual machine data and images. LXD supports multiple backend storage drivers such as ZFS, Btrfs, LVM, and simple directory drivers.
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Networking: LXD provides flexible network management capabilities, allowing you to configure various types of network interfaces for containers/virtual machines, such as bridge networks, MACVLAN, SR-IOV, etc.
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Snapshots: You can create snapshots of containers or virtual machines to save their state at a specific point in time. Snapshots can be used for backup, recovery, or cloning.
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Clustering: LXD supports grouping multiple LXD hosts into a cluster, enabling unified management, resource sharing, and high availability.
Basic Usage
LXD is primarily managed through the lxc command-line tool. Here are some basic operation examples: