Install and Use LXD on on Rocky / AlmaLinux 8|9

LXD is a next generation system container manager built around a very powerful REST and offers a user experience similar to virtual machines but using Linux containers instead. LXD uses pre-made Linux images which are available for a wide number of Linux distributions.

In this guide, I’ll show you simple steps to install and use LXD on Rocky / AlmaLinux server/Desktop. The installation will make use of Snap, which was covered on Installing Snapd and Snap applications on Rocky / AlmaLinux guide.

Features of LXD

From the official LXD website, these are the biggest features of LXD are mentioned:

• Secure by design (unprivileged containers, resource restrictions and much more)
• Scalable (from containers on your thousands thousand of compute nodes)
• Intuitive (simple, clear API and crisp command line experience)
• Image-based (with a wide variety of Linux distributions published daily)
• Support for Cross-host container and image transfer (including live migration with CRIU)
• Advanced resource control (cpu, memory, network I/O, block I/O, disk usage and kernel resources)
• Device passthrough (USB, GPU, Unix character and block devices, NICs, disks, and paths)
• Network management (bridge creation and configuration, cross-host tunnels, …)
• Storage management (support for multiple storage backends, storage pools, and storage volumes)

Running LXD Containers on on Rocky / AlmaLinux

Now let’s start the installation of LXD on Rocky / AlmaLinux by following the steps below

Step 1: Install snapd

You need to install snapd which will provide snap command line tool used to install LXD package. Install snapd by following the guide:

• Installing Snapd and Snap applications on Rocky / AlmaLinux

Once you have snapd installed, go to step 2

Step 2: Configure Kernel Parameters

Some Kernel options are required by LXD to be enabled on the system. Configure them by running the following commands on your terminal. Run these commands as root user.

grubby --args="user_namespace.enable=1" --update-kernel="$(grubby --default-kernel)"
grubby --args="namespace.unpriv_enable=1" --update-kernel="$(grubby --default-kernel)"
echo "user.max_user_namespaces=3883" > /etc/sysctl.d/99-userns.conf

You’ll need to reboot the system after making the changes.

sudo reboot

Step 3: Install lxd snap on Rocky / AlmaLinux

Finally, install LXD snap from snap store

$ sudo snap install lxd
lxd (5.21/stable) 5.21.1-d46c406 from Canonical✓ installed

The installation should take short time if you have a good internet connection. You can confirm package installation using:

$ sudo snap list
Name        Version         Rev    Tracking       Publisher              Notes
core20      20240416        2318   latest/stable  canonical✓             base
core22      20240408        1380   latest/stable  canonical✓             base
lxd         5.21.1-d46c406  28460  5.21/stable    canonical✓             -
powershell  7.4.3           269    latest/stable  microsoft-powershell✓  classic
snapd       2.63            21759  latest/stable  canonical✓             snapd

$ sudo snap services
Service          Startup  Current   Notes
lxd.activate     enabled  inactive  -
lxd.daemon       enabled  inactive  socket-activated
lxd.user-daemon  enabled  inactive  socket-activated

Step 4: Launching test LXD container

Ensure

echo 'export PATH="$PATH:/snap/bin/"'|tee -a  ~/.bashrc
source ~/.bashrc

Let’s add our user account to the grouplxd for it to manage LXD containers without permission errors.

sudo usermod -aG lxd $USER
newgrp lxd

Load kernel modules.

sudo modprobe overlay
sudo modprobe br_netfilter

Ensure modules are configured to load at boot:

echo -e "noverlay\nbr_netfilter" | sudo tee /etc/modules-load.d/lxd.conf

Restart LXD service.

sudo systemctl restart snap.lxd.daemon

Configure LXD environment using

$ lxd init
Would you like to use LXD clustering? (yes/no) [default=no]: no
Do you want to configure a new storage pool? (yes/no) [default=yes]: no
Name of the new storage pool [default=default]: 
Name of the storage backend to use (btrfs, ceph, dir, lvm) [default=btrfs]: dir 
Would you like to connect to a MAAS server? (yes/no) [default=no]: 
Would you like to create a new local network bridge? (yes/no) [default=yes]: 
What should the new bridge be called? [default=lxdbr0]: 
What IPv4 address should be used? (CIDR subnet notation, “auto” or “none”) [default=auto]: 
What IPv6 address should be used? (CIDR subnet notation, “auto” or “none”) [default=auto]: 
Would you like LXD to be available over the network? (yes/no) [default=no]: 
Would you like stale cached images to be updated automatically? (yes/no) [default=yes] 
Would you like a YAML "lxd init" preseed to be printed? (yes/no) [default=no]:

A listing of containers should return an empty list

$ lxc list
+------+-------+------+------+------+-----------+
| NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS |
+------+-------+------+------+------+-----------+

To list available VM images run:

lxc image list images:

Example of image names available:

• fedora/40
• kali
• rockylinux/9
• rockylinux/8
• oracle/9
• almalinux/8
• almalinux/9

# Rocky linux 8|9
lxc image list images:centos/9-Stream
debian/12

Create a test Rocky Linux 8 container by running:

# lxc launch images:rockylinux/8 rocky-8-container
Creating rocky-8-container
Starting rocky-8-container

Launch Ubuntu container by running:

# lxc launch images:ubuntu/22.04 ubuntu-container
Creating ubuntu-container
Starting ubuntu-container

List your containers:

# lxc list
+-------------------+---------+-----------------------+-----------------------------------------------+-----------+-----------+
|       NAME        |  STATE  |         IPV4          |                     IPV6                      |   TYPE    | SNAPSHOTS |
+-------------------+---------+-----------------------+-----------------------------------------------+-----------+-----------+
| rocky-8-container | RUNNING | 10.249.233.129 (eth0) | fd42:380b:91a6:efc0:216:3eff:fece:1ee3 (eth0) | CONTAINER | 0         |
+-------------------+---------+-----------------------+-----------------------------------------------+-----------+-----------+
| ubuntu22          | RUNNING | 10.249.233.40 (eth0)  | fd42:380b:91a6:efc0:216:3eff:feb1:7d6f (eth0) | CONTAINER | 0         |
+-------------------+---------+-----------------------+-----------------------------------------------+-----------+-----------+
| ubuntu-container  | RUNNING | 10.249.233.189 (eth0) | fd42:380b:91a6:efc0:216:3eff:fe6f:7d3e (eth0) | CONTAINER | 0         |
+-------------------+---------+-----------------------+-----------------------------------------------+-----------+-----------+

Stop, start, restart, delete, check info a container

lxc start container
lxc stop container
lxc restart container

Get info about a container using info command option

lxc info container

Sample output:

For more command line options, run

lxc --help
lxc command --help e.g lxc start --help

Recommended Linux Books  to read:

• Best Linux Books for Beginners & Experts
• Best Linux Kernel Programming Books
• Best Linux Bash Scripting Books

You have successfully installed LXD on Rock / AlmaLinux from snap and created an lxc container. Thanks for using our guide. If you have any issue, don’t hesitate to drop a comment.