Releases and snap

Releases

The LXD team maintains both Long Term Support (LTS) and feature releases in parallel. Release notes are published on Discourse.

LTS releases

LTS releases are intended for production use.

LXD follows the Ubuntu release cycle cadence, meaning that an LTS release of LXD is created every two years. The release names follow the format x.y.z, always including the point number z. Updates are provided through point releases, incrementing z.

Support

LTS releases receive standard support for five years, meaning that it receives continuous updates according to the support levels described below. An Ubuntu Pro subscription can provide additional support and extends the support duration by an additional five years.

Support levels

Standard support for an LTS release starts at full support for its first two years, then moves to maintenance support for the remaining three years. Once an LTS reaches End of Life (EOL), it no longer receives any updates.

  • Full support: Some new features, frequent bugfixes, and security updates are provided every six months. This schedule is an estimate that can change based on priorities and discovered bugs.

  • Maintenance support: High impact bugfixes and critical security updates are provided as needed.

Currently supported

The currently supported LTS releases are 5.21.z and 5.0.z.

  • 5.21.z is supported until June 2029.

    • Currently in full support phase.

  • 5.0.z is supported until June 2027.

    • Currently in maintenance support phase.

Feature releases

Feature releases are pushed out more often and contain the newest features and bugfixes. Since they are less tested than LTS releases, they are not recommended for production use.

These releases follow the format x.y, and they never include a point number z. Currently, feature releases for LXD are numbered 6.y, with y incrementing for each new release. Every two years, the latest feature release becomes an LTS release.

Support

Feature releases receive continuous updates via each new release. The newest release at any given time is also eligible for additional support through an Ubuntu Pro subscription.

The LXD snap

The recommended way to install LXD is its snap package, if snaps are available for your system. A key benefit of snap packaging is that it includes all required dependencies. This allows LXD to run in a consistent environment on many different Linux distributions. Using the snap also streamlines updates through its channels.

Channels

Each installed LXD snap follows a channel. Channels are composed of a track and a risk level (for example, the 6/stable channel). Each channel points to one release at a time, and when a new release is published to a channel, it replaces the previous one. Updating the snap then updates to that release.

To view all available channels, run:

snap info lxd

Tracks

LXD releases are grouped under snap tracks, such as 6 or 5.21.

LTS tracks

LXD LTS tracks use the format x[.y], corresponding to the major and minor numbers of LTS releases.

Tracks up to 5.21 include both x and y, but future LTS tracks will use only x.

Feature track

The LXD feature track uses the major number of the current feature release. The current feature track is 6.

Feature releases within the same major version are published to the same track, replacing the previous release. For example, the 6.4 release replaced 6.3 in the 6 track. This simplifies updates, as you don’t need to switch channels to access new feature releases within the same major version.

Every two years, the current feature track becomes the next LTS, and a new feature track is then created by incrementing x. For example, after the 6 track becomes an LTS, the 7 track is created and becomes the next feature track.

The default track

If you install the LXD snap without specifying a track, the recommended default is used. The default track always points to the most recent LTS track, which is currently 5.21.

The latest track

In the list of channels shown by snap info lxd, you might see channels with a track named latest. This track typically points to the latest feature release.

Since latest is a continuously rolling release track, it might become incompatible with your host OS version over time. Due to this, this track is not recommended for general use and might be removed in the future. Instead, use a feature or LTS track.

Risk levels

For each LXD track, there are three risk levels: stable, candidate, and edge.

We recommend that you use the stable risk level to install fully tested releases; this is the only risk level supported under Ubuntu Pro, as well as the default risk level if one is not specified at install. The candidate and edge levels offer newer but less-tested updates, posing higher risk.

Updates and upgrades

In this section, find information about updates and upgrades to the LXD snap, as well as about Downgrades.

Updates

To update the LXD snap means to refresh it to the release most recently published to its tracked channel. With the exception of updates published to the latest track, these are always within the same major version. They can be automatically or manually performed.

By default, installed snaps update automatically when new releases are published to the channel they’re tracking. For control over LXD updates, we recommend that you modify this auto-update behavior by either holding or scheduling updates as described in our How to manage the LXD snap guide. You can then apply updates according to your schedule.

Upgrades

To upgrade the LXD snap means to change its channel’s track to a higher version, such as from 5.21 to 6. Such upgrades must be manually performed.

Downgrades

We support the following changes only within the same LTS track:

Due to potential breaking changes, the following are not supported:

Clusters

LXD cluster members must use the same version of the snap at all times. Thus, when updating or upgrading a cluster, the changes must be made to all cluster members. See: Synchronize updates for a LXD cluster cohort and Update or upgrade cluster members.

Database schema update and backup

When the daemon restarts after an LXD update or upgrade, if a new database schema is detected, the database is updated. A backup of the database before the update is created and stored in the same location as the active database. If LXD is installed through the snap, this location is /var/snap/lxd/common/lxd/database. If installed by other means, the location is typically /var/lib/lxd/database/.