systemd-sysext
Manage system extension images
TLDR
Show current merge status
$ systemd-sysext status
List installed extension images$ systemd-sysext list
Merge extensions into /usr and /opt$ systemd-sysext merge
Unmerge all extensions$ systemd-sysext unmerge
Refresh (unmerge then merge)$ systemd-sysext refresh
Merge ignoring version compatibility checks$ systemd-sysext merge --force
SYNOPSIS
systemd-sysext [OPTIONS] COMMAND
DESCRIPTION
systemd-sysext manages system extension images that overlay files onto `/usr/` and `/opt/`. Extensions are read-only images (DDI format) that add software to the base system without modifying the root filesystem.Extensions are stored in `/var/lib/extensions/` or `/run/extensions/` and are merged using overlayfs.
PARAMETERS
--root= PATH
Operate relative to the specified root directory.--force
Ignore version incompatibilities when merging.--mutable= MODE
Set mutability mode (disabled, auto, yes, import, ephemeral, ephemeral-import).--no-reload
Do not reload daemon after merge, unmerge, or refresh.--no-pager
Do not pipe output into a pager.--no-legend
Do not print column headers and footer hints.--json= MODE
Output as JSON (short, pretty, or off).
COMMANDS
status
Show current merge status. Default when invoked without a command.list
List installed extension images.merge
Overlay extension images onto /usr and /opt using overlayfs.unmerge
Remove extension overlays.refresh
Unmerge then merge (reload extensions after installing or removing images).
INSTALL
sudo apt install systemd
sudo dnf install systemd
sudo pacman -S systemd
sudo zypper install systemd
brew install systemd
nix profile install nixpkgs#systemd
CAVEATS
Extensions must match the host OS version. The base /usr must be immutable or read-only for overlay to work. Changes require refresh to take effect.
HISTORY
systemd-sysext enables modular system composition, supporting immutable base images with layered extensions for additional software.
SEE ALSO
systemd-confext(8), systemctl(1), portablectl(1), machinectl(1)
