systemd-sysext

Manage system extension images

TLDR

List extension images

$ systemd-sysext list

Merge extensions into /usr and /opt

$ systemd-sysext merge

Check status

$ systemd-sysext status

Unmerge all extensions

$ systemd-sysext unmerge

Refresh (unmerge and merge)

$ systemd-sysext refresh

SYNOPSIS

systemd-sysext [OPTIONS] COMMAND

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.

COMMANDS

list

List installed extension images

merge

Overlay extension images onto /usr and /opt

unmerge

Remove extension overlays

status

Show current merge status

refresh

Unmerge then merge (reload extensions)

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.