Argent SystemD Services

Systemd on Argent

Argent runs on systemd, the Gentoo profile is default/linux/amd64/23.0/desktop/plasma/systemd. There is no OpenRC: our make.conf disables the openrc and sysvinit USE flags, and /etc/init.d is not even installed (INSTALL_MASK).

So everything the Gentoo and systemd documentation says applies to Argent too:

• Gentoo wiki: systemd
• the man pages that come with systemd, on your system: man systemctl, man journalctl, man systemd.unit, man systemd.service, man systemd.timer

The tools you will use, all part of systemd:

• systemctl: start, stop, enable, disable and look at services
• journalctl: read the logs
• systemd-analyze: boot time, and what slows it down
• coredumpctl: programs that crashed
• timedatectl, hostnamectl, localectl, resolvectl, loginctl: time, hostname, keyboard and language, DNS, sessions

This page explains what Argent runs, and how you manage it.

What runs on a fresh Argent

System services

These are enabled on an installed Argent:

Service	What it does	Package
sddm.service	the login screen, also known as display-manager.service	x11-misc/sddm
NetworkManager.service	the network (wired, wireless, VPN)	net-misc/networkmanager
NetworkManager-dispatcher.service	runs scripts when the network changes	net-misc/networkmanager
NetworkManager-wait-online.service	makes network-online.target wait for the network	net-misc/networkmanager
ModemManager.service	mobile broadband modems	net-misc/modemmanager
systemd-resolved.service	DNS, /etc/resolv.conf points to it	sys-apps/systemd
avahi-daemon.service and .socket	finds printers and other machines on your network (mDNS)	net-dns/avahi
cups.service, .socket and .path	printing	net-print/cups
lvm2-monitor.service	LVM monitoring	sys-fs/lvm2
argent-config-vbox.service	loads the VirtualBox video driver before the login screen	app-misc/argent-config-files
virtualbox-guest-additions.service	VirtualBox guest tools, it starts only inside VirtualBox	app-emulation/virtualbox-guest-additions
getty@tty1.service	the text console on tty1	sys-apps/systemd

The default target is graphical.target, so Argent boots straight to the login screen.

Some services are not enabled, but still run: they are started on demand, by D-Bus, when a program asks for them. For example polkit, udisks2 (disks), upower (battery) and power-profiles-daemon (power profiles). Leave them alone.

User services

Every user who logs in gets their own systemd, with their own services. On Argent:

• the sound: pipewire.service, pipewire-pulse.service and wireplumber.service, enabled for each user. PipeWire replaces PulseAudio
• the whole Plasma desktop runs as user services: plasma-plasmashell.service, plasma-kwin_wayland.service, plasma-powerdevil.service and so on

To see them, as your user (not root):

systemctl --user list-units --type=service

Timers

Argent has no cron daemon, systemd timers do that job. Out of the box there is only systemd-tmpfiles-clean.timer, which cleans temporary files daily. To see all of them:

systemctl list-timers --all

Argent's own services

• argent-config-vbox.service, from app-misc/argent-config-files: runs modprobe vboxvideo before sddm, so the login screen works in VirtualBox
• argentlive.service: only on the live ISO, it prepares the live session. It is not installed on your system

The live ISO also enables connman, dkms, dm-event and lvm2-lvmetad when they are there, see the avasile page (--makeiso).

Managing services

Everything below needs root, except the --user commands, which you run as your own user.

To see how a service is doing, with its last log lines:

systemctl status NetworkManager

To start, stop or restart it now:

systemctl start cups

systemctl stop cups

systemctl restart cups

To start it at every boot (enable), or not anymore (disable). --now also starts or stops it right away:

systemctl enable --now sshd

systemctl disable --now sshd

To make sure a service never starts, not even when something else asks for it:

systemctl mask ModemManager

systemctl unmask ModemManager

To see what is enabled, and what failed:

systemctl list-unit-files --state=enabled

systemctl --failed

For your own user services, add --user, as your user:

systemctl --user restart pipewire

Installing a package with a service

On Gentoo, and so on Argent, installing a package never enables its service. That's why systemctl status shows preset: disabled next to almost everything. You install, then you enable:

epkg install net-misc/openssh

systemctl enable --now sshd

The same when you remove a package: disable its service first.

systemctl disable --now sshd

epkg remove net-misc/openssh

Time synchronization

Argent doesn't enable time synchronization by default. timedatectl shows you if your clock is synced:

timedatectl

To turn it on (it uses systemd-timesyncd, already installed with systemd):

timedatectl set-ntp true

Logs

The logs are kept by systemd-journald, in /var/log/journal, so they survive a reboot.

The logs of one service:

journalctl -u NetworkManager

Follow them live:

journalctl -u NetworkManager -f

Everything since the last boot, or from the boot before:

journalctl -b

journalctl -b -1

Only the errors since the last boot:

journalctl -b -p err

How much space the logs take, and how to shrink them:

journalctl --disk-usage

journalctl --vacuum-size=200M

Where the unit files live

Directory	What is there	Yours?
/usr/lib/systemd/system/	system services installed by packages	no, overwritten at every upgrade
/etc/systemd/system/	the enable links, your overrides, your own services	yes
/usr/lib/systemd/user/	user services installed by packages	no
/etc/systemd/user/	user services for all users	yes
~/.config/systemd/user/	user services only for you	yes

What is in /etc wins over what is in /usr/lib. So never edit a file in /usr/lib/systemd, the next epkg upgrade puts it back. Override it in /etc instead.

After you change any unit file by hand, tell systemd:

systemctl daemon-reload

Changing an installed service

systemctl edit opens an editor with an empty override (a "drop-in"). You write only what you want to change, and it is saved in /etc/systemd/system/<service>.d/override.conf, so it survives upgrades:

systemctl edit cups

For example, to restart cups whenever it crashes:

[Service]
Restart=on-failure
RestartSec=5s

To see the service together with your changes:

systemctl cat cups

To throw your changes away and go back to the package's version:

systemctl revert cups

Adding your own service

Say you have a script, /usr/local/bin/my-backup.sh, that you want systemd to run. Create /etc/systemd/system/my-backup.service:

[Unit]
Description=My backup
After=network-online.target
Wants=network-online.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/my-backup.sh

[Install]
WantedBy=multi-user.target

Then:

systemctl daemon-reload

systemctl enable --now my-backup.service

For something that keeps running (a server, a daemon), use Type=simple and add Restart=on-failure. man systemd.service has all the options.

Running it on a schedule

Instead of cron, a timer with the same name as the service. Create /etc/systemd/system/my-backup.timer:

[Unit]
Description=My backup, every night

[Timer]
OnCalendar=*-*-* 02:00:00
Persistent=true

[Install]
WantedBy=timers.target

Persistent=true means that if the machine was off at 02:00, the backup runs at the next boot. Then enable the timer, not the service:

systemctl daemon-reload

systemctl disable my-backup.service

systemctl enable --now my-backup.timer

systemctl list-timers

A service for your user only

The same, but in ~/.config/systemd/user/, with WantedBy=default.target, and with --user, as your user:

systemctl --user daemon-reload

systemctl --user enable --now my-sync.service

It starts when you log in, and stops when you log out.

Configuring systemd itself

systemd's own settings are in /etc/systemd/: journald.conf, logind.conf, resolved.conf, system.conf, sleep.conf, ... On Argent they are all left at the systemd defaults.

Don't edit those files, add a drop-in next to them. For example, to keep the logs under 500 MB, create /etc/systemd/journald.conf.d/100-my.conf:

[Journal]
SystemMaxUse=500M

systemctl restart systemd-journald

Every file has its man page: man journald.conf, man logind.conf, man resolved.conf, ...

When something goes wrong

What failed:

systemctl --failed

Why it failed:

systemctl status <service>

journalctl -u <service> -b

What crashed:

coredumpctl list

coredumpctl info <PID>

Why the boot is slow:

systemd-analyze

systemd-analyze blame

systemd-analyze critical-chain

If you ask for help on our channels, bring the output of systemctl --failed and journalctl -b -p err.