Argent SystemD Services

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Argent SystemD Services

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. It also looks up .local names, but never announces yours, see below sys-apps/systemd
avahi-daemon.service and .socket announces your computer as hostname.local, and 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
systemd-timesyncd.service keeps your clock right, over the network sys-apps/systemd
virtualbox-guest-additions.service VirtualBox guest tools, only if you installed Argent 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

The sound is a user service

PipeWire and WirePlumber run only as a user service, for the user who is logged in on the desktop. Never ever as a system service, and never ever for root:

  • don't enable them with systemctl enable (without --user), there is no system-wide PipeWire on Argent
  • don't enable them for root: PipeWire refuses to run as root (ConditionUser=!root), and WirePlumber then fails with Bound to unit pipewire.service, but unit isn't active
  • don't run programs that play sound as root, run them as your user

On Argent they are already enabled for every user the installer creates. For a user you add later, enable them once, as that user:

systemctl --user enable --now pipewire.socket pipewire-pulse.socket wireplumber.service

To check that the sound works for your user:

systemctl --user status pipewire wireplumber

wpctl status

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

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

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

What the installer changes

The live ISO needs some services that your installed system doesn't. At the end of the installation, the installer (Calamares) fixes that for you:

  • enables systemd-timesyncd.service, so your clock stays right
  • removes the leftover link of argentlive.service, which is removed together with app-misc/argent-live
  • disables argent-config-vbox.service
  • removes app-emulation/virtualbox-guest-additions and app-emulation/virtualbox-guest-modules, unless you are installing inside VirtualBox, where you need them

Installed from an older ISO?

If you installed Argent from an ISO older than 1.5.3-RC9, do these by hand, once, as root:

timedatectl set-ntp true

rm -f /etc/systemd/system/multi-user.target.wants/argentlive.service

systemctl disable argent-config-vbox.service

And, only if your Argent is not running inside VirtualBox:

epkg remove app-emulation/virtualbox-guest-additions app-emulation/virtualbox-guest-modules

Without that last one, you get a popup at every login: VBoxClient: the VirtualBox kernel service is not running. Exiting.

Older ISOs also enabled PipeWire for root, which PipeWire never allows. It only shows as wireplumber.service: Bound to unit pipewire.service, but unit isn't active in the log when root logs in, your sound is not affected. To clean it up:

rm -rf /root/.config/systemd/user/default.target.wants/pipewire.service /root/.config/systemd/user/pipewire.service.wants /root/.config/systemd/user/sockets.target.wants/pipewire*.socket /root/.config/systemd/user/pipewire-session-manager.service

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 keeps your clock in sync with systemd-timesyncd, the installer turns it on. timedatectl shows you if your clock is synced:

timedatectl

If it says NTP service: inactive, turn it on:

timedatectl set-ntp true

SSD TRIM: fstrim.timer

Here comes the old defrag times to modern 2020s.

An SSD or NVMe drive must be told which blocks the filesystem doesn't use anymore, that's what TRIM does. Without it, the drive thinks it is always full: over the months writes get slower, and the desktop freezes for a moment whenever a program saves something. A live ISO doesn't pass through this, because it writes only to RAM, so that's why you feel a much proper experience on a LIVE medium than installed over time.

But we at Argent don't turn TRIM on for you yet, though. We just want to let you know that sys-apps/util-linux brings fstrim.timer, which trims every mounted filesystem listed in /etc/fstab, once a week.

To see if it's on:

systemctl list-timers fstrim.timer

To see if your drive supports TRIM (DISC-GRAN and DISC-MAX are not zero):

lsblk --discard

The first time, trim by hand, as root:

fstrim -v /

On a drive that was never trimmed this can take a minute or more, the desktop may freeze for a few seconds, and some laptops make a high-pitched whine while the drive works. That's normal (we think?), it stops when fstrim is done. It only manages free space, your files are safe. At the end it tells you how much it trimmed, for example /: 368.8 GiB (395969245184 bytes) trimmed.

Then turn on the weekly timer:

systemctl enable --now fstrim.timer

By default it runs every Monday at 00:00, plus a random delay of up to 100 minutes. If the computer is off then, it runs at the next boot.

To pick another day, for example Thursday at 00:00:

systemctl edit fstrim.timer 

[Timer]
OnCalendar=
OnCalendar=Thu *-*-* 00:00:00

The empty OnCalendar= line clears the Monday default, without it the timer runs on both days. Then:

systemctl restart fstrim.timer

systemctl list-timers fstrim.timer

NEXT must show the next Thursday. To see what each run trimmed:

journalctl -u fstrim.service

Don't add discard to the mount options in /etc/fstab instead: then every file you delete is trimmed right away, and on many SATA SSDs the disk pauses on every delete. Once a week is enough.

Your Argent current network settings: avahi and systemd-resolved

Two services on Argent know about names on your local network:

  • avahi announces your computer on the network as hostname.local, and finds printers, network shares and other computers. CUPS, KDE and PipeWire all use it
  • systemd-resolved is the DNS of your system, every program asks it to turn names into addresses. It also looks up .local names, so ssh nas.local or http://printer.local work

Both of them can announce your computer's name, but only one of them should. When both do it, they see each other's announcement as a conflict, and systemd-resolved starts renaming your computer on the network, over and over: gent, gent9, gent11, gent15, ... hundreds of times per boot.

So on Argent, avahi is the only one that announces, and systemd-resolved only looks names up. It's set in:

/etc/systemd/resolved.conf.d/00-argent.conf 

[Resolve]
MulticastDNS=resolve
LLMNR=no
  • MulticastDNS=resolve: look up .local names, but never announce ours
  • LLMNR=no: no LLMNR, the Windows style name announcing, which renames itself the same way. Windows is dropping it anyway

This file comes with app-misc/argent-config-files. To check that it's active:

resolvectl status

It must say -LLMNR mDNS=resolve. If you just upgraded and it doesn't, restart it:

systemctl restart systemd-resolved

To see if your computer was renamed on the network during this boot:

journalctl -b | grep -i "hostname conflict"

Don't disable avahi-daemon: without it, nobody announces your computer, and your printers are not found anymore.

KDE Connect has its own name announcing built in, and it can fight with avahi the same way (KDE bug 487719). If you installed KDE Connect and your computer gets renamed to hostname-2.local, that's the reason.

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 has priority 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, except systemd-resolved, see above.

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.

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