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linux:systemd [2016/04/06 09:38] – niziaklinux:systemd [2024/02/09 19:24] (current) – niziak
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 +====== systemd ======
 +
 +  * [[https://www.freedesktop.org/software/systemd/man/latest/bootup.html|bootup — System bootup process]]
 +
 ===== HowTo ===== ===== HowTo =====
 ==== start / stop ==== ==== start / stop ====
 +Rerun all generators, reload all unit files and recreate dependency tree:
 <code bash> <code bash>
 systemctl daemon-reload systemctl daemon-reload
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 </code> </code>
  
 +<code bash>
 +systemd-cgtop
 +</code>
  
 ==== emergency mode  ==== ==== emergency mode  ====
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 <code>setenv bootargs ${bootargs} systemd.unit=emergency.target</code> <code>setenv bootargs ${bootargs} systemd.unit=emergency.target</code>
  
-=== Start service when MMC card is inserted ===+Enable debug console on tty9 
 +<code bash>systemctl enable debug-shell.service</code> 
 + 
 +==== Start service when MMC card is inserted ====
 Create directory "dev-mmcblk0.device.wants" and put symlink to service inside it. Create directory "dev-mmcblk0.device.wants" and put symlink to service inside it.
 List of devices: <code bash>systemctl --all --full -t device</code> List of devices: <code bash>systemctl --all --full -t device</code>
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 === Remove startup console clearing === === Remove startup console clearing ===
-<code> +<file | /etc/systemd/system/getty@tty1.service.d/noclear.conf>
-/etc/systemd/system/getty@tty1.service.d/noclear.conf+
  
 [Service] [Service]
 TTYVTDisallocate=no TTYVTDisallocate=no
 +</file>
 +
 +=== udev ===
 +In udev rules.d add TAG+="systemd":
 +<code>
 +SUBSYSTEM=="input", KERNEL=="event[0-9]*", ENV{ID_INPUT_TOUCHSCREEN}=="1", ATTRS{name}=="edt-ft53*", \
 +    SYMLINK+="input/lcd_sandwich_touchscreen input/touchscreen_edt", \
 +    TAG+="systemd", \
 +    OPTIONS+="link_priority=100"
 </code> </code>
 +And now device is visible from systemd:
 +<code bash>
 +systemctl -l -a
 +  dev-input-event0.device                                                                        loaded    active   plugged   /dev/input/event0
 +  dev-input-lcd_sandwich_touchscreen.device                                                      loaded    active   plugged   /dev/input/lcd_sandwich_touchscreen
 +</code>
 +You can create refer to device, e.g. create .wants directory
 +<code>/etc/systemd/system/ev-input-lcd_sandwich_touchscreen.device.wants</code>
 +
 +=== udev: start service ===
 +To start service if device is inserted:
 +<file | mu.rule>
 +..., TAG+="systemd", ENV{SYSTEMD_WANTS}="netctl-auto@mywifi.service"
 +</file>
 +
 +=== do not mount crypted volumes ===
 +After switching to systemd by command <code bash>apt-get install systemd-sysv</code>, new problem occurs: 
 +system boot stops and waits for password for encrypted partition (with user data - no needed to system start).
 +
 +To prevent automount of crypted volumes, additional parameters 'noauto' and 'noearly' must be added to /etc/crypttab:
 +<file | /etc/crypttab>
 +/MyMountPoint /dev/vg_MyName/lv_MyName none luks,noauto,noearly
 +</file>
 +
 +=== Debian: Set network service timeout ===
 +System startup can hang forever if there is no link on ethernet cable:
 +<code>[    **] A start job is running for LSB: Raise network interf...38s / no limit)</code>
 +To set timeout, add file:
 +<file | /etc/systemd/system/networking.service.d/reduce-timeout.conf>
 +[Service]
 +TimeoutStartSec=15
 +</file>
 +
 +====== Issues ======
 +
 +===== init.d services not started =====
 +
 +<code>
 +systemd-sysv-generator[320]: stat() failed on /etc/init.d/traccar, ignoring: No such file or directory
 +systemd-sysv-generator[320]: stat() failed on /etc/init.d/ts3server, ignoring: No such file or directory
 +systemd-sysv-generator[320]: stat() failed on /etc/init.d/miio_server, ignoring: No such file or directory
 +</code>
 +
 +Reason is that some init scripts are symlinked to files located in **/opt** directory, which is a different FS (in this case BTRFS subvolume), and it was not mounted when **systemd-sysv-generator** was started.
 +
 +**Solution:**
 +[[https://access.redhat.com/solutions/3094591|How to mount non-root filesystem before systemd-sysv-generator runs?]]
 +
 +> Under systemd-enabled systems, there's a new-with-systemd mount-option you can place in ''/etc/fstab'' — **x-initrd.mount**. 
 +> You also need to make sure that your filesystem's fs_passno is set to "0" ...and if your filesystem lives on an LVM2 volume, you need to update your GRUB2 config to ensure that the LVM gets onlined prior to systemd invoking the systemd-sysv-generator utility
 +
 +
 +