Linux systemd单元启动配置及日志之sysinit.target

apparmor.service

AppArmor is a kernel enhancement to confine programs to a limited set of resources. AppArmor's unique security model is to bind access control attributes to programs rather than to users.
    ExecStart=/etc/init.d/apparmor start
    
    # journalctl -b -u apparmor.service
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:17:01 CST. --
    9月 26 09:17:32 eric-vm-dev apparmor[406]:  * Starting AppArmor profiles
    9月 26 09:17:32 eric-vm-dev apparmor[406]: Skipping profile in /etc/apparmor.d/disable: usr.bin.firefox
    9月 26 09:17:32 eric-vm-dev apparmor[406]: Skipping profile in /etc/apparmor.d/disable: usr.sbin.rsyslogd
    9月 26 09:17:32 eric-vm-dev apparmor[406]:    ...done.
    9月 26 09:17:13 eric-vm-dev systemd[1]: Starting AppArmor initialization...
    9月 26 09:17:29 eric-vm-dev systemd[1]: Started AppArmor initialization.

dev-hugepages.mount

    Huge Pages File System
    Where=/dev/hugepages

dev-mqueue.mount

    POSIX message queues allow processes to exchange data in the form of messages.  This API is distinct from that provided by System V message queues (msgget(2), msgsnd(2), msgrcv(2), etc.), but provides similar functionality.
    Where=/dev/mqueue

kmod-static-nodes.service

    Create list of required static device nodes for the current kernel
    ExecStart=/bin/kmod static-nodes --format=tmpfiles --output=/run/tmpfiles.d/kmod.conf

plymouth-read-write.service

    Tell Plymouth To Write Out Runtime Data
    ExecStart=-/bin/plymouth update-root-fs --read-write
    
    # journalctl -b -u plymouth-read-write.service
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:17:01 CST. --
    9月 26 09:17:13 eric-vm-dev systemd[1]: Starting Tell Plymouth To Write Out Runtime Data...
    9月 26 09:17:13 eric-vm-dev systemd[1]: Started Tell Plymouth To Write Out Runtime Data.

proc-sys-fs-binfmt_misc.automount

    Arbitrary Executable File Formats File System Automount Point
    Where=/proc/sys/fs/binfmt_misc
    
    # journalctl -b -u proc-sys-fs-binfmt_misc.automount
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:17:01 CST. --
    9月 26 09:17:13 eric-vm-dev systemd[1]: proc-sys-fs-binfmt_misc.automount: Got automount request for /proc/sys/fs/binfmt_misc, triggered by 405 (update-binfmts)
systemd-binfmt.service:
    an early boot service that registers additional binary formats for executables in the kernel.
    ExecStart=/lib/systemd/systemd-binfmt

sys-fs-fuse-connections.mount

    FUSE Control File System
    Where=/sys/fs/fuse/connections
    
    # journalctl -b -u sys-fs-fuse-connections.mount
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:17:01 CST. --
    9月 26 09:17:12 eric-vm-dev systemd[1]: Mounting FUSE Control File System...
    9月 26 09:17:12 eric-vm-dev systemd[1]: Mounted FUSE Control File System.

sys-kernel-config.mount

    Kernel Configuration File System
    Documentation=https://www.kernel.org/doc/Documentation/filesystems/configfs/configfs.txt
    Where=/sys/kernel/config
    
    # journalctl -b -u sys-kernel-config.mount
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:17:01 CST. --
    9月 26 09:17:12 eric-vm-dev systemd[1]: Mounting Kernel Configuration File System...
    9月 26 09:17:12 eric-vm-dev systemd[1]: Mounted Kernel Configuration File System.

sys-kernel-debug.mount

    Kernel Debug File System
    Documentation=https://www.kernel.org/doc/Documentation/filesystems/debugfs.txt
    Where=/sys/kernel/debug
    
    # journalctl -b -u sys-kernel-debug.mount
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:17:01 CST. --
    9月 26 09:17:11 eric-vm-dev systemd[1]: Mounted Kernel Debug File System.

systemd-hwdb-update.service

    Rebuild Hardware Database
    ExecStart=/bin/systemd-hwdb update

systemd-journald.service

    a system service that collects and stores logging data. It creates and maintains structured, indexed journals based on logging information that is received from a variety of sources
    ExecStart=/lib/systemd/systemd-journald
    
    # journalctl -b -u systemd-journald.service
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:17:01 CST. --
    9月 26 09:17:11 eric-vm-dev systemd-journald[353]: Journal started
    9月 26 09:17:11 eric-vm-dev systemd-journald[353]: Runtime journal (/run/log/journal/266fb8dd63684e13990aaa34604dc5c8) is 2.4M, max 19.6M, 17.2M free.
    9月 26 09:17:12 eric-vm-dev systemd-journald[353]: Time spent on flushing to /var is 1.672395s for 1578 entries.
    9月 26 09:17:12 eric-vm-dev systemd-journald[353]: System journal (/var/log/journal/266fb8dd63684e13990aaa34604dc5c8) is 720.1M, max 4.0G, 3.2G free.

systemd-machine-id-commit.service

    an early boot service responsible for committing transient /etc/machine-id files to a writable disk file system
    ExecStart=/bin/systemd-machine-id-setup --commit

systemd-modules-load.service

    an early boot service that loads kernel modules based on static configuration.
    ExecStart=/lib/systemd/systemd-modules-load
    KERNEL COMMAND LINE: modules_load=, rd.modules_load=
    
    # journalctl -b -u systemd-modules-load.service
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:17:01 CST. --
    9月 26 09:17:11 eric-vm-dev systemd-modules-load[352]: Inserted module 'lp'
    9月 26 09:17:11 eric-vm-dev systemd-modules-load[352]: Inserted module 'ppdev'
    9月 26 09:17:11 eric-vm-dev systemd-modules-load[352]: Inserted module 'parport_pc'
    9月 26 09:17:12 eric-vm-dev systemd[1]: Started Load Kernel Modules.

systemd-random-seed.service

    a service that restores the random seed of the system at early boot and saves it at shutdown. On disk the random seed is stored in /var/lib/systemd/random-seed.
    ExecStart=/lib/systemd/systemd-random-seed load
    
    # journalctl -b -u systemd-random-seed.service
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:17:01 CST. --
    9月 26 09:17:12 eric-vm-dev systemd[1]: Starting Load/Save Random Seed...
    9月 26 09:17:12 eric-vm-dev systemd[1]: Started Load/Save Random Seed.

systemd-sysctl.service

    an early boot service that configures sysctl(8) kernel parameters
    When invoked with no arguments, /lib/systemd/systemd-sysctl applies all directives from configuration files listed in sysctl.d
    ExecStart=/lib/systemd/systemd-sysctl
    
    # journalctl -b -u systemd-sysctl.service
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:32:55 CST. --
    9月 26 09:17:12 eric-vm-dev systemd[1]: Starting Apply Kernel Variables...
    9月 26 09:17:13 eric-vm-dev systemd[1]: Started Apply Kernel Variables.

systemd-timesyncd.service

    a system service that may be used to synchronize the local system clock with a remote Network Time Protocol server.
    ExecStart=!!/lib/systemd/systemd-timesyncd
    
    # journalctl -b -u systemd-timesyncd.service
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 09:32:55 CST. --
    9月 26 09:17:34 eric-vm-dev systemd[1]: Starting Network Time Synchronization...
    9月 26 09:17:34 eric-vm-dev systemd[1]: Started Network Time Synchronization.
    9月 26 09:18:02 eric-vm-dev systemd-timesyncd[825]: Synchronized to time server 91.189.89.198:123 (ntp.ubuntu.com).

systemd-udev-trigger.service

    udev Coldplug all Devices
    ExecStart=/bin/udevadm trigger --type=subsystems --action=add ; /bin/udevadm trigger --type=devices --action=add

systemd-udevd.service

    listens to kernel uevents. For every event, systemd-udevd executes matching instructions specified in udev rules. The behavior of the daemon can be configured using udev.conf
    ExecStart=/lib/systemd/systemd-udevd
    
    # journalctl -b -u systemd-udevd.service
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 10:36:29 CST. --
    9月 26 09:17:12 eric-vm-dev systemd[1]: Starting udev Kernel Device Manager...
    9月 26 09:17:18 eric-vm-dev systemd[1]: Started udev Kernel Device Manager.

systemd-update-utmp.service

    a service that writes SysV runlevel changes to utmp and wtmp, as well as the audit logs, as they occur
    ExecStart=/lib/systemd/systemd-update-utmp reboot
    
    # journalctl -b -u systemd-update-utmp.service
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 10:36:29 CST. --
    9月 26 09:17:34 eric-vm-dev systemd[1]: Starting Update UTMP about System Boot/Shutdown...
    9月 26 09:17:34 eric-vm-dev systemd[1]: Started Update UTMP about System Boot/Shutdown.

swapfile.swap

    a generator that translates /etc/fstab into native systemd units early at boot and when configuration of the system manager is reloaded
    KERNEL COMMAND LINE: fstab=, rd.fstab=, ...etc
    
    # journalctl -b -u swapfile.swap
    -- Logs begin at Mon 2019-06-03 16:58:43 CST, end at Wed 2021-09-29 10:36:29 CST. --
    9月 26 09:17:12 eric-vm-dev systemd[1]: Activating swap /swapfile...
    9月 26 09:17:13 eric-vm-dev systemd[1]: Activated swap /swapfile.