Useful Systemd commands
Find the time taking services during system boot
systemd-analyze blame
7.239s libvirtd.service
4.528s systemd-udev-settle.service
2.829s dracut-initqueue.service
2.043s plymouth-quit-wait.service
1.541s vboxdrv.service
1.435s udisks2.service
1.149s sssd.service
1.066s gssproxy.service
1.065s zookeeper.service
632ms lvm2-monitor.service
411ms lightdm.service
410ms systemd-logind.service
238ms initrd-switch-root.service
172ms accounts-daemon.service
137ms polkit.service
121ms sysroot.mount
106ms gpd.service
99ms systemd-fsck@dev-disk-by\x2duuid-BE47\x2d662D.service
92ms systemd-tmpfiles-clean.service
82ms upower.service
81ms rtkit-daemon.service
79ms chronyd.service
79ms lm_sensors.service
Find total time to boot
systemd-analyze
Startup finished in 8.359s (firmware) + 5.486s (loader) + 2.499s (kernel) + 3.289s (initrd) + 14.384s (userspace) = 34.018s
graphical.target reached after 14.380s in userspace
Find the dependencies of service
systemctl list-dependencies --reverse plymouth-quit-wait.service
plymouth-quit-wait.service
● └─multi-user.target
● └─graphical.target
Find the reverse dependencies of service
systemctl list-dependencies docker.service
docker.service
● ├─containerd.service
● ├─docker.socket
● ├─system.slice
● ├─network-online.target
● └─sysinit.target
● ├─dev-hugepages.mount
● ├─dev-mqueue.mount
● ├─dracut-shutdown.service
● ├─import-state.service
● ├─iscsi-onboot.service
● ├─kmod-static-nodes.service
● ├─ldconfig.service
● ├─loadmodules.service
● ├─lvm2-lvmpolld.socket
● ├─lvm2-monitor.service
● ├─multipathd.service
● ├─nis-domainname.service
● ├─plymouth-read-write.service
● ├─plymouth-start.service
● ├─proc-sys-fs-binfmt_misc.automount
● ├─selinux-autorelabel-mark.service
● ├─sys-fs-fuse-connections.mount
● ├─sys-kernel-config.mount
● ├─sys-kernel-debug.mount
● ├─systemd-ask-password-console.path
● ├─systemd-binfmt.service
● ├─systemd-firstboot.service
● ├─systemd-hwdb-update.service
● ├─systemd-journal-catalog-update.service
● ├─systemd-journal-flush.service
● ├─systemd-journald.service
● ├─systemd-machine-id-commit.service
● ├─systemd-modules-load.service
● ├─systemd-random-seed.service
● ├─systemd-sysctl.service
● ├─systemd-sysusers.service
● ├─systemd-tmpfiles-setup-dev.service
● ├─systemd-tmpfiles-setup.service
● ├─systemd-udev-trigger.service
● ├─systemd-udevd.service
● ├─systemd-update-done.service
● ├─systemd-update-utmp.service
● ├─cryptsetup.target
● ├─local-fs.target
● │ ├─-.mount
● │ ├─boot-efi.mount
● │ ├─boot.mount
● │ ├─ostree-remount.service
● │ └─systemd-remount-fs.service
● └─swap.target
Find Active Services
systemctl list-units --type=service --state=active
Find Running Services
systemctl list-units --type=service --state=running
Find Enabled Units
systemctl list-unit-files --state=enabled
Find Loaded Services
systemctl list-units --type=service --state=loaded
View last boot log
journalctl -b
View errors in services
journalctl -xe
View kernel logs
``` journalctl -k