2. Systemd
• Systemd makes a server boot quicker because it uses fewer scripts
and tries to run more tasks in parallel
• Systemd calls them units (to get a better understanding about the
problems Systemd solves
• The global Systemd configuration is stored in
the /etc/systemd directory.
• Service configuration files are located in
the /usr/lib/systemd/system directory.
4. Boot Process
• Systemd primary task is to manage the boot process and provides
information about it.
To get the boot process duration, type
Systemd-analyze
• To get the time spent by each task during the boot process, type:
Systemd-analyze blame
5. • To get the list of the critical chain of tasks during the boot process
(any additional delay of these tasks would cause an increase of the
overall boot time), type:
Systemd-analyze critical-chain
6. systemctl and systemd units
• The systemctl command is used to manage different types of systemd
objects, called units.
• A list of available unit types can be displayed with systemctl - t help
7. • Query the state of all units to verify a system startup
systemctl
Query the state of only the service units.
systemctl --type=service
The status argument may also be used to determine if a particular unit
is active and show if the unit is enabled to start at boot time
systemctl is-active sshd.service
systemctl is-enabled sshd.service
8. • List the active state of all loaded units. Optionally, limit the type of
unit.
• The --all option will add inactive units
systemctl list-units --type=service
systemctl list-units --type=service --all
