Systemd on Ubuntu

What is SYSTEMD?

SYSTEMD is a system and session manager under Linux that is compatible with SysV and LSB startup scripts. SYSTEMD provides aggressive parallel processing capabilities, using sockets and D-bus activation start-up services that enable daemons to start on demand, keep track of processes with Linux cgroups, support backup and recovery of System State, maintain manual and automatic mount points, Implements the executable service control logic based on the dependency relationship.

More information can be found on the SYSTEMD home page.

Personal Package Archive (PPA) address

SYSTEMD and related packages can be found in this PPA, to use the PPA, please follow the method below to add it to your list of software sources:

Add-apt-repository ppa:pitti/systemdapt-get Update

Installing SYSTEMD

Install systemd libpam-systemd systemd-ui

This will allow SYSTEMD and upstart to coexist in the system, if you want to replace the upstart, you need to install the SYSTEMD-SYSV this package, the package provides the reboot and other commands to the original program provided by the same command to replace.

Configuration of the boot loader

After SYSTEMD is installed, the computer may still start upstart by default, in order for the system to be used SYSTEMD, the following parameters must be specified in the kernel command line in the GRUB configuration file:

Vim/etc/default/grub
grub_cmdline_linux_default= "Quiet Splash init=/lib/systemd/systemd"

After you modify the configuration, the following command requires the changes to take effect

Update-grub

SYSTEMD when the following warning message appears on startup

 Make file Mount (8) output.

Well, it's best to do as suggested and replace the/etc/mtab. Otherwise, not only does mount run abnormally, but DF is the same, and other programs that view the Mount list are likely to have problems. You can change it as follows:

LN -fs/proc/self/mounts/etc/mtab

Use of SYSTEMD

Start

If the SYSTEMD does not start properly, you can try adding the following parameters to the kernel line in the GRUB configuration:

Init=/lib/systemd/systemd Systemd.unit=emergency.service

systemd.unit= Specifies the target state to which the system is to be booted (similar to the sysvinit specified RunLevel).
Emergency.service launches an emergency mode bash shell on the virtual terminal and does not attempt to start any other services.

Post-boot control systemd

The main command to control SYSTEMD is systemctl. Some sub-commands are as follows:

Systemctl list-units--List all units (unit, which represents "tasks or services")

Systemctl start [name ...]--start (or activate) one or more units

Systemctl Stop [name ...]--stop (or hang) one or more units

Systemctl Enable [name ...]--enabling one or more units

systemctl Disable [name ...]--deactivate one or more units

Systemctl reboot--shutting down or rebooting the system

To view the entire list of commands, see the Man manual page of Systemctl (1).
Systemadm is the Systemctl graphical user interface front end.

Systemd on Ubuntu