You may or may not know that all the Linux operating systems will switch to systemd as init system.
When I saw the project at first it kinda broke the me schema of seeing things and I didn't really like the idea to switching to something new. Of course it was something completely irrational; first of all, a lot of distributions and people have been involved in the process of switching what will be the new standard of init system. The main players were systemd, SysVinit and upstart. After some months of discussion systemd is the 'winner' as best option. In Fedora 14 was being used as main init system and Debian will use it in Debian 8; Ubuntu, in its 14.10 release will use it also, stopping the development of upstart.
So, systemd will be here for a while, and some new stuff needs to be learnt. A Copying the descriptions of wikipedia:
systemd is a suite of system management daemons, libraries, and utilities designed for Linux and programmed exclusively for the Linux API. Systemd authors characterize the software suite as a "basic building block" for an operating system. For systems using it, the daemon systemd is the first process that is executed in user space during the Linux startup process. Therefore, systemd serves as the root of the user space's process tree. The name systemd adheres to the Unix convention of making daemons easier to distinguish by having the letter d as the last letter of the filename.
The atoms or primitives in systemd are called units. There are different types of units such as service, socket, device, mount, swap, target, path, timer snapshot, slice and scope.
The most common one is service, and is the equivalent of what you could found in /etc/init.d/*
The files no longer are bash scripts, but configuration files where you can use an almost infinite number of parameters and modifiers, really good documented in the systemd awful web page.
systemd also provides a set of tools to deal with logging, network, login, a 'top-like' visor of what the cgroups are doing, etc... A new set of tools to help us out with this new environment where things work a little bit different.
There are literally thousands of articles about what is systemd and what is not, its main features and its drawbacks. I strongly recomment, though, to read this series of articles from Lennard Poettering himself:
- systemd for Administrators, Part 1 : Bootup
- systemd for Administrators, Part II : Services and processes
- systemd for Administrators, Part III : Converting SysV init scripts to systemd
- systemd for Administrators, Part IV : Killing services
- systemd for Administrators, Part V : Stopping/Disabling services
- systemd for Administrators, Part VI : chroot version of systemd
- systemd for Administrators, Part VII : Reducing bootup times
- systemd for Administrators, Part VIII : New configuration files
- systemd for Administrators, Part IX : New default files, unification
- systemd for Administrators, Part X : Service instances
- systemd for Administrators, Part XI : Converting inetd services
- systemd for Administrators, Part XII : Securing services
- systemd for Administrators, Part XIII : Log and service status
- systemd for Administrators, Part XIV : Documentation on boot services
- systemd for Administrators, Part XV : Watchdogs
- systemd for Administrators, Part XVI : TTYs
- systemd for Administrators, Part XVII : journalctl
- systemd for Administrators, Part XVIII : Managing CPU, memory, etc with cgroups
- systemd for Administrators, Part XIX : Detect virtualization
After reading a little bit about it you'll get more and more used to it. If you want to try some of the examples, you can do it on Digial Ocean VPS. Here is a link of Digital Ocean referral program. If you sign up using this link you'll get 10$ free for playing around. CoreOS has systemd installed by default. Remember, 10$ is a 2 month VPS of 512MB of RAM running 24/7 or a hourly price of $0.007.
Note that I'll get $25 in credit if you sign up, so thank you very much! Its an awesome way to give me support!