Discovering Systemd

by Seth Miller

I finally started playing with my Raspberry Pi (RP) after looking at it for a month still in the package. I looked at the available pre-built distros and immediately clicked on Arch Linux Arm. I have installed Arch Linux before on an older laptop that I have and was fascinated by it for no other reason than it was so different from the Red Hat type systems that I am so used to. If the terms pacman or rc.conf aren’t familiar to you, give Arch Linux a try and see what you think.

Instead of seeing the familiar boot process of Arch Linux when I powered up the RP, I got a sub-10 second boot with a few messages appearing after the login prompt is already on the screen. Granted, I am booting from an SD card but considering the entire compute power consists of 512MB of RAM (total being shared with the GPU) and a 700MHz processor, that is crazypants fast.

I started exploring the file system and hit one dead end after another looking for familiar files. /etc/inittab, /etc/rc.conf, chkconfig, etc. couldn’t be found. I turned to the documentation. Sure enough, SysVInit had been replaced with Systemd. I had to reset everything I knew about the Linux boot process and learn from scratch which brings me to now. I understand the basic layout and how to query systemd but that’s about it. I’m looking for some good documentation to load onto my Kindle.

My official job title is Oracle DBA but my roots lie in Linux administration. Many of my servers run Oracle Linux which is ostensibly a port of Red Hat Linux. The Wikipedia page for systemd says that RHEL 7 will at least support systemd. Despite the myriad forum posts of neophytes crying about how much more work it will be for sysadmins to support systemd, I see it as an approaching standard along with GPT replacing MBR. I want to learn about this fascinating technology and be on the leading edge of it when it hits mainstream. Next step, talk to the Oracle Linux SE’s and find out where and when.