Systemd

🧹 My Messy Linux Box As year passes, my Linux system, over the time, starts to get a little… Messy. My ~/Downloads directory is a digital dumping ground. It’s a collection of ISOs, test scripts, and those huge multi-gigabyte Virtual Machine images I need to test once and then forget about. Add to that ~/Pictures/Screenshots, which is overflowing with thousands of quick snaps I’ll never look at again. Disk space is cheap nowadays, but I like to have things nice and clean. I could go in and manually clean it… But who remembers to do that ? ...

💭 What ? Imagine a web server that only starts when someone actually tries to access it. Or a database that spins up only when a query comes in: this is the magic of socket activation. The concept is not new, as old-school sysadmins may are used to see something like inetd or xinetd for on-demand service activation in the past. As some cool projects like cockpit have already started using this little-known feature, in this blog post we’ll see the basics and try to get familiarity with the tooling. ...

intro Resource isolation is an hot topic these days, and it’s a problem excellently solved by containerization. However, we can achieve isolation between internal tasks of an operating system by leveraging a technology exposed by the kernel: cgroups. This component is also used by Docker, and other Linux container technologies. Cgroups are the Linux way of organizing groups of processes: roughly speaking a cgroup is to a process what a process is to a thread: one can have many threads belonging to the same process, and in the same way one can join many processes inside the same cgroup. ...