The kernel primitives, init systems, and tooling behind the world's most-deployed OS.
A complete walkthrough configuring unattended-upgrades (Debian/Ubuntu) and dnf-automatic (RHEL/Fedora) to apply security patches automatically, with sane limits on what gets updated unattended.
A complete walkthrough combining two or more network interfaces into a single bonded interface using NetworkManager — for redundancy, throughput, or both, depending on the mode you choose.
A complete walkthrough configuring the Linux audit daemon to watch specific files, commands, and syscalls — and actually query the resulting logs for something useful.
A complete walkthrough creating and running a lightweight systemd-nspawn container — useful for isolated testing environments without the overhead of a full container runtime.
A service refuses to start at all, and systemctl reports start-limit-hit — this is systemd's own crash-loop protection, and it requires clearing the rate limit as a distinct step after fixing the real cause.
A service that works fine with SELinux disabled fails mysteriously with it enforcing. Here's how to read audit.log, generate a targeted policy module, and fix the actual denial instead of disabling protection.
A kernel update left the system unable to boot into any menu entry, or grub-mkconfig fails outright. Here's how to regenerate a working configuration from a rescue environment.
How SELinux's label-based policy and AppArmor's path-based profiles both extend Linux's discretionary permission model, and how to work with each day to day.
Announced by Linus Torvalds in September 2024 and landing in kernel 6.12, PREEMPT_RT ended nearly two decades as an out-of-tree patchset — real-time Linux no longer needs a custom kernel build.
Announced October 28, 2018 and closed July 9, 2019, IBM's purchase of Red Hat was the largest software acquisition in history at the time — and a direct bet on hybrid cloud built around Linux and open source.