Linux & Sysadmin
Red Hat, systemd, networking, storage, performance, firewalls and shell scripting.
Linux & Sysadmin articles
Choosing a Linux Filesystem
ext4 is the safe default, XFS scales, Btrfs and ZFS add snapshots and checksums at a complexity cost. Here's how to pick for a given workload.
October 24, 2026resolv.conf and systemd-resolved
On modern distros /etc/resolv.conf points at a stub resolver managed by systemd-resolved. Editing it directly usually does nothing — here's the real model.
October 24, 2026cgroups v2 Basics for Sysadmins
What cgroups v2 changed, how systemd already puts every service in one, and the handful of directives that cap a runaway service.
October 24, 2026RHEL Subscriptions and dnf Basics
Getting a fresh RHEL box to install packages: register, attach, enable repos, and understand module streams — plus the errors that block each step.
October 24, 2026Writing a Bash Script That Won't Bite You
The header and habits that turn a fragile script into one you can run in production: strict mode, quoting, trap cleanup, and shellcheck.
October 24, 2026The Linux Boot Process, Explained
Every stage from power-on to login prompt, and where to intervene when a machine won't boot.
October 24, 2026journalctl Recipes You'll Actually Use
A cheat sheet of the journalctl invocations that come up in real troubleshooting, plus how to keep logs across reboots.
October 24, 2026Bash Parameter Expansion Cheatsheet
The ${var%.*} / ${var:-default} / ${var//old/new} forms replace most calls to sed, cut, and basename. One reference, one example each.
October 24, 2026strace for Real Troubleshooting
The strace invocations that answer 'what file/host is it trying to reach' and 'why is it slow' — with the filters that make the output readable.
October 24, 2026chrony vs ntpd: Which Time Daemon and Why
chrony syncs faster, handles laptops and VMs that sleep, and is the modern default. Here's how it differs from ntpd and how to confirm your clock is actually correct.
October 24, 2026Understanding Linux Load Average
Load average isn't CPU usage. What it really counts, why a load of 8 on an 8-core box can still be fine, and how to find the real bottleneck.
October 24, 2026logrotate: Configuration That Doesn't Lose Logs
Why your app keeps writing to the rotated (deleted) file, when to use copytruncate, and how to test a logrotate rule without waiting a day.
October 24, 2026