Posts
coredumpctl: Finding a Binary Crash
What is coredumpctl and how it works When a binary crashes with SEGV, the kernel can save a core dump — a snapshot of process memory at the moment of the crash. …
nftables: Basic Rule Set
Note All commands were verified on Debian/Ubuntu with the nftables package and on RHEL/CentOS 8+. On older systems you may need apt install nftables or yum …
journalctl: filters and follow
Systemd’s journal is the first place to look when a service crashes or a node starts burning CPU. journalctl does far more than dump the entire log in sequence: …
fail2ban: SSH Jail Configuration
Securing SSH against brute-force attacks is one of the first steps in hardening any server. fail2ban scans logs, detects repeated failed login attempts, and …
Chrony Instead of ntpd
Chrony has replaced ntpd as the default NTP client in most modern Linux distributions. It converges to accurate time faster, handles intermittent network …
Debian — The Swiss Army Knife of Linux
Debian isn’t the flashiest distribution, but it’s the most reliable foundation in the Linux world. Behind it stands the largest community of volunteer …
pipx: Isolated Python CLI Tools Without the Mess
pipx solves a simple but chronic problem: you need to run a Python utility once or occasionally, and pip install pollutes the global environment or leaves …
uv — Fast Python Package Manager
What is uv uv is a Python package manager written in Rust. It solves one problem: the standard pip is slow at resolving dependencies, and poetry adds its own …
tmux on Prod After Screen
Why We Switched from Screen to tmux Screen was our primary tool for about five years. After migrating the cluster to new servers it became obvious: screen drops …
Setting Up Your Own SSH Bastion Server
Why You Need a Bastion and Where It Lives A bastion is the single entry point into a private network segment. Instead of exposing SSH on every server to the …
Rsync: Backing Up a Directory Over SSH
Rsync: Backing Up a Directory Over SSH The classic way to copy a directory to a remote machine is rsync over SSH. No extra ports to open, traffic is encrypted, …
logrotate for Custom Daemons
Log rotation is missing for your daemon, the log file has grown to dozens of gigabytes, the disk is full, and monitoring is screaming. systemd-journald and …