Systemd

What is nofile and where it lives nofile is the maximum number of open file descriptors per process. That’s not just regular files — it covers sockets, pipes, stdin/stdout/stderr, logs shipped through journald — everything counts. When nginx or a Go …

When a container crashes, logs are the first thing you need to see. docker logs looks simple, but under the hood different logging drivers are at work, and the choice affects how logs are stored, rotated, and accessed. Here is what you should know …

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. In systemd-based distributions, coredumpctl handles collecting, storing, and searching …

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: it can filter by units, priorities, time windows, and stream in real time. Below is the …

Chrony has replaced ntpd as the default NTP client in most modern Linux distributions. It converges to accurate time faster, handles intermittent network connections better, and consumes fewer resources. If your machine still runs ntpd, switching …

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 syslog-ng rotate on their own, but if your custom daemon writes directly to a file, rotation …

Logs disappeared. Server rebooted, and the familiar less /var/log/syslog returns nothing. On modern distros with systemd, logs are collected by journald and read with journalctl. Without knowing its filters, system debugging turns into guesswork. Why …

Sometimes you need to run a process under systemd’s control without writing a unit file — maybe you’re in a container without systemd, on someone else’s machine, or just need a quick one-off. That’s where systemd-run comes in. Why systemd-run The …

Your application needs to start on boot, restart on crash, and log output. Shell scripts in /etc/rc.local give you none of that. Systemd solves all three with a single declarative file. Why Write a Custom Unit File Supervisord and init scripts are …

cron works, but its logs are flat text files with no structure, and service dependencies require workarounds like embedding Requires= logic inside shell scripts. systemd-timer fixes this: unified management interface, logs in journald, dependencies …