systemd

Fix systemd 'start request repeated too quickly' on Debian 13: map 203/EXEC, 217/USER and 226/NAMESPACE to the real cause instead of raising the limit.

Fix MariaDB ERROR 2002 on Debian 13: tell a stopped server from a socket path mismatch or unix_socket root auth, with diagnostics for MariaDB 11.8.

Podman Quadlet on Debian 13: run hardened rootless containers as systemd units with podman 5.4.2, auto-updates, secrets, generator dry-run and pitfalls.

Find Linux persistence on Debian 13: malicious systemd generators, /etc/ld.so.preload, LD_PRELOAD and unpackaged units, with dpkg, debsums and auditd.

Automate Let's Encrypt on Debian 13 with certbot: timer, nginx deploy hook, OnFailure alerts, expiry checks and prep for 64- and 45-day certificates.

Set up restic backups on Debian 13: SFTP or S3 repos, a sandboxed systemd timer, forget --prune retention, append-only rest-server and restore tests.

No space left on device but df shows free space? Debug exhausted inodes, deleted files held open by processes and a bloated systemd journal on Debian 13.

Sandbox systemd services on Debian 13: score units with systemd-analyze security, harden nginx via a systemd drop-in, then debug whatever breaks.