Server Administration

Set up smartd on Debian 13 to catch failing SATA and NVMe drives: read smartctl output, schedule self-tests, and prove that alert mail actually arrives.

Debian DSA-6549-1 fixes an LZMA1 decoder memory write in xz-utils on Debian 13. Check liblzma5, update to 5.8.1-1+deb13u2 and restart affected services.

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.

Fix Postfix Relay access denied, deferred port 25 timeouts, Domain not found and SASL failures on Debian 13, with diagnostic commands and an open-relay test.

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.

Fix nginx 502 Bad Gateway with PHP-FPM 8.4 on Debian 13: map errno 13, 2, 111 and 110 in error.log to their cause, with namei, ss and cgi-fcgi checks.

DSA-6514-1 fixes 10 PHP 8.4 CVEs on Debian 13. Check for 8.4.26-1~deb13u1, restart PHP-FPM or Apache mod_php, and verify the running binary.

Fix SSH Permission denied (publickey) on Debian 13 by reading sshd's journal reason: StrictModes, key types, AllowUsers, drop-ins and ssh.socket.

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.

Debian 13 fixes BIND9 and Unbound flaws (DSA-6505-1, DSA-6507-1): how to check versions, patch, restart and verify your recursive DNS resolver.