Self-Hosted Email Is Probably a Bad Idea
You can run your own mail server. You really, really shouldn't. Here's why.
All the articles with the tag "sysadmin".
You can run your own mail server. You really, really shouldn't. Here's why.
Long-lived connections dropping randomly? Your OS is killing them. Here's why keepalives matter and how to tune them.
Master auditd for Linux audit logging: watch critical files, audit syscalls, use aureport and ausearch, and ship logs to Loki or Elasticsearch for compliance and security monitoring.
Your VM's clock is off by minutes. NTP is running but your system still drifts. Here's why.
MTU mismatches silently break large file transfers, backups, and video calls. Here's how to find and fix the wrong frame size on your network.
DNS broke again. Here's the exact command sequence to figure out what's happening without touching a GUI.
Master LVM snapshots and thin provisioning on Linux. Learn to create, use, and merge snapshots for backups, and over-provision storage safely.
Harden SSH properly: disable password auth, switch to Ed25519 keys, configure sshd_config, set up SSH certificates with step-ca, add 2FA, and configure ProxyJump for bastion hosts.
Docker volumes vs bind mounts explained: named volumes, anonymous volumes, bind mounts, and tmpfs. Real examples for databases, dev workflows, and production.
auditd logs every system call, file access, and command. Learn ausearch, aureport, and writing audit rules.
Ventoy turns any USB drive into a multi-boot drive — drop ISOs on it and boot any OS without re-flashing the drive each time.
Never edit /etc/sudoers directly. One syntax error locks everyone out. Use visudo, understand NOPASSWD risks.