Linux
Let's Encrypt Kept Failing After a Server Move. The Culprit Was a Second A Record.
Two A records after a migration meant round robin, and Let's Encrypt's multi-perspective validation kept hitting the old server. Diagnosis and fix.
Linux
Linux server guides from real setups: Ubuntu and Debian, systemd, firewalls, backups, mail and the gotchas that bite in production.
Linux
Mail + Web on One Server: 4 GB or 8 GB of RAM? I Measured It
Real RSS numbers from a panel box with mail and web: ClamAV eats over a gigabyte. Why summing ps lies, how to measure with smem, and when 4 GB is enough.
Linux
Lower Your DNS TTL Before You Migrate a Server (A Checklist)
A 24-hour TTL turns a server move into a day of half-broken DNS. When to lower it, how to check what resolvers see with dig, and what to tell DNS support.
Docker
My Hosting Panel's Firewall Kept Wiping Docker's iptables Chains
KeyHelp loads its firewall with iptables-restore and flushes Docker's chains. How to spot it, the quick fix, and the options to make it stick.
Linux
Postfix SNI: "map lookup problem" and TLS Alert 80 — the texthash Fix
Per-domain mail hostnames via Postfix SNI: why smtpd hit TLS alert 80 though postmap worked, the ACL fix for Let's Encrypt keys, and test commands.
Linux
KeyHelp: The Free Plesk Alternative I Moved To (and Its API Traps)
Plesk license expired, panel dead. I moved to KeyHelp: non-interactive install, one client per company, and the API gotchas that cost me hours.
Linux
Reskinning Ghost's Source Theme with Nothing but Code Injection
How my blog got its terminal/neon look on the stock Ghost Source theme: site-wide code injection, theme settings, and the 62.5% rem trap behind tiny text.
Linux
Serving a Static SPA on Apache: .htaccess Fallback, Caching, and the Container Nobody Used
Deep links to a Vite/React SPA 404 on Apache until you add a fallback. Rewrite rules, FallbackResource, cache headers, soft 404s, and what really serves.
Docker
Apache as a Reverse Proxy for Docker Apps (and the Panel Trap)
Put Docker apps behind Apache: ProxyPass, ProxyPreserveHost, X-Forwarded-Proto, WebSockets, localhost-only ports, and why a panel gives you 302/404.
Linux
Running PHP 7.4, 8.3 and 8.4 Side by Side on One Server
One server, three apps, three PHP versions: PHP-FPM per version, one pool per site, a handler per vhost and the right CLI binary for every cron job.
Linux
Plesk License Expired: What Still Works and How I Got Around It
An expired Plesk license blocks the panel and the plesk CLI, but sites and mail keep running. How I restored a mailbox anyway with mailmng-core.
Docker
Rebuilding My Ghost Blog After the Database Was Gone
My Ghost container ran outside the hosting panel, so the panel backup had none of it. How I rebuilt the blog from Markdown sources and what I verified.