Sysadmin

The Phone Call That Started This A client’s junior admin called me last month. Their company had just rolled out a new password policy — 14 characters, three character classes, rotation every 90 days — and the helpdesk was drowning in reset tickets. The admin was proud of the policy. The users were writing the new passwords on sticky notes stuck to their monitors. That is the entire password industry in one story: we keep making the rules harder without making the passwords better. ...

You need an AI assistant that runs on your own machine. The cloud options are good, but they are not yours. You want something that actually does things — reads your screen, controls your smart home, answers questions in Finnish or English, and never sends your data to a server you don’t control. The local LLM trend is about as practical as it sounds. It works on mid-range hardware if you pick the right model size. A sub-3B parameter model fits comfortably on consumer gear and handles everyday tasks without needing a dedicated GPU or a rack of servers. The trade-off versus cloud options is that the response times are slower, but your parents’ conversations do not become training data for a future model owned by a third party. ...

Almost nobody learns rm -rf the easy way. You read the man page, you use it carefully for a year, and then one day you watch your finger hit Enter a fraction of a second before your brain finishes checking the path. The commands that destroy data don’t punish typos. They punish the half second before the typo, when you were certain the path was right. That half second of doubt isn’t something documentation can give you. So I built a place where you can get it wrong on purpose, with nothing at stake but a score. ...

Git Things That Are Easy to Mess Up (Until They Bite You) Following up on last week’s Linux Things That Are Easy to Miss — same idea, different tool. Git is the second thing every sysadmin and dev uses daily, and like the Linux shell, it’s full of footguns that don’t bite until they really bite. ...

Linux Things That Are Easy to Miss (Until They Bite You) The other day I spent 20 minutes debugging a cron job that worked perfectly when I ran it from the shell. The fix? PATH was different in cron. That’s not a one-time thing — I trip over the same class of subtle Linux papercuts every few months. So I wrote them all down. ...

In Part 1, we built a minimal Linux system using BusyBox and a prebuilt kernel. You got a shell running inside a container, mounted pseudo-filesystems, and saw the boot sequence from init to prompt. That was the “hello world” of custom Linux. Now we’re doing the real thing. Today we’re going to compile our own kernel from source, configure only the hardware support we actually need, and compress it to under 10MB. Then we’ll rip out that hand-written init script and replace it with systemd — the same init system that runs on virtually every modern Linux distribution. Finally, we’ll get a real service running (OpenSSH) so you can actually log into your custom system remotely. ...

If you’ve been administering Linux servers for a while, you’ve probably developed a love-hate relationship with it. You know how to configure services, debug networking issues, and keep systems running. But somewhere deep down, you’ve wondered: what actually holds this thing together? I don’t mean “how does systemd work” (nobody truly knows). I mean: what happens between hitting the power button and seeing a login prompt? Today, we’re going to build our own minimal Linux system from scratch. And because I’m not a sadist, we’ll test it using Docker containers - spin it up in seconds, tear it down just as fast. ...

The Mistakes I Made (And Why They Led Me to Build My Own Password Manager) Every IT professional has a graveyard of mistakes behind them. Most of us just don’t talk about them until we’re several drinks in at a conference, or until we’re writing a blog post that we hope will save someone else the same pain. ...

The Call I Didn’t Want to Get Three weeks after leaving my job as the only IT person at a mid-sized company, my phone rang. It was Mike, the guy they hired to replace me. “Hey, uh, do you remember that backup script you set up? The one that runs on Sundays? It’s throwing an error and I can’t find where it’s configured.” ...

The Log File Problem Nobody Talks About It’s 2 PM on a Friday. Your application is throwing errors. Your manager is hovering. And you’re staring at a 50GB log file wondering where the hell to even start. Every sysadmin has been there. You know the answer is somewhere in those logs, but finding it feels like looking for a specific grain of sand on a beach. While blindfolded. In the dark. ...