Author name: CrtMgr Team

LVM changed how I think about disk management. Before LVM, adding storage meant figuring out partitions, worrying about running out of space, and sometimes having to move data around to resize things. With LVM, extending a filesystem is usually a matter of three commands. Shrinking, snapshotting, moving storage between devices — all doable without downtime. […]

rsync is one of those tools I reach for constantly. Backups, deployments, syncing configs across servers, copying large directory trees — it handles all of it well. The basic invocation is simple, but there are a few flags and patterns that make a huge difference once you know them. The Basic Idea rsync transfers files

Log files have a way of growing quietly until they fill up your disk at the worst possible moment. I’ve seen it happen more than once — a busy web server accumulating logs, nobody checking, and then one night the disk hits 100% and everything stops. Logrotate prevents this. It’s already installed on most Linux

Knowing how to find and manage processes is fundamental sysadmin work. It’s not glamorous, but it comes up constantly — debugging a runaway process eating CPU, finding what’s holding a port open, or tracing which process opened a particular file. ps: The Process Snapshot ps shows a snapshot of current processes. The options are confusing

Cron is one of those tools that’s been around so long and is so widely used that most people learn just enough to make it work, then stop. But there are enough gotchas and useful features that it’s worth understanding properly. The Cron Daemon and Config Files crond (or cron on some systems) is the

Getting a wildcard certificate from Let’s Encrypt is a bit more involved than a regular single-domain cert. You can’t use an HTTP challenge for wildcards — Let’s Encrypt requires DNS validation, which means you need to create a TXT record to prove you own the domain. That adds complexity, but once it’s set up and

Managing TLS in Kubernetes is different enough from regular server TLS that it’s worth covering separately. The concepts are the same — certificates, private keys, certificate authorities — but the mechanics of how you provision, store, and rotate certificates involve Kubernetes-specific objects. I’ve worked through this on a few clusters. Here’s the practical picture. The

Security headers are easy to overlook. They’re not flashy — users never see them — but they add meaningful protection against a range of attacks: clickjacking, XSS, MIME sniffing, cross-origin data leaks. Adding them takes maybe 15 minutes, and scanners like securityheaders.com will grade your site. Here’s what I actually set and why each one