Linux administration, troubleshooting, Bash scripting, systemd, performance and Linux fundamentals
Upgrading 62 packages, including Docker and OpenSSH, on a VPS that hosts live sites: simulate first, run detached, expect a short SSH refusal, verify from outside, and plan the reboot.
WP-Cron only runs when someone visits. The exact 5-minute host cron job I use for a WordPress container, the CLI memory error I hit, and how I verified it before disabling WP-Cron.
The ZCode AppImage would not start on Kali because libfuse2 is no longer packaged there. The error, the two failed installs, the workaround that worked, the menu entry that did nothing, and the .deb and .rpm alternatives.
An AppImage that will not start usually fails for one of a handful of reasons. Each error, what it means and the exact commands to fix it: FUSE, the Electron sandbox, architecture, noexec and menu launchers.
Change a network interface MAC address in Linux with the ip command, make it permanent with NetworkManager, or use macchanger, with tested output and the pitfalls to avoid.
My Ubuntu laptop stopped booting after an update. Instead of the login screen I got a BusyBox shell and this: Gave up waiting for root file system device. ALERT! UUID=… does not exist. Dropping to a shell! (initramfs) I tried the older kernel from the GRUB menu and landed on the same prompt. What changed…
Nightly WordPress backups from a Docker VPS to Google Drive with rclone: database dump, files archive, retention, Drive upload, a restore test and the pitfalls (tar status 1, trash quota).
A defensive Linux privilege-escalation audit with real output: sudo rules, SUID and SGID files, capabilities, root-equivalent groups, writable cron paths and patch level.
A GDB cheat sheet for sysadmins with real output: reading a crash backtrace, breakpoints, watchpoints, attaching to a hung process and saving or opening core files.
A practical Linux file transfer cheat sheet: when to use scp, rsync, sftp, curl, wget, tar over ssh or netcat, with real output, resume tricks and the trailing-slash trap.