Tag: linux

An AWS engineer found Linux 7.0 halved their PostgreSQL performance. The fix was kernel tuning. Here's what settings matter and why, so you're not the last to know.

Run multiple Proxmox VMs and LXC containers behind a single public IP using NAT bridging and iptables port forwarding. Updated for Proxmox VE 8.

Attackers love finding ways to go from www-data to root. Here's how they do it, and more importantly, how you harden your Linux boxes to stop them.

Out of RAM and no time to reimage? Add swap via a file on any partition using mkswap, swapon, and fstab — done in under 5 minutes.

Master bash for loops, while loops, and seq for sequential counting — iterate over files, ranges, and arrays without losing your mind.

Count files in a directory (recursively or not) with find, ls, and tree — quick one-liners for when du just isn't telling you enough.

Your disk is full and du is lying to you. ncdu, df, and find tricks to track down space hogs before your server goes down at 2 AM.

Extract tar.gz, tar.bz2, tar.xz — flags demystified, compression compared, directory extraction, and the gotchas that trip you up.

Use su with a specific shell to switch users without the default login shell — useful when /etc/passwd points to something unexpected.

logrotate keeps your /var/log from eating the disk — configure rotation schedules, compression, and retention for any service log.

Master MySQL from the command line: connect, query databases, manage users, repair tables, optimize—everything you keep Googling, one reference.

Three ways to upload an ISO to Proxmox — web UI, wget direct download, or SCP from the CLI. When each one wins, plus storage paths and checksum verification.