Automation, scripting, infrastructure management for DevOps, SysAdmin and other Tech stuff
User management is basic Linux administration in the same way plumbing is basic house maintenance: you can ignore it right up until the day it leaks into everything else. Bad user and group hygiene creates permission problems, weak sudo rules, confusing service ownership, and messy offboarding. Good hygiene is not glamorous, but it prevents a
Linux User and Group Management: A Practical Guide for Sysadmins Read Post »
sysctl is one of those Linux tools that attracts two kinds of bad advice. One camp never touches it and leaves obvious workload mismatches unaddressed. The other pastes giant “performance tuning” blocks from random forum posts into /etc/sysctl.conf, reboots, and hopes for free speed. I do not recommend either approach. Kernel parameters absolutely matter, but
Linux sysctl Performance Tuning Parameters Read Post »
When a service “is down,” the network is usually blamed first and understood last. I have seen people restart perfectly healthy daemons because they never checked whether the port was listening, whether a firewall was dropping the traffic, or whether the client was even talking to the right IP. Good network troubleshooting is less about
Linux Network Troubleshooting with ss, netstat, tcpdump, and Friends Read Post »
Memory problems on Linux rarely start with the machine being literally out of RAM. They usually start with someone looking at free -h, seeing almost all memory marked as used, and assuming the kernel is leaking, the database is bloated, or swap is somehow the root of every evil. I have seen good servers rebooted
Linux Memory Management and Swap Configuration Read Post »
Disk I/O problems are some of the easiest Linux performance issues to misread. CPU looks fine, memory is not completely exhausted, load average is high, and the server still feels sticky. Commands hang for a second or two. Databases stutter. Backups start slowly and then drag everything else with them. That is usually when I
Linux Disk I/O Monitoring with iostat, iotop, and Real Bottleneck Hunting Read Post »
A default MySQL or MariaDB installation is conservative — configured to work on minimal hardware. Most production servers have significantly more RAM and CPU than the defaults assume, which means the database is leaving performance on the table. These are the settings I tune when setting up a database server. Not all of them apply
MariaDB and MySQL Performance Tuning on Linux Read Post »
Running a Node.js app directly on port 80 or 443 is possible but not how I’d do it in production. Nginx in front of Node.js gives you SSL termination, static file serving, caching, compression, rate limiting, and request buffering — things Node.js can do but doesn’t do as efficiently as a dedicated web server. Here’s
Nginx as a Reverse Proxy for Node.js Applications Read Post »
SSH is more than a remote shell. The tunneling capabilities — local forwarding, remote forwarding, and dynamic SOCKS proxying — are genuinely useful for accessing services that aren’t directly reachable, and I reach for them regularly. Local Port Forwarding Local forwarding creates a tunnel: you connect to a local port, and SSH forwards the connection
SSH Port Forwarding and Tunneling: Practical Use Cases Read Post »
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.
LVM on Linux: Logical Volume Management for Flexible Disk Storage Read Post »
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
Rsync for Backups and File Synchronization: How I Actually Use It Read Post »